Gastric Metastasis of Merkel Cell Carcinoma: Case Report

Merkel cell carcinoma (MCC) of skin is a rare tumorwith aggressive behavior. Local recurrences, regionallymph node and distant metastases of MCC are fre-quent but to date metastasis to upper gastrointestinaltract was reported only a few. We present a 75-year-old man who had primary MCC at his left thigh. Thetumor was excised and the patient was directed tolocal radiotherapy. He had developed abdominal andthoracal subcutaneous metastatic nodules within 5 and 8 months after surgical excision, respectively. Inthe tenth month, a second operation had to be per-formed because of a perforated duodenal ulcer andincidentally a submucosal yellow-white nodule mea-suring 2 cm in diameter was found in the wall of gastriccardia and excised. This lesion was histologically iden-tical to the primary tumor, hence, gastric metastasis ofMCC. The patient rejected further therapy and died17 months after the initial diagnosis. Differential diag-nosis of MCC and distinction of gastrointestinal MCCmetastasis from primary neuroendocrine tumors maybe difficult. Clinical information and histopathologicalfeatures along with the results of immunohistochemi-cal stainings are very important in this distinction.