MBBS SAQ · dermatology
Keloid and Hypertrophic Scar — SAQ
Source-bounded short-answer question on diagnosis, biopsy, histology, treatment hierarchy and counselling for a symptomatic chest keloid.
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Questions
a) Give the most likely diagnosis and two defining clinical features. (2 marks)[1][3]
b) State when you would biopsy a scar-like lesion and give two histological differences between a keloid and a hypertrophic scar. (3 marks)[1][3][10]
c) Give a stepwise, evidence-bounded management plan, including the place of intralesional steroid, combination treatment and surgery/radiotherapy. (5 marks)[2][5][7][8][9]
d) State two counselling or follow-up points that must be documented. (2 marks)[1][2]
Model Answer
(a) Diagnosis and defining features — 2 marks
- Diagnosis: keloid. It extends beyond the original acne-scar boundary into adjacent skin and has persisted/progressed rather than flattening. The firm lobulated or pseudopodial morphology and itch/pain support the diagnosis.[1][3]
- Award 1 mark for the diagnosis and 0.5 mark for each of two defining features. Family history and chest site support susceptibility but do not replace the boundary test.[1][3]
(b) Biopsy and histology — 3 marks
Biopsy is not routine for a typical keloid. Biopsy when the diagnosis is uncertain or the lesion is ulcerated, fixed, destructive, unusually changing, unexplained by the clinical history, or otherwise suspicious for DFSP, scar-associated SCC, inflammatory disease or infection. A sufficiently deep sample and clinicopathological correlation are required.[1][3]
Keloid
Broad keloidal collagen
- Broad, glassy, hyalinised eosinophilic collagen bundles
- More haphazard or keloidal collagen pattern
Hypertrophic scar
Nodular myofibroblastic scar
- Relatively aligned or nodular collagen
- More evident myofibroblastic activity
Award 1 mark for an appropriate biopsy indication and 1 mark for each correctly contrasted histological feature. Histology cannot reconstruct the original wound boundary; that distinction remains clinical.[3][10]
(c) Stepwise management — 5 marks
- Agree the target and baseline (1 mark). Record pain, itch, function, lesion dimensions and photographs; explain that no treatment is a universal cure and comparative evidence is heterogeneous.[1][2]
- First-line treatment (1.5 marks). Silicone may be continued only on intact, epithelialised skin, with a low-certainty-benefit discussion. Offer intralesional triamcinolone for the symptomatic keloid. The 2024 KECORT e-Delphi preferred 40 mg/mL, four-week intervals and a maximum 80 mg per month, while finding no complete dosing consensus; individualise volume and counsel about pain, atrophy, telangiectasia and dyspigmentation.[4][5]
- Inadequate response (1 mark). Refer for an experienced scar service to consider combination intralesional therapy such as 5-fluorouracil, cryotherapy or another specialist option. Do not invent a universal mixture or interval. Laser is only an adjunct: a Cochrane review found low- or very-low-certainty evidence for most comparisons.[2][6]
- Surgery (0.75 mark). Excision alone has high recurrence because it creates a new wound. Operate only after agreeing the closure, adjuvant and follow-up plan; options include intralesional treatment, silicone/compression where feasible, or selected postoperative radiotherapy.[1][2]
- Radiotherapy (0.75 mark). This is a selected specialist option for recurrent/refractory adult keloids, not a universal “gold-standard” schedule. A meta-analysis reported 22% overall postoperative recurrence and heterogeneous modality subgroups; another meta-analysis did not show a significant timing advantage for immediate over delayed treatment. The radiation oncologist individualises modality, dose, fractionation, timing and shielding. Avoid during pregnancy and generally defer in children.[7][8][9]
(d) Counselling and follow-up — 2 marks
Award 1 mark each for any two well-explained points:[1][2][3]
- Treatment aims may be less pain/itch, improved function or flattening; complete eradication is not guaranteed.[1][2]
- Recurrence is common and study follow-up is inconsistent; review according to the active protocol and continue surveillance long enough to detect clinically meaningful recurrence.[2][7]
- Future optional trauma should be weighed against her personal scar history. If surgery is necessary, reduce wound tension and consider silicone only after complete epithelialisation.[3][4]
- Ask what matters to her, acknowledge distress and include pain, itch, sleep, function and body image in follow-up.[3]
Examiner's marking notes
- The defining phrase is “beyond the original wound boundary.”[1][3]
- A biopsy answer must distinguish a typical clinical diagnosis from an atypical lesion; “biopsy every keloid” is incorrect.[1][3]
- Full marks require a hierarchy, not an unranked treatment list.[2]
- Exact intralesional-steroid numbers must be identified as 2024 expert consensus, not universal law.[5]
- Do not award a fixed radiotherapy dose as the only correct regimen. The safe answer is specialist, individualized postoperative planning with explicit evidence uncertainty.[7][8][9]
References
- [1]Ekstein SF, Wyles SP, Moran SL, et al. Keloids: a review of therapeutic management Int J Dermatol, 2021.PMID 32905614
- [2]Walsh LA, Wu E, Pontes D, et al. Keloid treatments: an evidence-based systematic review of recent advances Syst Rev, 2023.PMID 36918908
- [3]Jeschke MG, Wood FM, Middelkoop E, et al. Scars Nat Rev Dis Primers, 2023.PMID 37973792
- [4]De Decker I, Hoeksema H, Verbelen J, et al. The use of fluid silicone gels in the prevention and treatment of hypertrophic scars: a systematic review and meta-analysis Burns, 2022.PMID 35367089
- [5]Yin Q, Wolkerstorfer A, Lapid O, et al. KECORT Study: An International e-Delphi Study on the Treatment of KEloids Using Intralesional CORTicosteroids in Clinical Practice Am J Clin Dermatol, 2024.PMID 39298112
- [6]Leszczynski R, da Silva CA, Pinto ACPN, et al. Laser therapy for treating hypertrophic and keloid scars Cochrane Database Syst Rev, 2022.PMID 36161591
- [7]Mankowski P, Kanevsky J, Tomlinson J, et al. Optimizing Radiotherapy for Keloids: A Meta-Analysis Systematic Review Comparing Recurrence Rates Between Different Radiation Modalities Ann Plast Surg, 2017.PMID 28177974
- [8]Hsieh CL, Chi KY, Lin WY, et al. Timing of Adjuvant Radiotherapy After Keloid Excision: A Systematic Review and Meta-Analysis Dermatol Surg, 2021.PMID 34417379
- [9]Liu EK, Cohen RF, Chiu ES Radiation therapy modalities for keloid management: A critical review J Plast Reconstr Aesthet Surg, 2022.PMID 35817711
- [10]Ogawa R Keloid and Hypertrophic Scars Are the Result of Chronic Inflammation in the Reticular Dermis Int J Mol Sci, 2017.PMID 28287424