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Staging and treatment of Merkel cell carcinoma

Patricia Tai, MB, BS, DABR, FRCR, FRCPC
Section Editors
Robert S Stern, MD
June K Robinson, MD
Michael B Atkins, MD
Deputy Editor
Michael E Ross, MD


Merkel cell carcinoma (MCC) of the skin is a rare, aggressive cutaneous malignancy that predominantly affects elderly Caucasians and has a propensity for local recurrence and regional lymph node metastases. Other terms used to describe this tumor include neuroendocrine or primary small cell carcinoma of the skin, trabecular cell carcinoma, and anaplastic cancer of the skin.

The staging and treatment of MCC are discussed here. The clinical features and initial diagnosis of MCC are reviewed separately. (See "Pathogenesis, clinical features, and diagnosis of Merkel cell (neuroendocrine) carcinoma".)


The eighth (2017) edition of the tumor, node, metastasis (TNM) staging system provides important information for both management and prognosis of patients with Merkel cell carcinoma (MCC). The TNM system is recommended by both the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) and is presented in detail in the tables (table 1 and table 2) [1]. In contrast to the seventh TNM staging system, the eighth edition has separate criteria for clinical and pathological staging.

Based upon the TNM information, patients are assigned to prognostic stage groups. These can be summarized as follows:

Stage I – Primary tumors ≤2 cm maximum tumor dimension, without evidence of regional lymph node involvement.

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Literature review current through: Nov 2017. | This topic last updated: Jun 26, 2017.
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