Testicular Metastasis of Merkel’s Cell Carcinoma

Abstract

Merkel cell carcinoma (MCC) in an uncommon neuroendocrine neoplasia that originates in the skin in which testicular metastasis is
atypical. There are only eight cases reported to date. A 65-year-old patient with a history of MCC in the right thigh who had been
treated in 2015 with surgery, chemotherapy and radiation therapy; presented to hospital with pain and right testicular enlargement
of one-month duration and with normal testicular tumor markers. An ultrasound study confirmed multiple hypoechoic nodular solid lesions compatible with neoplasia and orchiectomy was subsequently performed. The histological examination reported an
immunohistochemical pattern compatible with a diagnosis of MCC. The patient received adjuvant immunotherapy with Avelumab.
MCC rarely spreads to the testicle and, due to the shortage of studies, the best treatment of testicular metastasis remains uncertain;
however, immunotherapy may be appropriate.