OSCE — non-healing keratotic nodule: cutaneous SCC risk features, biopsy and treatment pathway

Brief (to candidate)

A 72-year-old man on long-term immunosuppression after renal transplant presents with a tender, crusted, hyperkeratotic nodule on the lower lip that has enlarged over 3 months. He has extensive actinic damage on the face and hands. You have 8 minutes to assess risk, plan diagnosis and outline management.

Candidate instructions

1. Recognise suspected invasive cutaneous SCC and its precursors (AK, Bowen).
2. List high-risk features relevant to this case (lip, transplant, rapid growth).
3. Plan biopsy and staging concepts (AJCC / Brigham high-risk features).
4. Outline surgical management (margins vs Mohs) and when to image for perineural disease.
5. Address immunosuppression modification and field care.
6. Mention advanced options (radiotherapy, anti-PD-1) at high level.

Examiner checklist (mark each domain / 10)

Model key actions

• Treat progressive lip nodule in a transplant patient as high-risk SCC until proven otherwise.^[2]
• Biopsy promptly; plan margin-controlled surgery (often Mohs at lip) and nodal assessment.^[1][3]
• Coordinate immunosuppression strategy and field UV management with transplant/dermatology teams.^[2]

Common errors

• Prolonged observation of a non-healing keratotic nodule in an immunosuppressed host.
• Missing perineural red flags (pain, paraesthesia).
• Using only field creams for clearly invasive clinical disease.
• Ignoring transplant-specific risk (SCC:BCC ratio inversion, multiple primaries).
• Incomplete nodal examination and safety-net.