Experts on Call1. Awad IA, Little JR, Akrawi WP, et al: Intracranial Dural Arteriovenous Malformations: Factors Predisposing to an Aggressive Neurological Course. J Neurosurg 1990;

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Experts on Call

The Canadian Journal of Diagnosis / May 201320

Answers to your questionsfrom our medical experts

Dural AV Malformation and Hemorrhage

If a patient has a dural arteriovenous (AV) malformation with proven retrogradeblood flow, is treatment required urgently?

Submitted by: Steve Choi, MD, Oakville, Ontario?

About 15 to 20% of patients with intracranialdural AV malformations may suffer from intracra-nial and subarachnoid hemorrhage. Somepatients may have other complications, such asseizures.

Dural AV malformations have been classifiedinto benign or aggressive types depending onthe pattern of blood flow. Retrograde blood flowis the most important risk factor for aggressivebehaviour of dural AV malformations.1 Several

studies have emphasized the importance of ret-rograde blood flow in the development of hem-orrhage; therefore, neurosurgical consultationshould be obtained.

Reference1. Awad IA, Little JR, Akrawi WP, et al: Intracranial Dural Arteriovenous

Malformations: Factors Predisposing to an Aggressive NeurologicalCourse. J Neurosurg 1990; 72(6):839–850.

Answered by:Dr. Abdul Qayyum Rana and Mr. Mohammad A. Rana

Monitoring Hashimoto’s Thyroiditis

Hashimoto’s thyroiditis is the most common causeof chronic primary hypothyroidism. Pre-pregnan-cy, the patient needs to be monitored clinically (forsymptoms of hypothyroidism and goiter/compres-sive symptoms) and biochemically with a thyroidstimulating hormone (TSH) test to ensure euthy-roidism. Generally, this needs to be done at leastonce per year or earlier if there are symptoms ofhypothyroidism, compressive symptoms relatedto the goiter, significant changes in health/weight,drugs that may alter 1-thyroxine levels (e.g., med-ications, such as calcium or iron, drugs thatincrease metabolism, and oral contraceptive pills

that lower free T4), concerns of non-adherence, orsuspicion of malabsorption. The patient alsoneeds to have a repeat TSH test six weeks after adose change of 1-thyroxine. Of course, one needsto clinically monitor for other autoimmune condi-tions and perform laboratory testing if clinical con-cerns arise. During pregnancy, the requirement of1-thyroxine increases, so, at the onset of pregnan-cy, the dose needs to be increased by 25 to 50%and evaluation, especially with a TSH test, shouldbe done in each trimester.

Answered by:Dr. Ally Prebtani

How do I best monitor a patient with Hashimoto’s thyroiditis (chronic autoimmune thyroiditis) before and during pregnancy?Submitted by: Ilona Amstutz, MD, Charlie Lake, British Columbia

?


Experts on Call

Resuming Activity after Major Cardiac Events

When is it safe to resume work, exercise, sexual activities, etc. after myocardialinfarction, coronary artery bypass graft surgery, and unstable angina?Submitted by: A. Foda, MD, Winnipeg, Manitoba

?Patients should gradually resume their usual activ-ities over one to two weeks after hospital dis-charge. Patients with myocardial infarction com-plicated by heart failure should, if possible, beenrolled in an exercise rehabilitation program.Patients can resume driving 48 hours after non-STelevation myocardial infarction treated with percu-taneous coronary intervention and can return towork in one to two weeks. Patients with ST eleva-tion myocardial infarction or those who haveundergone coronary artery bypass surgery candrive in four weeks and probably return to work infour to eight weeks, depending on their exercisecapacity and the nature of their work (mentalstress and physical activity involved).

Walking is recommended immediately on hos-pital discharge. More strenuous exertion, such asrunning or weight lifting should be delayed for twoto three months after myocardial infarction or car-diac surgery.

Sexual activity is associated with a smallincrease in the risk of myocardial infarction in the

two hours following intercourse. Sex is consideredsafe one week after uncomplicated myocardialinfarction, as long as the patient does not haveangina with mild to moderate physical activity.Patients should wait six to eight weeks followingcardiac surgery or until the sternotomy is wellhealed before having sexual intercourse.

Elective travel involving flying on a commercialaircraft should be delayed for six to eight weeksfollowing myocardial infarction because of thelower partial pressure of oxygen in the aircraftcabin. The patient may fly one to two weeks fol-lowing uncomplicated, low-risk myocardial infarc-tion to return to their home.1

Reference1. CCS Consensus Conference 2003: Assessment of the Cardiac Patient

for Fitness to Drive and Fly — Executive Summary. www.ccs.ca/down-load/consensus_conference/consensus_conference_archives/2003_Fitness_ES.pdf. Accessed: March 3, 2013.

Answered by: Dr. Bibiana Cujec


Experts on Call

Inferior Vena Cava Sarcomas

How common are inferior vena cava sarcomas? Should we screen for themwithin a family if one member is affected? Submitted by: Andrea Kirsh, MD, Toronto, Ontario

?Leiomyosarcomas of the inferior vena cava arevery rare, malignant, soft tissue tumours, and onlya few hundred cases have been reported in the lit-erature since it was initially described in 1871.1–4 Itaffects adults in the fifth or sixth decade of life,with a female predominance. Symptoms andsigns may be absent, and, if they are present, theyare often non-specific (e.g., abdominal pain, backpain, weight loss, leg swelling). Diagnostic work-up includes CT of the chest, abdomen, and pelvis.A multidisciplinary approach to management isessential; surgical resection is the primary main-stay of treatment, if feasible, with consideration forradiotherapy and chemotherapy. Due to the lowprevalence and rarity of the tumour, however, any

screening test would be associated with a low positive predictive value and, therefore, is notrecommended.

References1. Hines OJ, Nelson S, Quinones-Baldrich WJ, et al: Leiomyosarcoma of

the Inferior Vena Cava: Prognosis and Comparison withLeiomyosarcoma of Other Anatomic Sites. Cancer 1999; 85(5):1077–1083.

2. Ito H, Hornick JL, Bertagnolli MM, et al: Leiomyosarcoma of the InferiorVena Cava: Survival after Aggressive Management. Ann Surg Oncol2007; 14(12):3534–3541.

3. Tilkorn DJ, Hauser J, Ring A, et al: Leiomyosarcoma of IntravascularOrigin — A Rare Tumor Entity: Clinical Pathological Study of TwelveCases. World J Surg Oncol 2010; 8:103.

4. Italiano A, Toulmonde M, Stoeckle E, et al: Clinical Outcome ofLeiomyosarcomas of Vascular Origin: Comparison withLeiomyosarcomas of Other Origin. Ann Oncol 2010; 21(9):1915–1921.

Answered by:Dr. Roger Y. Tsang

The Canadian Journal of Diagnosis / May 2013 25

Experts on Call

Complications with Large Babies

Please discuss extra large babies — etiology, risks, and preventative measuresfor avoiding complications.Submitted by: I. D'Souza, MD, Toronto, Ontario

?Risk factors for fetal macrosomia are high mater-nal body mass index, multiparity, diabetes, post-term pregnancy, previous macrosomic infant,excessive weight gain in pregnancy, Hispanic orAfrican-American ethnicity, male fetus, and birthweight over 4,000 g. The most common causesare constitutional, maternal diabetes and/ormaternal obesity/excessive gestational weightgain. Once these have been ruled out, then thepossibility of one of the rare syndromes associat-ed with excessive fetal growth should be consid-ered and consultation with a geneticist for prena-tal diagnosis should be sought.1

The maternal risks of fetal macrosomia areprotracted/arrested labour, operative vaginaldelivery, Caesarean section, genital lacerations,postpartum hemorrhage, and uterine rupture(rare). Fetal risks include shoulder dystocia,which can lead to birth trauma (brachial plexusinjury, fracture), and asphyxia.2

Methods to avoid fetal macrosomia includelimited maternal weight gain (20 pounds), weightloss prior to conception in obese women, andwell-controlled blood sugars in women with dia-betes (especially preconception in those withtype 1 or type 2 diabetes).

As shoulder dystocia can not be accuratelypredicted, routine prophylactic Caesarean and

labour induction are not recommended for suspected macrosomia. Instrumental deliveryappears to be the risk factor most associatedwith shoulder dystocia and permanent brachialplexus injury. A woman with a previous shoulderdystocia should be counselled about the risk ofrecurrence, especially if:

• The maternal pre-pregnancy weight is higherthan in the index pregnancy

• There is greater maternal weight gain duringthe current pregnancy than in the index pregnancy

• There is a longer second stage than in theindex pregnancy

• There is suspected fetal macrosomia3

Once all options have been discussed, themother and the obstetrician can make a decisionabout the route of delivery.

References1. Ju H, Chadha Y, Donovan T, et al: Fetal Macrosomia and Pregnancy

Outcomes. Aust N Z J Obstet Gynaecol 2009; 49(5):504–509.2. Siggelkow W, Boehm D, Skala C, et al: The Influence of Macrosomia on

the Duration of Labor, the Mode of Delivery and IntrapartumComplications. Arch Gynecol Obstet 2008; 278(6):547–553.

3. Bjørstad AR, Irgens-Hansen K, Daltveit AK, et al: Macrosomia: Mode ofDelivery and Pregnancy Outcome. Acta Obstet Gynecol Scand 2010;89(5):664–669.

Answered by: Dr. Victoria Davis


Experts on Call

Treating Typhoid Fever

How is typhoid fever treated? What about contacts? Do they need antibiotics orvaccines?Submitted by: Nathalie Leroux, MD, Fenwick, Ontario

?Typhoid fever is an enteric bacterial infectioncaused by Salmonella enterica, subtypes Typhiand Paratyphi A, B, and C.1 Optimal antimicrobialmanagement of patients with enteric feverdepends on local patterns of antimicrobial resis-tance and the results of antimicrobial susceptibil-ity testing of the Salmonella isolated from the indi-vidual patient. Quinolones (e.g., ciprofloxacinorally for five to seven days) remain the treatmentof choice in patients from areas where isolateswith decreased susceptibility to quinolones (DSQ)are uncommon, such as Africa and South andCentral America.2,3 Ceftriaxone is preferred incases from areas where DSQ is common (e.g.,the Indian Subcontinent or Southeast Asia);azithromycin p.o. daily for seven days is an alter-nate option, especially for patients not requiringhospitalization.2,3

Depending on the antibiotic used, between 1 and 4% of treated patients will become chroniccarriers.2 In some cases, the organism evadesantibiotics by sequestering itself within gallstones.To treat the carrier state, amoxicillin or ampicillinplus probenecid, trimethoprim-sulfamethoxazole,and ciprofloxacin can be taken for several months;in some cases, cholecystectomy is necessary.2

Education should be given to the patientregarding the importance of completing the

course of antibiotics, the possibility of relapse,persisting excretion, and the need for good per-sonal hygiene and precautions in food prepara-tion. Food handlers and workers in certain profes-sions (e.g., daycare workers) are generally exclud-ed from work until they have had at least two con-secutive negative fecal specimens.

Contacts are generally not provided with treat-ment or vaccination, but they should be educatedabout the disease so as to reduce the risk of trans-mission and to allow for early identification if theydevelop symptoms. The decision to screen con-tacts of cases is dependent upon the extent ofcontact and the likely source of the case’s infec-tion. Typhoid vaccination is recommended for per-sons with intimate exposure to a documentedtyphoid fever carrier, such as those with continuedhousehold contact.

References1. Crump JA, Mintz ED: Global Trends in Typhoid and Paratyphoid Fever.

Clin Infect Dis 2010; 50(2):241–246. 2. Sánchez-Vargas FM, Abu-El-Haija MA, Gómez-Duarte OG: Salmonella

Infections: An Update on Epidemiology, Management, and Prevention.Travel Med Infect Dis 2011; 9(6):263–277.

3. Committee to Advise on Tropical Medicine and Travel (CATMAT): Feverin the Returning International Traveller — Initial AssessmentGuidelines. CCDR 2011; 27(ACS-3).

Answered by:Dr. Ameeta Singh


Experts on Call

Treating Recurrent Hot Tub Folliculitis

What is the treatment of recurrent hot tub folliculitis (Pseudomonas aeruginosa)?Submitted by: Roshan Dheda, MD, Bradford, Ontario?

Hot tub folliculitis is caused by a Pseudomonasaeruginosa infection of the skin and specifical-ly the hair follicles, which arises from hot tubsor swimming pools that become contaminatedwith high enough levels of Pseudomonasaeruginosa.

Normally, patients do not need to be treatedfor hot tub folliculitis, as it is self-limited and theitchy papules and pustules will resolve sponta-neously over approximately one week if thepatient is no longer exposed to the contami-nated water source. If a patient has severe hottub folliculitis, he or she can be treated with afluoroquinolone, usually ciprofloxacin 500 mgp.o. b.i.d. for five days.

The usual reason that hot tub folliculitisdevelops is that the hot tub or swimming pool is being improperly chlorinated or bromi-nated. Increased water alkalinity promotesPseudomonas overgrowth. The best treatmentfor hot tub folliculitis is to ensure proper chlori-nation or bromination and proper pH of the

water. Outbreaks require complete drainage ofthe contaminated water, refilling the hot tub orswimming pool with fresh water, and ensuringproper chlorine or bromine levels and pH of thewater.

The question asked is about recurrent hottub folliculitis. Recurrent hot tub folliculitiswould only be seen if the patient went back intothe contaminated hot tub or swimming poolwithout having properly cleaned it (usingappropriate chemicals and maintaining properpH) or if the hot tub or swimming pool was notbeing properly maintained and, therefore,became recontaminated with pseudomonaseven after initial draining of the contaminatedwater source. If this is the case, it may be nec-essary to seek the advice of a hot tub or poolmaintenance company that is experienced inmaintaining proper water conditions for humanexposure.

Answered by: Dr. Richard Haber


Experts on Call

Compression of Foot Nerves

Please discuss compression of the nerves in the foot. If it’s not tarsal tunnel,what is it? Does all numbness in the foot require EMG or will most conditionsimprove spontaneously?Submitted by: Gayle Garber, MD, Conception Bay South, Newfoundland

?Nerve entrapment can occur at various sites in thefoot. It is often caused by trauma, pressure creat-ed by swelling, and tight shoes, in addition totarsal tunnel syndrome. Other factors that mayresult in paresthesia of the feet include certaindrugs used in chemotherapy, antiviral agents orantibiotics, tumours compressing a nerve, hepaticor renal disease, vitamin deficiencies, herniateddisc in the lumbar region, and infectious diseases,such as complications from Lyme disease, as wellas viral infections. Nerve entrapment may causeshooting, burning pain or sensitivity, and thesesymptoms can be very similar to polyneuropathy.Diabetes is one of the most common causes ofpolyneuropathy. Polyneuropathy is characterizedby spontaneous burning or shooting pain in the

feet. It often occurs at night and may fluctuate overthe course of the disease. It may be accompaniedby a gradual loss of feeling in the feet that starts inthe toes and progresses upwards.1 Dependingupon the pathology, some of these cases mayimprove if the underlying cause is addressed.Most patients with these symptoms require nerveconduction studies with or without EMG for furtherassessment and confirmation of diagnosis, whichalso depends upon clinical suspicion.

Reference1. Hovaguimian A, Gibbons CH: Clinical Approach to the Treatment of

Painful Diabetic Neuropathy. Ther Adv Endocrinol Metab 2011; 2(1):27–38.

Answered by:Dr. Abdul Qayyum Rana andMr. Mohammed A. Rana�

Experts on Call

When to Discontinue Prostate Screening

Is there an age at which routine prostate screening should be discontinued inmen?Submitted by: D. Berendt, MD, Edmonton, Alberta

?If one believes in screening for prostate cancer(true screening is likely not necessary), PSA mea-surements for detection of possible prostate can-cer are not recommended in patients with lessthan a 10-year life expectancy. This correlates with

the rule that PSA determination is not necessary inpatients over the age of 75

Answered by:Dr. Michael Greenspan�


Experts on Call

Isolated Ventricular Noncompaction

What is isolated ventricular noncompaction, and how is it best diagnosed andmanaged?Submitted by: Sebouh Matossian, MD, New Westminster, British Columbia

?Ventricular noncompaction is a rare, primarygenetic cardiomyopathy with coarse trabecula-tions and deep intertrabecular recesses in theleft ventricle. The left ventricular systolic func-tion is usually decreased.

Patients can present with heart failure, atrialor ventricular arrhythmias, or thromboembolicevents. Thrombi form in the deep recesses ofthe left ventricle and can embolize. Echocar-diogram is usually diagnostic, showing a mesh-work of trabeculations in the thickened endo-cardial layer and a thin, compacted epicardiallayer (ratio of non-compacted to compactedmyocardium > 2:1 at end-systole in the shortaxis view). If the echocardiogram is non-diag-nostic, cardiac magnetic resonance imaging

can provide superior spatial resolution of theapex and lateral wall to make the diagnosis.Left ventricular (LV) ejection fraction is often < 40%.

Management is similar to patients with sys-tolic dysfunction in terms of ß-blocker and ACEinhibitor therapy. Patients with LV ejection frac-tion < 40% or atrial fibrillation should be consid-ered for chronic warfarin therapy. Yearly Holtermonitors are recommended to detect arrhyth-mias. A defibrillator is considered if LV ejectionfraction is < 35% and heart failure symptoms arepresent. First-degree relatives should bescreened with ECG and echocardiography.

Answered by:Dr. Bibiana Cujec

Experts on Call

Preventing UTI Recurrences

How do you prevent urinary tract infection (UTI) recurrences in susceptiblepatients?Submitted by: I. D' Souza, MD, Toronto, Ontario

?To prevent recurrences, the first step is properantibiotic choice and duration of treatment. Inmales, underlying contributing factors, such asBPH, might require treatment with α-blockersand/or 5α-reductase inhibitors. In females,make sure that proper bladder emptyingoccurs after sexual intercourse. In olderfemales, hormonal imbalance can result in local

vaginal factors that might contribute to a UTI.Topical, not systemic, therapy can be benefi-cial. Nightly prophylaxis with nitrofurantoinq.h.s. for 6 to 12 weeks is often beneficial forprevention of recurrent UTIs.

Answered by:Dr. Michael Greenspan�


Experts on Call

Steroids and Acute Bacterial Meningitis

What is the role of steroids in acute bacterial meningitis in adults?Submitted by: Pin Li, MD, Calgary, Alberta?

Animal studies have shown that the outcome frombacterial meningitis is related to the severity ofinflammation in the subarachnoid space andcould potentially be improved by modifying theinflammatory response (e.g., with dexametha-sone).1 A meta-analysis of trials examining theeffect of steroids in adults with bacterial meningi-tis concluded that adjunctive dexamethasone didnot significantly reduce mortality, neurological dis-ability, or severe hearing loss in patients with bac-terial meningitis.2 However, a post-hoc analysissuggested that adjunctive dexamethasone treat-ment reduced the rate of hearing loss in survivors(odds ratio 0.77; 95% CI: 0.60–0.99; p = 0.04) andwas not associated with an increased risk ofadverse events. In at least one study, the benefitwas greatest in patients with pneumococcalmeningitis.3

Guidelines from the Infectious DiseasesSociety of America recommend the use of adjunc-tive dexamethasone in patients with suspected orproven community-acquired bacterial meningitisbut only in high-income countries.4 If used, dex-amethasone treatment should be started with, or

before, the first dose of antibiotics at a dose of0.15 mg/kg q.6.h. for two to four days, with thefirst dose administered 10 to 20 minutes before, orat least concomitant with, the first dose of antimi-crobial therapy. Dexamethasone should only becontinued if the cerebrospinal fluid (CSF) Gramstain reveals gram-positive diplococci or if bloodor CSF cultures are positive for Streptococcuspneumoniae. Adjunctive dexamethasone shouldnot be given to adult patients who have alreadyreceived antimicrobial therapy, because adminis-tration of dexamethasone in this circumstance isunlikely to improve patient outcome.4

References1. Mook-Kanamori BB, Geldhoff M, van der Poll T, et al: Pathogenesis and

Pathophysiology of Pneumococcal Meningitis. Clin Microbiol Rev2011; 24(3):557–591.

2. van de Beek D, Farrar JJ, de Gans J, et al: Adjunctive Dexamethasonein Bacterial Meningitis: A Meta-analysis of Individual Patient Data.Lancet Neurol 2010; 9(3):254–263.

3. de Gans, van de Beek D: Dexamethasone in Adults with BacterialMeningitis. N Engl J Med 2002; 347(20):1549–1556.

4. Tunkel AR, Hartman BJ, Kaplan SL, et al: Practice Guidelines for theManagement of Bacterial Meningitis. Clin Infect Dis 2004; 39(9):1267–1284.



Experts on Call

Notochord Remnant

? While investigating a case of osteoporosis in a young adult male, a plain x-rayrevealed evidence of a notochord remnant. What is that? What other tests arerequired? What is the clinical significance of this finding?

Submitted by: Clayton Reynolds, MD, Victoria, British Columbia

Notochord remnants are usually benign physio-logical variants.1 The majority of notochord rem-nants are asymptomatic and are of no pathologi-cal consequence. These findings are typically inci-dental in 30- to 40-year-old individuals on plain x-ray radiographs.

Rarely, however, persistent notochordal nests,or remnants, can be associated with chordomas,which are rare neoplasms that are most common-ly located at the occipital-cervical junction or in thesacrococcygeal segments. If the patient’s clinicalpresentation is concerning for possible pathologyat the location of the notochord remnant, then anMRI of the spine with or without the brain shouldbe performed to differentiate between a benignphysiological finding and an aggressive lesion. IfMRI is not readily available, then a CT scan maybe performed.

Osteoporosis in young males is uncommonand should be fully investigated.2 Important caus-es of osteoporosis in young males include alcoholabuse, glucocorticoid excess, hypogonadism,hyperparathyroidism, malignancy, and gastroin-testinal disorders. If an etiology for the osteoporo-sis is not determined, given the presence of anotochord remnant, further imaging of the noto-chord remnant may be considered.

References1. Stambough JB, Cole J, Stambough JL, et al: Persistent Notochordal

Remnants of the Lumbar Spine: A Case Study and Literature Review.Current Orthopaedic Practice 2011; 22(1):E1–E4.

2. Khosla S, Amin S, Orwoll E: Osteoporosis in Men. Endocr Rev 2008;29(4):441–464.

Answered by: Ms. Julie Beveridge and Dr. Roger Y. Tsang

Experts on Call

?Identifying Pernicious Anemia

If a patient has macrocytic anemia with lowSerum B12 levels, what test should be done toprove the existence of pernicious anemia?Submitted by: Constantine Vitou, MD, Town of Mount Royal, Québec

In a patient with macrocytic anemia and low serum B12 lev-els, a Schilling test is required to prove the existence of per-nicious anemia. However, this test is no longer available inmost centres, and, unfortunately, there are no good alterna-tives to the Schilling test. Some have advocated intrinsic fac-tor antibody testing (poor sensitivity), serum gastrin orpepsinogen I testing (poor specificity), or a combination forpernicious anemia. However, these tests are expensive, diffi-cult to obtain, and do not help to definitively diagnose theunderlying cause.

Please note that a Schilling test is ideally used for deter-mining the etiology of B12 deficiency not to confirm it. Thereare many other causes of macrocytic anemia that should beruled out. Further, a low serum B12 level does not mean thatthere is a functional B12 deficiency. The reason for this is thatserum B12 level is defined as the total B12 bound to proteinstranscobalamin I, II, and III. Only the small fraction of vitaminB12 bound to transcobalamin II is important physiologicallyfor cellular function.

To confirm B12 deficiency, one should have at least twoseparate values of low serum B12 levels or a low serum B12value with an elevated methylmalonic acid level. An elevatedfasting homocysteine level will also be present.

Answered by:Dr. Cyrus Hsia


Experts on Call

?When to Worry about Skin Cancer

When should I worry about skin cancers? What do I look for?Submitted by: Michael Davis, MD, Toronto, Ontario

The most common skin cancers are non-melanoma skin cancers (basal cell carcinomaand squamous cell carcinoma) and melanoma.There are many other types of skin cancer, butthey are much less frequent.

As both nonmelanoma skin cancers andmelanoma are associated with cumulativeultraviolet exposure (both UVB and UVA), mostcases are seen in older patients who have hada lot of sun exposure over the years. Outdoorworkers and patients who burn easily are mostat risk.

Theoretically, clinicians should perform acomplete skin exam on all patients, with extravigilance in older patients and patients whoburn easily, have had several sunburns, andhave accumulated a lot of ultraviolet exposure.Any lesion that does not heal after severalmonths or is painful, itching, or bleeding shouldbe assessed and biopsied if there is somedoubt as to the clinical diagnosis. If in doubt,refer the patient to an experienced dermatolo-gist for assessment.

Classic nodular basal cell carcinoma will havea translucent appearance with a rolled border

and superimposed telangiectasias, and it mayulcerate. However, there are other presentationsof basal cell carcinoma, including the appear-ance of a non-healing, erythematous patch orplaque (superficial basal cell carcinoma) or ascar-like lesion (sclerosing basal cell carcinoma).They may occasionally be pigmented.

Squamous cell carcinomas are frequentlyerythematous, hyperkeratotic papules orplaques that are scaly or crusted and may alsobe ulcerated.

In regards to melanoma, the most importantrisk factor is the number of moles, and, there-fore, patients with > 50 nevi should be careful-ly screened. Clinicians should use the ABCDEcriteria to evaluate nevi, and, when in doubt, anexcisional biopsy should be done or the patientshould be referred to a dermatologist who willexamine him or her with a dermatoscope anddecide if the nevi require biopsy or can just befollowed.

Answered by:Dr. Richard Haber


Experts on Call

?

Investigating Hypoglycemia in Non-diabetics

How do you investigate hypoglycemia in non-diabetic patients?Submitted by: N. Aleykina, MD, Corner Brook, Newfoundland

The most common cause of non-diabetic hypoglycemia in the outpatient setting is exoge-nous insulin or insulin secretagogue use (e.g.,sulphonylureas, meglitinides) and certain otherdrugs, such as quinine. After drugs, an insulino-ma needs to be considered, although this tumouris quite rare. The most important thing to do is totake a very thorough history to documentWhipple’s triad. Whipple’s triad includes symp-toms of neuroglycopenia, such as confusion,blurry vision, change in behaviour, drowsiness,and seizures; rapid relief of symptoms with car-bohydrate ingestion; and confirmation of venoushypoglycemia < 2.2 to 2.5 mmol/L (since capil-lary glucose monitoring can be inaccurate butmay be useful in suspected venous hypo-glycemia). It is also important to note any other

drugs that the patient may be using, includingnon-prescription and herbal remedies; anyaccess to hypoglycemic drugs (working in apharmacy/hospital, family members with dia-betes mellitus); and a history of mental illness,which may be indicative of surreptitious use. Ifnon-diabetic hypoglycemia is suspected basedon the above indications, a referral to an endocri-nologist should be made for further investiga-tions and management. If Whipple’s triad isestablished, at the time of venous hypoglycemia,blood levels of insulin, C-peptide, proinsulin, sec-retagogue drug levels, ß-hydroxybutarate, andglucose response to IV glucagon will help withthe diagnosis and etiology.

Answered by:Dr. Ally Prebtani


Experts on Call

Vaccinating for HPV Post Infection

Can we vaccinate women with know HPV (cervical, abnormal Paps) with the newHPV vaccine?Submitted by: Rita Farah, MD, Montréal, Québec

?The bivalent and quadrivalent human papillo-mavirus (HPV) vaccines have been found to besafe when given to people who are alreadyinfected with HPV; however, they will not treatinfection, and they provide maximum benefitwhen administered prior to sexual activity.1

There is emerging evidence that some individ-uals infected with HPV may still get residualbenefits from vaccination, even if they areinfected with one or more of the types includedin the vaccines. However, this possibility is stillunder investigation. At present, there is no gen-erally available test to show whether an individ-ual has been exposed to HPV. The currentlyapproved HPV DNA test shows only whether aperson has a current HPV infection, and it iden-tifies the HPV type, but it does not provideinformation on past infections. The Centers forDisease Control and Prevention recommend

that women who have abnormal Pap testresults, which may indicate HPV infection,should still receive HPV vaccination if they arein the appropriate age group (up to 45-years-old), since the vaccine may protect themagainst high-risk HPV types that they have notyet acquired. However, these women should betold that the vaccination will not cure them ofcurrent HPV infections and that it will not treatthe abnormal results of their Pap test.2

References1. Hildesheim A, Herrero R, Wacholder S, et al: Effect of Human

Papillomavirus 16/18 L1 Viruslike Particle Vaccine Among YoungWomen with Preexisting Infection: A Randomized Trial. JAMA 2007;298(7):743–753.

2. Centers for Disease Control and Prevention. FDA Licensure of BivalentHuman Papillomavirus Vaccine (HPV2, Cervarix) for Use in Females andUpdated HPV Vaccination Recommendations from the AdvisoryCommittee on Immunization Practices (ACIP). MMWR 2010;59(20):626–629.

Answered by:Dr. Victoria Davis


Experts on Call

When to Send Head Injuries to the ED

When do you send a head injury to the emergency room? I treated a 10-year-oldhockey player who was hit last night. There was no loss of consciousness, buthe vomited once last night and today. What criteria do you use for further evaluation, and when should you send a patient to emergency?Submitted by: M. Kotkas, MD, Calgary, Alberta

?Head injury or concussion may encompass a widespectrum of clinical features, from those with min-imal symptoms to those with significant amnesiaor a period of unconsciousness. The AmericanAcademy of Neurology grading system may beused to stratify such injuries. Loss of conscious-ness, Glasgow Coma Scale < 15 on initial assess-ment, focal neurological deficit, retrograde oranterograde amnesia, persistent headache, andvomiting or seizures after the injury are the indica-tors of a more severe head injury.1

A subset of patients may require referral to asecondary care centre and CT scan. Althoughthere was no loss of consciousness, a 10-year-old

hockey player with a head injury, who had twoepisodes of vomiting within 24 hours, should bereferred to the ED. The amended 2007 NationalInstitute for Health and Care Excellence guidelinesmay be used to help decide which patients needto be referred to a hospital ED following headinjury.2

References1. Rana AQ: A Synopsis of Neurological Emergencies. Authorhouse,

Bloomington, Indiana, 2009. 69–81.2. Ghosh R, Docherty E, Schickerling S, et al: Application of the 2007

NICE Guidelines in the Management of Pediatric Minor Head Injuriesin a UK Emergency Department. Emerg Med J 2012; 29(3):197–200.

Answered by:Dr. Abdul Qayyum Rana andMr. Mohammed A. Rana


Experts on Call

?In the setting of metastatic pancreatic cancer, therecently published Actions Concertées dans leCancers Colo-rectaux et Digestifs (ACCORD) 11trial reported a 4.3 month improvement in medianoverall survival with the use of the combinationregimen FOLFIRINOX (5-fluorouracil, leucovorin,irinotecan, oxaliplatin) versus gemcitabine in thefirst-line setting.1 ACCORD 11 was a Phase III clin-ical trial that randomized 342 patients withchemotherapy-naive, metastatic pancreatic can-cer to receive intravenous chemotherapy withFOLFIRINOX or gemcitabine. Inclusion criteriaincluded a good performance status (EasternCooperative Oncology Group performance statusscore of 0 or 1) and a serum bilirubin of less than1.5 times the upper limit of normal. The primaryendpoint of overall survival (OS) was met at thetime of a pre-planned interim analysis after 250patients were enrolled, with a median OS of 11.1months in patients receiving FOLFIRINOX versus6.8 months in patients receiving gemcitabine.Additionally, the objective response rate was high-er with FOLFIRINOX (31.6%, versus 9.4% withgemcitabine), as was the progression-free survivalof 6.4 versus 3.3 months. However, greater treat-ment-related toxicities were seen with theFOLFIRINOX regimen, including cytopenias,febrile neutropenia, sensory neuropathy, GI toxici-ty (e.g., vomiting, diarrhea), and fatigue.

Molecular-targeted therapies, including anti-EGFR agents (e.g., erlotinib, cetuximab) and theanti-angiogenic agent bevacizumab, have thus faryielded little to no additional benefit when incorpo-rated into standard treatment algorithms and,therefore, remain investigational.2–4

The FOLFOX regimen (5-fluorouracil, leucov-orin, oxaliplatin), which is commonly used inpatients with metastatic colorectal cancer, is alsosometimes used in patients with metastatic pan-creatic cancer, especially those with an elevatedserum bilirubin level despite stent placement.

References1. Conroy T, Desseigne F, Ychou M, et al: FOLFIRINOX versus Gemcitabine

for Metastatic Pancreatic Cancer. N Engl J Med 2011; 364(19):1817–1825.

2. Moore MJ, Goldstein D, Hamm J, et al: Erlotinib Plus GemcitabineCompared with Gemcitabine Alone in Patients with AdvancedPancreatic Cancer: A Phase III Trial of the National Cancer Institute ofCanada Clinical Trials Group. J Clin Oncol 2007; 25(15):1960–1966.

3. Philip PA, Benedetti J, Corless CL, et al: Phase III Study ComparingGemcitabine Plus Cetuximab Versus Gemcitabine in Patients withAdvanced Pancreatic Adenocarcinoma: Southwest Oncology Group-directed Intergroup Trial S0205. J Clin Oncol 2010; 28(22):3605–3610.

4. Van Cutsem E, Vervenne WL, Bennouna J, et al: Phase III Trial ofBevacizumab in Combination with Gemcitabine and Erlotinib inPatients with Metastatic Pancreatic Cancer. J Clin Oncol 2009; 27(13):2231–2237.

Answered by: Dr. Roger Y. Tsang

What newer therapies (e.g., chemotherapy, radiotherapy, etc.) are there for cancer of the pancreas?Submitted by: C.Y. Marks, MD, North York, Ontario

New Pancreatic Cancer Therapies


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Treating Nasal Septal Perforations

What is the current management of patients with nasal septal perforations?Submitted by: Gabriel Anid, MD, Thompson, Manitoba

Nasal septal perforations occur due to a varietyof causes. Some examples include:

• Traumatic causes (due to nose picking, facial trauma, motor vehicle accidents, etc.)

• Drugs (cocaine intake is a common etiology)• Iatrogenic causes (after surgical repair ofseptal deviation, septorhinoplasty, etc.)

• Granulomatous disease (Wegener’s, midlinelethal granuloma, etc.)

• Occuptional causes (chrome and platinumworkers)

If the perforation is asymptomatic, it may notrequire treatment. The treatment is obviously toavoid the causative agent. For occupational eti-ology, such as chrome plating, the use of per-sonal hygiene, masks, protective equipement,ointments applied to the nasal septum (lanolinand paraffin), and measures to modify the acidmist are all helpful.

Prefabricated septal buttons made from sili-con could be used and are usually placed underlocal anesthesia. Buttons may be used as short-term or long-term treatment. They are especiallyuseful if surgery is not advisable due to the ageof the patient, comorbid health problems, orother factors. However, septal buttons are occa-sionally poorly tolerated by certain individuals.

Various surgical techniques exist to close theperforation. An advancement flap (for small per-forations), a lower turbinate pedicled flap, andother mucoperichondrial or composite flaps haveall been used with variable success rates,depending on the size of the defect, the nature ofthe perforation, and the experience of the sur-geon. However, we must remember that anunsuccessful surgery will invariably result in alarger perforation.

Answered by:Dr. Ted Tewfik

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Mildly Elevated MCV and MCH

An inordinate number of CBCs I order seem tohave elevated MCV, and MCH is usually mildlyelevated. What is the necessary follow-up in otherwise healthy individuals?Submitted by: L. Kramer, MD, Brantford, Ontario

A patient with an elevated mean corpuscular volume, ormean cell volume (MCV), without anemia has an isolatedmacrocytosis, and a patient with an elevated MCV withanemia has a macrocytic anemia. Macrocytosis andmacrocytic anemia can be due to numerous causes, suchas vitamin B12 or folate deficiencies, medications thatimpair DNA synthesis, liver disease, alcohol misuse,hypothyroidism, reticulocytosis, or underlying bone marrowfailure states. Common causes of an isolated macrocytosisin an asymptomatic patient may be due to alcohol orunderlying fatty liver disease.

The mean corpuscular, or mean cell, hemoglobin (MCH)is the average mass of hemoglobin in each red blood cell.This is not particularly useful, as in macrocytosis the aver-age red blood cell is larger and contains a greater amountof hemoglobin than what would be expected. The work-upshould be focused on the causes of macrocytosis. A prop-er work-up and follow-up has to be made on a case-by-case basis and determined by the patient’s history andphysical exam.

Answered by:Dr. Cyrus Hsia


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Common Causes of Anosmia

What are the common causes of anosmia?Submitted by: Len Grbac, MD, Etobicoke, Ontario

The causes of anosmia, and/or hyposmia,include the following etiological factors:

• Congenital causes: Kallmann syndromeaffects 1:50,000 females and 1:10,000 males.Patients have delayed or absent puberty andan impaired sense of smell. At puberty, mostaffected individuals do not develop secondary sex characteristics, and affectedfemales usually have amenorrhea

• Nasal and/or sinus disease (nasal polyposis, sinusitis): In these cases, the useof local steroid sprays or surgical removal ofthe polyps brings back the sense of smell

• Upper respiratory infection: The anosmia orhyposmia is temporary and improves afterthe episode is gone due to the potentialregeneration of the olfactory epithelium.Recovery of smell and/or taste in thesecases can take weeks to months; however,rarely, the olfactory mucosa do not recover atall

• Endocrine anomalies: Such as hypothyroidism and diabetes mellitus, maycause neural degeneration of the olfactorysystem

• Drugs and environmental agents: Tobaccosmoking impairs the ability to identify odours

• Occupational exposure to chemicals: Mayalso lessen the sense of smell. This includeslead poisoning and drugs (such as amphetamines, estrogen, naphazoline, phenothiazines, prolonged use of nasaldecongestants, etc.)

• Medical intervention: Radiation therapy,nasal or sinus surgery, tracheotomy

• Frontal lobe tumour: In Foster Kennedy syndrome (meningioma or plasmacytoma,usually of the olfactory groove) there is opticatrophy of one eye, papilledema of the othereye, anosmia, and central scotoma

• Head trauma: Especially injury to the cribriform plate, where the olfactory fibresenter the nose

• Idiopathic causes

Vitamins, zinc, steroids (systemic or localspray), and tricyclic antidepressants have allbeen used to treat anosmia. However, the resultshave not been very favourable.

Answered by:Dr. Ted Tewfik


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Follow-up for Mole Biopsy Findings

What follow-up is recommended for a mole biopsy that demonstrates architectural dysplasia?Submitted by: Teresa Oliva-Custic, MD, Ottawa, Ontario

?Melanocytic nevi (moles) that demonstrate archi-tectural dysplasia histologically are often referredto as dysplastic nevi. Dysplastic nevus is a histo-logic diagnosis and not a clinical diagnosis.

Melanocytic nevi with architectural dysplasiaare often further subdivided by pathologistsaccording to whether mild, moderate, or severedysplasia is present in the biopsy.

It is important to know how an individualpathologist reports their nevi with architecturaldysplasia, as this can vary from pathologist topathologist. When in doubt, it is best to request are-examination of the histologic slide by a traineddermatopathologist.

Most melanocytic nevi with architectural dys-plasia are, in fact, benign, although there is con-troversy as to the potential for these nevi to devel-op into melanoma.

As melanocytic nevi with severe architecturaldysplasia can be difficult to distinguish frommelanoma in situ, it is best for these lesions to bere-excised with a 5 mm margin.

Follow-up of a melanocytic nevus with mild or moderate architectural dysplasia is more

controversial. Nevi with mild architectural dyspla-sia are almost always benign, and, if they areexcised with a 2 mm margin, no further treatmentis needed even if there is evidence of residualnevus at the excised margin. Nevi with moderatearchitectural dysplasia, if excised with a 2 mmmargin and clear margins, can be followed. If thereis residual nevus at the excised margin, it may bebest to re-excise the lesion with a 2 to 5 mm mar-gin even though the majority of these lesions arebenign, because, if they clinically recur, they canappear as “pseudomelanoma” a benign, histolog-ic simulator of true melanoma. These recur-rences can be problematic for dermatologists to diagnose.

If a patient has multiple atypical nevi (a clinicaldiagnosis), whether familial or sporadic, theyshould be followed regularly by a dermatologist,because they are likely at higher risk of melanomathan patients without multiple atypical nevi.

Answered by: Dr. Richard Haber


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Malaria Prophylaxis

What is the current recommendation with regards to malaria prophylaxis whentravelling to the Caribbean? What islands bear the most risk?Submitted by: Len Grbac, MD, Etobicoke, Ontario

?The malaria risk by geographic area and rec-ommendations for prophylaxis were lastrevised in 2009 by the Malaria Subcommitteeof the Committee to Advise on TropicalMedicine and Travel and are available on thePublic Health Agency of Canada’s website.1

In the Caribbean, malaria transmissionoccurs in Haiti. Malaria risk also exists in ruralareas of the Dominican Republic, with the high-est risk in provinces bordering Haiti; in addition,risk exists in all areas of La Altagracia Province,including resort areas. Malaria risk in Jamaicais very limited and exists in Kingston.Intermittently, rare cases of malaria are reported in Greater Exuma Island of theBahamas, but, because the risk is very limited,prophylaxis for travellers to this island is notrecommended.

For all Caribbean islands where malaria riskexists, chloroquine prophylaxis is recommend-ed. Chloroquine or hydroxychloroquine is takenonce weekly, beginning one week before enter-ing a chloroquine-sensitive malarial region, dur-ing the period of exposure, and for four weeksafter leaving the malarial region. For individualsunable to tolerate chloroquine or hydroxy-chloroquine, atovaquone/proguanil, doxycy-cline, or mefloquine should be used.

Reference1. Canadian Recommendations for the Prevention and Treatment of

Malaria Among International Travellers — 2009. www.phac-aspc.gc.ca/publicat/ccdr-rmtc/09vol35/35s1/index-eng.phpC.Accessed: January 18, 2013.


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Documents

Experts on Call1. Awad IA, Little JR, Akrawi WP, et al: Intracranial Dural Arteriovenous Malformations: Factors Predisposing to an Aggressive Neurological Course. J Neurosurg 1990;