Recurrent melanoma presenting as a rash: a case report

TL;DR

A woman with melanoma developed a rash after T-VEC therapy, which was later confirmed as a rare recurrence of the cancer.

Contribution

This case report highlights an unusual presentation of melanoma recurrence as a rash rather than typical pigmented lesions.

Findings

A spreading erythematous rash on the left leg was found to be recurrent melanoma.

Skin biopsy confirmed recurrence with SOX10 and Melan-A positivity.

Imaging suggested multifocal disease recurrence in the left popliteal fossa.

Abstract

Melanoma is the most aggressive form of common skin cancer and recurrence, while rare, typically presents as pigmented papules or nodules near the primary site. Here, we describe a case of a woman with stage IIIC melanoma undergoing intralesional talimogene laherparepvec (T-VEC) therapy who developed a spreading erythematous rash on her left leg, accompanied by fatigue and leg swelling. Skin biopsy revealed recurrent melanoma, with SOX10 and Melan-A positivity, and imaging showed features concerning for multifocal disease recurrence in the left popliteal fossa. This case highlights an unusual presentation of melanoma recurrence and underscores the importance of biopsy in ­evaluating new skin findings in patients with a history of melanoma.

Melanoma often presents as a brown to black pigmented lesion with changes in size, shape or colour. Our study presents a unique case of recurrent melanoma presenting as a rash following a T-VEC injection.

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