Successful Treatment of Multiple Post-Operative Keratoacanthomas with Topical 5-Fluorouracil

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Nelson Ugwu
Nour Kibbi


keratoacanthoma, 5-fluorouracil, topical 5-FU


Keratoacanthomas (KAs) are fast-growing tumors and can be difficult to distinguish from squamous cell carcinomas (SCCs). Most KAs are sporadic, but KAs may also arise following traumatic procedures. We report the case of a 94-year-old male who developed multiple KAs following surgical excision of an SCC on the right lower extremity. The patient declined additional procedures including biopsy, surgery, or intralesional therapy. He was started on 5% topical FU using a 2 week on, 2 week off regimen for 16 weeks with resolution of disease. No recurrence was noted at 13 months. Topical 5-FU is a conservative, non-invasive treatment for post-traumatic KAs that is particularly suitable in the elderly, in whom the risks and morbidity from surgical or other non-invasive approaches are worth considering.


1. Chitwood K, Etzkorn J, Cohen G. Topical and intralesional treatment of nonmelanoma skin cancer: efficacy and cost comparisons. Dermatol Surg. 2013;39(9):1306-1316.

2. Goldberg LH, Silapunt S, Beyrau KK, Peterson SR, Friedman PM, Alam M. Keratoacanthoma as a postoperative complication of skin cancer excision. J Am Acad Dermatol. 2004;50(5):753-758.

3. Clark MA, Guitart J, Gerami P, Marks BR, Amin S, Yoo SS. Eruptive keratoacanthomatous atypical squamous proliferations (KASPs) arising in skin graft sites. JAAD Case Rep. 2015;1(5):274-276.

4. Gewirtzman A, Meirson DH, Rabinovitz H. Eruptive keratoacanthomas following carbon dioxide laser resurfacing. Dermatol Surg. 1999;25(8):666-668.

5. Pattee SF, Silvis NG. Keratoacanthoma developing in sites of previous trauma: a report of two cases and review of the literature. J Am Acad Dermatol. 2003;48(2 Suppl):S35-38.

6. Manalo IF, Lowe MC, Nelson KC, Chen SC. Triple therapy with intralesional 5-fluorouracil, chemowraps, and acitretin: A well-tolerated option for treatment of widespread cutaneous squamous cell carcinomas on the legs. JAAD Case Rep. 2019;5(12):1051-1054.

7. Silva E, Estebanez A, Martin JM, Monteagudo C, Montesinos E. Keratoacanthoma centrifugum marginatum after photodynamic therapy with good response to oral retinoids and topical 5-fluorouracil. Dermatol Ther. 2019;32(4):e12988.

8. Grupper C. Treatment of keratoacanthomas by local applications of the 5-fluorouracil (5-FU) ointment. Dermatologica. 1970;140:Suppl 1:127+.

9. Goette DK, Odom RB, Arrott JW, Diakon NC, Horn RT, Jr. Treatment of keratoacanthoma with topical application of fluorouracil. Arch Dermatol. 1982;118(5):309-311.

10. Singal A, Mohanty S, Bhattacharya SN, Baruah MC, Singh N. Unusual multiple keratoacanthoma in a child successfully treated with 5-fluorouracil. J Dermatol. 1997;24(8):546-548.

11. Thompson BJ, Ravits M, Silvers DN. Clinical efficacy of short contact topical 5-Fluorouracil in the treatment of keratoacanthomas: a retrospective analysis. J Clin Aesthet Dermatol. 2014;7(11):35-37.

12. Gray RJ, Meland NB. Topical 5-fluorouracil as primary therapy for keratoacanthoma. Ann Plast Surg. 2000;44(1):82-85.