Variability of Leser-Trélat Sign Secondary to Melanoma In Situ

Abstract

Leser-Trélat sign (LTS) is characterized as an eruptive display of multiple seborrheic keratoses (SKs) in association with malignancy. This case highlights the variable presentation of LTS secondary to melanoma. To our knowledge, this LTS pattern is the first case where the sign manifests as a subtle pattern secondary to melanoma. This stands in contrast to the five documented cases in the literature of LTS-melanoma, which exhibited distinctive and eruptive patterns. A 64-year-old Caucasian female presented for a wellness examination. No personal history of skin cancer was noted. Patient displayed an onset proliferation of SKs with an irregular, sub-centimeter macular nevus over her right lateral mid back. A 6mm punch biopsy was significant for melanoma in situ, arising within a lentiginous compound dysplastic nevus, focally abutting one peripheral tissue edge. A re-excision with a minimum of 5mm margins was completed and the specimen was negative for residual in situ melanoma. Because of the rare occurrence of this delicate pattern at the site of the melanoma, this presentation adds to the knowledge surrounding this diagnosis. This case emphasizes the importance of maintaining vigilance regarding skin manifestations associated with disease and highlights the critical importance of observation and identification of subtle physical exam findings.

Keywords: cutaneous malignancy; leser-trélat sign; melanoma; seborrheic keratoses; variability.

Figure 1. 6mm punch biopsy, positive for in situ malignant melanoma

Figure 2. Re-excision with minimum of 5mm margins was completed one week later

Specimen was found to be negative for residual in situ malignant melanoma