VOL 2 NO 11 DCMC Emergency Department Radiology Case of

VOL 2 NO 11 NOVEMBER 2015

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DCMC Emergency DepartmentRadiology Case of the MonthThese cases have been removed of identifying information and are intended for peerreview and educational purposes only.

Welcome to the DCMC Emergency Department Radiologycase of the month!

In conjunction with our pediatric radiologyspecialists from ARA we hope you enjoy these monthlyradiological highlights from the case files of the EmergencyDepartment at DCMC. These cases are meant to highlightimportant chief complaints, cases, and radiology findings thatwe all encounter every day.

If you enjoy these reviews we invite you check outPediatric Emergency Medicine Fellowship RadiologyRounds, which are currently offered quarterly and are heldwith the outstanding support of the pediatric radiologyspecialists at Austin Radiologic Association.

If you have any questions or feedback regarding the Case of the Month format, feel free to email Robert Vezzetti, MD at [email protected].

PEM Fellow Conference Schedule November 2015

4th - 9:15-10:15 Envenomations.........................Drs Earp and Berg 10:15-11:15 Failure to Thrive..........Drs Whitaker and Gardiner 11:15-12:15 ED Grand Rounds...............Dr Kurt Kleinschmidt

11th - 10:15-11:15 Bronchiolitis/Croup.......................................TBD 11:15-12:15 Asthma..........................Drs Wilkinson and Ryan 12:15-1:15 Bedside Teaching/Learning...Drs Allen and Ryan

13th - PEM Fellow Applicant Interview Day

18th - 9:15-10:15 M&M.................................Drs Gregg and Harrison 10:15-12:15 Board Review (Misc)................Dr Higginbotham 12:15 ED Staff Meeting

25th - THANKSGIVING HOLIDAY!

Guest Speaker: Dr Kurt Kleinschmidt, MD, FACEP, FACMTProfessor of Emergency Medicine, UT Southwestern Medical Director, Medical Toxicology

All Lectures are at Dell Children’s Medical Center in Command Rooms 3&4, unless otherwise specified.

Simulations are held at the CEC at University Medical Center - Brackenridge. Schedule subject to change.

This Month: PART I: Back pain in children! This is a symptom that is becoming more and more commonly seen in the Pediatric world (backpacks, etc) Most children have a sprain, contusion, or other benign entity, but, unfortunately, there are times when the etiology is not so benign.Our case this November is is child who has had several evaluations for back pain and limping until the diagnosis is made. It also highlights that, sometimes, history can be misleading.......

“docendo discimus”

In the original Roman calendar, November was the ninth month of the year. It got its name from the Latin word "novem" which means nine. However, it became the eleventh month when the Romans added in January and February to the start of the year.

This is the first part in a series

that we will be presenting on back pain and limping in children. Next

month, limping children. Stay tuned!

mailto:[email protected]




PAGE 2Lincoln’s Gettysburg address was given in November 1863. When organizers planned the ceremonial dedication of a cemetery for the Union dead on the Gettysburg battlefield, they didn’t choose the sitting president as the keynote speaker. That honor went to Edward Everett, a former Massachusetts senator, governor, Harvard president and U.S. secretary of state who was considered one of greatest orators of his day.

Case History:

A 2 year old male child, typically very active, is not as active these days. It seems that he has been complaining of limping for the past two weeks. Apparently, he was ridding in the stroller when he tried to wiggle his way out. He did so successfully, but in the process the somehow may have injured his foot. He was evaluated by an Urgent Care facility and, during the exam, it was difficult to tell if the pain was confined to the foot, or the leg, as when the child was allowed to walk, he did so with a limp, favoring the left leg/foot. There was also no evidence of erythema, edema, ecchymoses, or abrasion. He has good range of motion of the ankle, knee, and hip joints. Films were obtained which demonstrated no obvious abnormality (mom’s not sure what was imaged). He was diagnosed with a probable contusion, and his mother was advised to give Ibuprofen as needed for pain. He was also placed in a splint, as a growth plate fracture could not be excluded, and, since he was in pain, for comfort purposes as well. Followup with his Pediatrician was advised.

He followed up with his Pediatrician. At that time, the splint was removed (his mother thought he had been feeling better), and he was re-examined. During this exam, he was noted to continue to limp. Films were again obtained, which looked normal (again, mom was not sure what was imaged). His mother told the Pediatrician that she did not feel that the splint was helpful, so it was left off. Very careful observation and followup were ordered, with instructions to return immediately for any persistent or new symptoms.

During that week, he continued to limp and began to complain of back pain. The child was brought several more times for evaluation with his Pediatrician. Several days after his last visit, he began to refuse to ambulate at all. He was then referred to the Pediatric Emergency Department for evaluation.

On his evaluation in the ED, he appears uncomfortable. His vitals look normal and he is not (nor has been) febrile. His mother also reports that he has been “fussy” for the past few days, and not really himself. He indicates that his back hurts, which his mother has attributed to the child “suddenly throwing himself backwards” around a month ago while being held by his father, although he didn’t fall. His exam is remarkable for his refusing to stand and, when, well, forced to walk, he seems unsteady on his legs, limping a bit. He does not have any erythema, tenderness, or edema of his back, extremities or joints. Being a good clinician, you test his reflexes and strength of his extremities and they seem weaker in his lower extremities bilaterally.

Wow. Lots to consider here. Why won’t he walk? When he does, why does he seem so unsteady on his legs? Is it due to pain? If so, what is causing his discomfort? He’s had several imaging tests already...they failed to show an apparent cause of his symptoms. Does he need new images? If so, as we always ask, which tests would be appropriate for this patient?

Limping, Back Pain, Leg Pain: Clinician PainChildren who are limping and/or complaining of, or indicating, pain either in the back or legs have a broad differential. One good rule of thumb is not to dismiss these symptoms without considering more serious conditions. It is true that most of these symptoms can be attributed to strains, contusions, activity-related musculoskeletal etiologies. But back pain, especially in young children, or pain without a preceding trauma history, is especially concerning and should be investigated. Persistent pain, or the presence of neurologic symptoms, should be investigated even more carefully.

DCMC has a new website! If you are looking for back issues of the Newsletter, the easiest thing to do is type in the website search engine “DCMC Emergency Department Radiology Newsletters”. you’ll find what you’re looking for!


PAGE 3John F. Kennedy was assassinated in November 1963, some 52 years ago. While the youngest person ever elected president, he was not the youngest president; Theodore roosevelt was, who became president after william mckinley was assassinated in September of 1901.

Three towns in the U.S. take their name from the traditional Thanksgiving bird, including Turkey, Texas (pop. 465); Turkey Creek, Louisiana (pop. 363); and Turkey, North Carolina (pop. 270).

OK, the differential here is enormous, and there are certainly concerning physical examination findings, notably refusal to walk, probable persistent pain (including back pain), and now weakness on physical examination. One could obtain pelvis/femur/tib-fib films (which were likely done this past week) or image the back, which the mother states emphatically was not yet done. Of greater concern is the weakness on physical examination that is new, or at least was never noticed.

Back Pain Differential To ConsiderAcute Causes Muscle injury Herniated discs Fractures Discitis Osteomyelitis Epidural Abscess Spondyloarthropathies Urinary causes (stone, UTI, Pyelo)Chronic Causes Inflammatory Disorders Developmental (scoliosis, etc) Chronic Osteomyelitis Abscess Discitis Spondyloarthropathies

Limping Differential To ConsiderAcute Causes Fractures Contusions Sprains/Strains Discitis Osteomyelitis Myositis HSPChronic Causes Legg Calve Perthes Disease SCFE Joint infections Osteomyelitis Myositis Inflammatory arthropatiesBack pathology may present with limping, especially early in a disease course!

BEWARE OF:1. Night time pain2. Fever3. Pain in younger

children4. Pain without

history of trauma

5. weight loss6. weakness or

numbness7. incontinence

The easiest place to begin is at the beginning! You were able to contact both the Urgent Care and Pediatrician and discover that films of the pelvis, femur, tib-fib, ankle, and foot were all done and were all normal. So, you decide to image the back. Plain films are a good first step, but, admittedly, with the presence of bilateral leg weakness and decreased reflexes, more sophisticated studies may be needed.

Plain views of the lumbar-sacral spine are obtained. Looking at the films, there really is nothing remarkable here. The vertebral bodies are symmetric, the spinous processes appear normal; there is no evidence of fracture, spondylolysis, mass, cortex irregularities to suggest osteo, and the disc spaces look normal and symmetric as well. Now what?


PAGE 4November 30, 1835...Mark Twain’s Birthday. Born Samuel Langhorne Clemens, he grew up in Hannibal, Missouri. He is arguably one of the greatest American humorist and author, if not one of the most colorful. His birth coincided with a visit by Hallley’s Comet and he famously said he “would go out with it too”. He did, dying one day before the comet returned in 1910.

According to the Guinness Book of World Records, the largest pumpkin pie ever baked weighed 2,020 pounds and measured just over 12 feet long. It was baked on October 8, 2005 by the New Bremen Giant Pumpkin Growers in Ohio

Here are some hints for reading a lumbar spine:

Lateral View:

Coverage - The whole L-spine should be visible on both views

Alignment - Follow the corners of the vertebral bodies from one level to the next

Bones - Follow the cortical outline of each bone

Spacing - Disc spaces gradually increase in height from superior to inferior

AP View:

Alignment - The vertebral bodies and spinous processes are aligned

Bones - The vertebral bodies and pedicles are intact

Spacing - Gradually increasing disc height from superior to inferior. The pedicles gradually become wider apart from superior to inferior

So, applying the above guideline, the alingment is normal (red arrows), the dic spaces look normal and symmetric (yellow arrows), the pars interarticularis for all the vertebrae look normal (blue arrow).

So, normal plain films. The problem, though, is that there are a variety of pathological conditions that will be missed by plain films. Of greater concern is the weakness noted on this child’s physical exam. You decide to obtain some bloodwork while you contemplate your next move. Why the bloodwork? Well, if there is an inflammatory etiology to this child’s symptoms (ie osteo or myositis), then basic labs may be helpful. Of course, normal values do not rule out a serious condition, but may be reassuring and could potentially help narrow the broad differential. You obtain a CMP, CBC, ESR, CRP, and CK. They are all normal. The weakness is still an issue, your Spidey senses are tingling...you decide to obtain an MRI of the spine, with and without contrast.MRI is an excellent test to look for masses, inflammatory conditions (including infectious, such as osteo or discitis), spinal cord issues (such as cord edema or compression), and can provide greater detail regarding overall anatomy. One issue..this child will need sedation for the study.

Labs? What labs? Why?One other consideration is obtaining laboratory studies in limping children or children with back pain with no antecedent history of trauma or xrays that do not show an obvious source of the pain. A typical workup consists of CBC, ESR, CRP, CK. The thinking behind this is that, is these tests can be helpful in ruling out (or in) inflammatory conditions (infectious for example), or malignancies. Be warned, though, that there is not agreement as to what values are considered abnormal or what values can be used to reliably exclude more serious conditions. Laboratory results should be used in combination with history and physical examination findings.


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Here are selected MRI images for this patient. Needless to say, they are very concerning. The first noticeable finding is that T9 is compressed and abnormal compared to the other vertebrae (yellow arrow). Additionally, there is edema surrounding that vertebra, even extending to the cord space (purple arrow). Most concerning of all, however, is the presence of a mass (red arrow) causing all of the trouble. The MRI images of the cervical spine were normal.

OK, we have a probable cause of this child’s symptoms. Next steps?

This child needs admission to the hospital and further imaging. The working diagnosis includes, at this point, neuroblastoma, sarcomatous lesions, and other neuroblastic tumors. MRI scanning of his brain and chest are performed, in addition to laboratory testing.

This child was admitted to the Pediatric Intensive Care Unit after consultation with the Pediatric Intensivist, as well as Pediatric Hematology-Oncology, and Pediatric Neurosurgery. He underwent an MRI of the brain, of which selected images are seen here. The most notable finding is the presence of a mildly enhancing mass, seen in the posterior region of the right temporal lobe (blue arrow). There were also two smaller lesions in the right occipital and right frontal lobe. All of these lesions were thought to represent metastasis. An MRI of his chest was also obtained.

Tony Sarg, a children’s book illustrator and puppeteer, designed the first giant hot air balloons for the Macy’s Thanksgiving Day Parade in 1927. He later created the elaborate mechanically animated window displays that grace the façade of the New York store from Thanksgiving to Christmas.


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Snoopy has appeared as a giant balloon in the Macy’s Thanksgiving Day Parade more times than any other character in history. As the Flying Ace, Snoopy made his sixth appearance in the 2006 parade.

Here are selected images from the chest MRI study which demonstrate a large (9.4 x 5.4 x 9.6 cm) anterior mediastinal mass (red arrow). This large mass actually was displacing the esophagus posteriorly (yellow arrow) as well as displacing the thoracic trachea posteriorly (purple arrow). The mass is lobulated (green arrow) and heterogeneous, with enhancing septations (orange arrow). Internal organs (liver, heart, spleen, kidneys) are all normal. What could this mass be? While the differential is pondered, the child develops incontinence and flaccid paralysis of his bilateral lower extremities. He is immediately taken by Pediatric Neurosurgery for laminectomy and debulking of the mass, along with decompression of the spinal cord.

Recognize this diagram to the left? You should. In March (2015) we presented a case of a child with an mediastinal chest mass that was determined to be posterior in location and was diagnosed with a Ewing Sarcoma; there is a thorough review of chest masses in that issue.

Anterior mediastinal masses can often look like cardiomegaly on plain radiographs. To help determine if this is a mass or cardiomegaly, chest CT is often a first line study. Chest MRI is also a good test, but CT is better at differentiating lung parenchyma than MRI.

Courtesy: Radiologyassistant.nl

Cardiothoracic RatioRatio of: - maximal horizontal cardiac diameter - maximal horizontal thoracic diameter (inner edge of ribs / edge of pleura)A normal measurement should be less than 0.5.

One can use the cardiothoracic ratio to determine the presence of cardiomegaly


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REFERENCES1. Kim TY, Minasyan L, and Herman MI. Limping: Evaluation, Diagnosis, and Management in the Pediatric ED. Pediatr Emerg Med Prac. 2006:3(8).2. Levine MJ, McGuire KJ, McGowan KL, et al. Assessment of the test characteristics of C-reactive protein for septic arthritis in children. J Pediatr Orthop. 2003; 23(3):

373-7.3. Kayser R, Franke J, Mahlfeld K. Value of ultrasound diagnosis in Legg-Calve-Perthes disease. Schweiz Rundsch Med Prax. 2003;92(24):1123-7.4. Bernstein Rm and Cozen H. Evaluation of back pain in children and adolescent. Am Fam Physician. 2007;1;76(11):1699-1676.5. Postovsky S, Bialik V, Keider Z, et al. Large cell lymphoma of bone presented by limp. J Pediatr Orthop B. 2001; 10(1): 81-4.6. Barkin RM, Barkin SZ, Barkin AZ. The limping child. J Emerg Med. 2000;18(3):331-9.7. Moran CA, Suster S, and Koss MN. Primary germ cell tumors of the mediastinum: III. Yolk sac tumor, embryonal carcinoma, choriocarcinoma, and combined

nonteratomatous germ cell tumors of the mediastinum--a clinicopathologic and immunohistochemical study of 64 cases. Cancer. 1997;15;80(4):699-707.

Teaching Points:1. Beware of back pain in children, particularly young children or when there is an lack of a history of trauma.2. Physical examination findings that are especially concerning are persistent or worsening pain, fever, or any

neurological signs, such as weakness, incontinence, or numbness.3. The differential diagnosis of back pain and limping is broad. History is key when evaluating these patients.4. Plain radiographs are a reasonable way to being a radiological evaluation of a patient with back pain. Often,

obtaining images above and below where the suspected pain is at is suggested, as referred pain can cloud the clinical picture.

5. Limping children also should be approached with caution; often the pathology may be in the back or hip and not just the lower extremities. (more on this in Part II of this series!)

6. Basic laboratory investigation (CBC, ESR< CRP, CK) is a good, but not definitive, adjunct to the evaluation of a child with back pain. Normal labs, however, do not completely eliminate pathology and must be used in the clinical context of the child.

Case ResolutionAfter tumor debulking and decompression of the spinal cord, this child continued his stay in the Pediatric Intensive Care Unit for some time. Pediatric Hematology-Oncology was consulted, and, based on tumor pathology results, including genetic markers, he began chemotherapy with Etoposide, Aprepitant, and Cisplatin. After debulking he continued to have lower extremity flaccid paralysis; Pediatric Rehabilitation medicine was consulted in addition to Pediatric Urology, as the child developed neurogenic bladder. He was transferred out of the PICU to the Oncology floor and remains in treatment.

In addition to tumor debulking, IV Decadron was started before surgery (and continued thereafter); this helps to reduce inflammation and edema caused by tumor compression. the child had bone marrow studies and Immunostain testing done. The pathology determined that the mass was a Stage IV Metastatic Yolk Sac Tumor. Thankfully, the bone marrow and blood pathology tests were negative. His Immunostaining tests were positive for AE1/AE3, AFP, Vimentin, and S100. He also underwent and abdominal CT scan and was found not to have additional organ involvement.

Yolk sac tumors typically involve the testis/ovaries, but can occur in other locations (mediastinum), and are a type of germ cell tumor. Pure yolk sac tumors are the most common in children. It is theorized that hypermethylation of the RUNX3 gene promotor, which is involved in the differentiation of of the yolk sac endoderm. These tumors often present as painless testicular masses and metastasis is uncommon.

On imaging, these tumors are heterogenous. They are composed of cells that resemble embyronal structures. They are positive for AFP, and, in some patients, Vimentin. Remember, though, AFP can be positive in a variety of tumors.

These tumors are highly aggressive, but with treatment the survival rate is quite good.

These tumors have a honeycomb pattern on histiologic examination.

Here’s what these tumors look like on ultrasound (in this case a scrotal tumor); the image on the right is of a yolk sac tumor; on the left a normal ultrasound. The image on the right shows a hetergeneous mass that has completely replaced the right testicle. In these patient, orchiectomy is part of treatment, in addition to chemotherapy.

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VOL 2 NO 11 DCMC Emergency Department Radiology Case of