Merkel Cell Carcinoma: A Description of 11 Cases

Merkel cell carcinoma (MCC) is a malignant neuroendocrine tumor. Metastasis or lymph node spread is often detected at diagnosis. We performed a descriptive, retrospective study of patients diagnosed with MMC at Hospital Universitario Fundación Alcorcón in the Community of Madrid, Spain between January 1998 and December 2018. Eleven patients (7 men [63%] and 4 women [36%]; mean age, 77.6 years) were diagnosed with MCC during this 21-year period; 45% of patients had stage IIIB disease (pTNM) at diagnosis. All patients but one underwent local surgery, and lymphovascular invasion was detected in 7 cases. Eight patients received adjuvant therapy after surgery (radiation therapy in 5 cases and chemotherapy in 3). Six patients (54%) died of MCC (mean survival, 14.5 months). MCC is an uncommon malignant tumor with an annual incidence of around 0.18 to 0.41 cases per 100 000 inhabitants; this is similar to the rate of 0.29 to 0.32 cases per 100 000 inhabitants a year detected in our series. Results with avelumab, a drug recently approved for the treatment of metastatic MCC; have been promising.