Abstract
Merkel cell carcinoma (MCC) is a rare and typically aggressive form of skin cancer. It most commonly affects the elderly and has a predilection for the sun-exposed skin of the head and neck region. Other etiological factors include immune suppression, organ transplantation, and polyoma virus infection. MCC has a propensity to spread to regional lymphatics with a high locoregional recurrence rate. Since its discovery in 1972, treatment paradigms have shifted, with no consensus on optimal management strategies. Currently, standard of care includes surgical intervention to the primary and locoregional site with adjuvant radiotherapy for high-risk disease. In this paper, we discuss the history, pathology, and epidemiology of this rare disease with a focus on the evidentiary basis of treatment protocols. The use of sentinel lymph node biopsy as a management option will be the focus of this paper.
Highlights
Merkel cell carcinoma (MCC) is a rare and aggressive neoplasia first described in 1972 by Toker [1]
The discovery of neurosecretory granules in three of the original tumours studied by electon microscopy raised the possibility of a neuroendocrine source, and the MC was proposed as the cellular origin [3]
Sentinel lymph node biopsy can help to identify the presence of occult metastatic disease which can have prognostic implications
Summary
Merkel cell carcinoma (MCC) is a rare and aggressive neoplasia first described in 1972 by Toker [1]. CK20 is an intermediate filament protein that has been proposed as the most robust cytokeratin marker for distinguishing MCC from small-cell lung carcinoma and other cutaneous carcinomas [6]. Another biomarker used to differentiate these two carcinomas is thyroid transcription factor-1 (TTF-1). Despite the prominence of immunohistochemistry in the diagnostic workup of MCC, the College of American Pathologists released their 2010 recommendations in the pathological reporting of MCC of the skin These include type of procedure, tumour site/size, margins, lymphovascular invasion, invasion of deeper soft tissues, and lymph node status (Figure 2)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
