OSCE — Pilomatricoma (pilomatrixoma)

Brief (to candidate)

You will assess a patient with a presentation consistent with Pilomatricoma (pilomatrixoma).
You have 8 minutes to take a focused history, outline examination, investigations, and management including red flags.

Clinical context

Pilomatricoma is a common benign tumour of hair-matrix (matrical) cells in children, presenting as a firm, stony-hard, calcified, deep-seated subcutaneous nodule on the face, neck or upper extremities. Histology: basaloid (matrical) cells + ghost (shadow) cells + calcification. Driven by activating CTNNB1 (beta-catenin) mutations. Treatment is surgical excision. Multiple pilomatricomas flag associated disease — examine for Gardner syndrome (FAP), myotonic dystrophy, Turner syndrome, Kabuki syndrome and constitutional mismatch repair deficiency.^[2]

Candidate tasks

1. Clarify onset, severity, associated features, and red-flag symptoms.
2. State focused examination priorities.
3. List first-line investigations and any named score/criteria.
4. Give immediate resuscitation steps.
5. Outline definitive management with doses/routes where standard.
6. Name complications and disposition (ward / HDU / theatre / discharge safety-net).
7. Mention one special-population modifier (pregnancy, child, elderly, CKD).

Examiner checklist

Model outline

Lead with the working diagnosis and life threats. Resuscitate before definitive tests when unstable. Use guideline-standard therapy with named agents and doses. Document escalation criteria and follow-up. A safe candidate is specific, structured, and never delays critical care for non-urgent imaging.^[1]