Spontaneous Regression of Merkel Cell Carcinoma: Case Report

Abstract

Merkel cell carcinoma (MCC) is a rare skin neuroendocrine tumor presumably arising from Merkel cells in the basal layer of epidermis. It is an aggressive tumor predominantly found on the head and neck area of elderly people, with a mortality rate around 41% for all stages. Complete spontaneous regression of MCC is seldom observed, mostly in elderly women. We describe complete spontaneous regression of large, histologically confirmed MCC in an elderly woman after biopsy, which occurred incidentally, while waiting for radical surgery with skin flap. Next-generation sequencing with SOPHiA Solid Tumor Plus Solution did not reveal any relevant gene mutations or rearrangements. An update of literature for these very rare cases is provided.

Cytokeratin-20 negative nodal Merkel cell carcinoma with regressed primary: a potential pitfall in interpretation of nodal metastasis

“…It was first described by O'Rourke et. al in 1986 [6], with around 60 additional cases reported since then [7][8][9][10][11][12]. Spontaneous regression could explain the reported cases of MCC involving lymph nodes without a primary skin tumor [13][14][15][16][17].…”

18F-FDG and 18F-AIF-NOTA-Octreotide PET/CT Confirmed a Rare Case of Cutaneous Merkel Cell Carcinoma With a Solitary Local Nodal Metastasis

“…MCC is a rare aggressive neuroendocrine tumor (NET), which usually presents with local lymph node involvement 1–4 . The possible reasons are that the primary lesion may have spontaneously regressed, or the tumor arises de novo from neural cells located within the involved lymph nodes 5–7 . 18 F-FDG PET/CT imaging showed good performance for the detection of MCC 8,9 .…”