Derm Cases · Dermatology / Procedural Dermatology
OSCE — elliptical excision design and disease-specific margins
An 8-minute OSCE on fusiform design, Breslow-based melanoma margins, low-risk BCC margins, and when to refer for Mohs.
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Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE on fusiform design, Breslow-based melanoma margins, low-risk BCC margins, and when to refer for Mohs.
Brief (to candidate)
Station: minor-operations counselling. Patient A has melanoma on the leg, Breslow 0.9 mm. Patient B (photo) has a well-defined BCC on the back. Patient C has recurrent BCC on the nasal ala. You have 8 minutes to plan margins and excision design.
[9]Candidate instructions
- Explain elliptical design (RSTL, ~3:1, layered closure).
- Give melanoma clinical margin for Breslow 0.9 mm.
- Give low-risk trunk BCC margin teaching figure.
- Explain why Patient C is not a simple tight ellipse.
- Distinguish clinical margin from histologic bread-loaf clearance.
Mark scheme (examiner)
| Domain | Marks | Expected points |
|---|---|---|
| Design | 2 | RSTL, ~3:1, dog-ear concept, layers |
| Melanoma | 2 | 1 cm for ≤1 mm Breslow |
| BCC low-risk | 2 | ~4 mm standard excision teaching |
| High-risk | 2 | Mohs/specialist for recurrent nasal infiltrative |
| Pathology concept | 2 | Bread-loaf ≠ 100% margin control |
Examiner notes
Fail if candidate offers destructive hyfrecation for melanoma scar or 2 mm margins for invasive melanoma.[1]
References6ShowHide
- [1]Swetter SM, Tsao H, Bichakjian CK, et al. Guidelines of care for the management of primary cutaneous melanoma. Journal of the American Academy of Dermatology, 2019.PMID 30392755
- [3]Peris K, Fargnoli MC, Garbe C, et al. Diagnosis and treatment of basal cell carcinoma: European consensus-based interdisciplinary guidelines. European Journal of Cancer, 2019.PMID 31288208
- [4]Stratigos A, Garbe C, Lebbe C, et al. Diagnosis and treatment of invasive squamous cell carcinoma of the skin: European consensus-based interdisciplinary guideline. European Journal of Cancer, 2015.PMID 26219687
- [5]Quazi SJ, Aslam N, Saleem H, et al. Surgical margin of excision in basal cell carcinoma: A systematic review of literature. Cureus, 2020.PMID 32821563
- [8]Hudson-Peacock MJ, Lawrence CM. Comparison of wound closure by means of dog ear repair and elliptical excision. Journal of the American Academy of Dermatology, 1995.PMID 7896954
- [9]Hanna S, Lo SN, Saw RP. Surgical excision margins in primary cutaneous melanoma: A systematic review and meta-analysis Eur J Surg Oncol, 2021.PMID 33722422