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Collision of subungual melanoma and subungual squamous cell carcinoma: a case series

Boespflug A, Debarbieux S, Depaepe L, Chouvet B, Maucort-Boulch D, Dalle S1, Balme B, Thomas L. J Am Acad Dermatol. 2017 Sep 22. pii: S0190-9622(17)32443-X. doi: 10.1016/j.jaad.2017.09.038.

ABSTRACT

BACKGROUND:Subungual squamous cell carcinoma (SSCC) and subungual melanoma (SUM) are rare tumors. Several case reports of collision of a SSCC with a SUM (SSCC-SUM) have been published.OBJECTIVE:We sought to document clinical, dermoscopic and histological features in a case series of SSCC-SUM and describe their relative frequency compared to SSCC and SUM.

METHODS:All patients that underwent a surgical exploration of the nail apparatus with a dermato-pathological examination, from 2012 to 2015, were reviewed retrospectively to identify all cases of SSCC, SUM and SSCC-SUM. In patients with a SSCC-SUM, clinical characteristics were obtained from electronic medical records. All histological specimens were reviewed by three dermato-pathologists.

RESULTS:456 patients were reviewed. 78 patients were diagnosed with a SSCC (17% n=78/456), 63 patients were diagnosed with a SUM (14% n=63/456), and 9 patients were diagnosed with a SSCC-SUM. Patients with an SSCC-SUM represent 11% (n=9/78) of patients diagnosed with a SSCC and 14% (n=9/63) of patients diagnosed with a SUM.

LIMITATIONS:This was a single-institution retrospective study.

CONCLUSION:The association of a SSCC and a SUM is relatively frequent in patients with a SUM and warrants further consideration to understand the underlying mechanisms involved.Copyright © 2017. Published by Elsevier Inc.

KEYWORDS:SSCC; SUM; collision; confocal microscopy; dermatopathology; dermoscopy; squamomelanocytic tumor; subungual epidermoid carcinoma; subungual melanoma; subungual squamous cell carcinoma

PMID: 28947295 

DOI: 10.1016/j.jaad.2017.09.038

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