Clincal Reasoning - Melanoma

Year 2 OSCE Practice 2011 Set 2, Clinical Reasoning Station

Candidate Instructions

The patient in the next room is Earl, who is 66 years old. He has presented reluctantly to your practice after pressure from his wife who thinks she has noticed a change in one of the moles on his back over the past few months. You have been given this patient’s past medical history. You are not expected to ask any further history from this patient

You have 8 minutes to discuss with the examiner three (3) differential diagnoses, these should be the most likely diagnoses.

You should include at least two (2) positive and two (2) negative features of this history, other than those listed above, which support or refute your diagnoses.

You should expect the examiner to ask questions around your reasoning.

TASKS

Differential diagnoses with reasoning – 8 minutes


History of Presenting Complaint

Earl -‐ a 66 year old male.

Occupation – Dairy farmer.

Social Hx – Lives with wife on farm in small town 3 hrs West of Toowoomba. 2 sons and 1 daughter, all adults and living several hours away, good relationship – frequently visit.

Drug/alcohol – smoker – 40 pack year Hx. Drinks carton of beer every 2 weeks. Nil recreational drugs

Presenting complaint – Wife noticed change in mole on back over past 2-‐3/12.

Story

Always had lot of moles since childhood. Several weeks ago wife mentioned possible change in mole on back. Not sure if mole was long standing or new, had never noticed before. Felt mole was getting darker and possibly bigger. Earl has not noticed anything, resistant to go see Dr. States “I have dozens of the things Doc, had them for years, I don’t think this is any different” Has not noticed any pain or itching of mole. Has had no recent temperatures or sweats. As not complained of any weight loss. Very active and busy on farm, some concerns with getting more tired and finding the work harder, puts this down to “getting old”. Has had several skin lesions excised in the past, most have come back as solar elastoses and IEC. 2 lesions returned as low grade SCC and one BCC. Had a course of Efudex (5-‐fluorouracil) cream for Rx of sun damage on face ~10 years ago – completed course but did not like it due to pain and discomfort. Has worked on dairy farm entire life except 2 years of National Service at age 20 where he was sent to Vietnam. Rarely, if ever, wears sunscreen though usually wears hat outdoors. He completed high school education to Grade 10 before beginning work on the farm. He is still very active on the farm and gets a lot of physical activity though his work. He feels his diet is good, his wife usually cooks and he claims to get his 5 vegetables and 2 fruit/ day. He has had his vaccinations from his national service, and a tetanus booster after a dirty cut ~ 15 years ago. He has not been overseas except for his national service and a visit to family in England ~10 years ago. Both parents are deceased, mother died of breast cancer at age 70 and father of lung metastases from an unknown primary at age 69. Has one brother who is in good health at age 70.


General Health

He feels his general health is good, he is active and not often sick.

Inspection

Generally well looking elderly male in o obvious distress. Pale skin with multiple naevi distributed across face, arms and torso. Extensive solar skin damage over face and arms.

Lesion

Pigmented, papular lesion, firm to palpation. Diameter = 6x10mm


Past Medical History:

Multiple skin lesions excised: solar elastoses, SCC and BCC.

HTN -‐ 2001

Obstetric History

N/A

Meds

Telmesartan

Allergies /ADR’s

Nil known

Past Surgical History:

Appendicectomy aged 8 yrs old

Immunizations :

From national service

Tetanus booster -‐ 1996

Family History:

Both parents deceased:

Mother – age 70 Breast ca

Father – age 69 lung mets, unknown primary.

Lifestyle

Smoking 20/day 40 pack year Hx

Alcohol carton full strength beer/2 weeks

Diet normal

Exercise good

Hobbies fishing

Pets 2 dogs, lots of cattle

Demographics

Occupation

Dairy farmer

Living arrangements

lives at home on rural farm with wife

Family

3 adult children, 1 older brother.


Instructions to Examiners

The patient in the next room is Earl, who is 66 years old. He has presented reluctantly to your practice after pressure from his wife who thinks she has noticed a change in one of the moles on his back over the past few months. The candidate has been given this patients history.

The candidate has 8 minutes to discuss 3 differential diagnoses, including positive and negative features of this history which support or refute their diagnoses.

Conduct of this station

• Ensure the candidate understands the tasks he/she has to do.

• The candidate is expected to discuss 3 possible differential diagnoses-‐ citing at least two (2) positive and two (2) negative points in the patient’s history, other than those listed above, that support or refute their choices.

• They are expected to have a balanced reasoning, and have prioritised the most likely diagnoses.

• They should be able to justify their reasoning with questions, if required-‐ they are expecting some questioning from the examiners.

If the candidates appear to have chosen an unlikely diagnosis-‐ please ask them to justify their choice.

Prompting the candidate for another diagnosis is permitted to allow them opportunity to discuss a more likely diagnosis.

TASKS

Differential diagnoses with reasoning – 8 minutes


Differential Diagnoses

1. Superficial Spreading Melanoma

Positive

• Change in pigmented lesion

• Hx of fair skin and multiple naevi

• Hx of extensive sun exposure/damage and minimal protection

• Hx of previous skin cancers

• Possible family Hx in father.

• Lesion asymmetry, irregular border, variegated colour, diameter > 6mm.

Negative

• Unsure if lesion new or long standing

• Has not noticed change himself

• No pain/itching or systemic symptoms

2. Nodular Melanoma

Positive

• As above.

Negative

• As above.

• Non-‐nodular pattern of growth

3. Dysplastic Naevi

Positive

• As above

• No systemic symptoms.

Negative

• As above

• No other dysplastic naevi

• Potential family Hx of melanoma.


4. Seborrheic keratosis

Positive

• Rapid growth over past 2-‐3 months.


Negative

• No itching

• Has not noticed change himself

• Lesion does not appear hyperkeratinised

5. Pigmented Basal Cell Carcinoma

Positive


• Hx of solar damage and previous BCC

Negative

• Significant atypical appearance

• Lack of typical BCC architecture

• Rapid growth/change.

6. Traumatised naevus

Positive

• Hx of multiple naevi

• Atypical appearance – darkening (haemorrhage into lesion)

Negative

• Painless lesion

• No Hx of trauma to naevus given.

• Suspicious of melanoma.


MARKING

Examiners are asked to grade student’s performance on a scale of 0 -‐ 4 in the areas on the mark sheet in capitals. The standards for awarding these grades are;

0 = Unequivocal fail: Student was unable to demonstrate history or examination skills without significant prompting, OR displayed unethical or unprofessional behaviour.

1 = Marginal fail: Student lacked a comprehensive approach, and/or needed considerable prompting to complete the task.

2 = Borderline pass: Student performed a systematic examination or history but did not complete some components in a number of areas of the marking guide.

3 = Clear pass: Student had a systematic approach, required little or no prompting, was confident and completed most components of the marking guide.

4 = High pass: Student had a high level of proficiency, well above what would be expected of a student in Year 2.

Examiners are required to make an overall judgement about the student’s performance in each area on the marking sheet. The specific items listed are there to remind examiners about issues which might be considered. It is not intended that these items should rigidly translate into a score.

It would be helpful, particularly when feedback is being given to poorly performing students, if there is some notation in the comments column. Also examiners may find it helpful, when considering what grade to award, to have indicated in the comments column when items were omitted or when prompting was required.

Global Score. This mark does not form part of the student’s overall mark. The score should reflect the student’s empathy and overall performance, and is from the examiner’s perspective only.


Pass Mark = 15/20 Pass/ Fail (Circle as appropriate) Comments (essential if the candidate has failed the station) Global Impression-‐ from examiners only-‐ score 0-‐4

Feature Comment Score (please circle)

General

Organised summaries of diagnoses

Appropriate diagnoses chosen

Prioritises diagnoses

Clear communication for presentation

0 1 2 3 4

Differential diagnosis ONE 0 1 2 3 4

Most likely and reasonable diagnosis

Appropriate supportive points

Appropriate negative points

Differential diagnosis TWO 0 1 2 3 4

Reasonable diagnosis

Appropriate supportive points

Appropriate negative points

Differential diagnosis THREE 0 1 2 3 4

Reasonable diagnosis Appropriate supportive points Appropriate negative points

Adequate Reasoning 0 1 2 3 4

Balanced reasoning

Shows understanding of diagnostic signs with questioning

Documents

Clincal Reasoning - Melanoma