Gastric Metastasis Of Merkel Cell Carcinoma: Case Report

Merkel cell carcinoma (MCC) of skin is a rare tumor with aggressive behavior. Local recurrences, regional lymph node and distant metastases of MCC are frequent but to date metastasis to upper gastrointestinal tract was reported only a few. We present a 75-yearold man who had primary MCC at his left thigh. The tumor was excised and the patient was directed to local radiotherapy. He had developed abdominal and thoracal subcutaneous metastatic nodules within 5 and 8 months after surgical excision, respectively. In the tenth month, a second operation had to be performed because of a perforated duodenal ulcer and incidentally a submucosal yellow-white nodule measuring 2 cm in diameter was found in the wall of gastric cardia and excised. This lesion was histologically identical to the primary tumor, hence, gastric metastasis of MCC. The patient rejected further therapy and died 17 months after the initial diagnosis. Differential diagnosis of MCC and distinction of gastrointestinal MCC metastasis from primary neuroendocrine tumors may be difficult. Clinical information and histopathological features along with the results of immunohistochemical stainings are very important in this distinction. Derinin Merkel hucreli karsinomu (MHK) agresif davranisli, nadir bir tumordur. Merkel hucreli karsinomun lokal rekurrensleri, bolgesel lenf nodu ve uzak metastazlari sik olmakla birlikte bildirilen ust gastrointestinal metastaz oldukca azdir. Yetmis bes yasindaki erkek hasta, sol bacagindaki MHK eksize edildikten sonra lokal radyoterapiye yonlendirilmistir. Tumor eksizyonundan sonraki 5. ayda karinda, 8. ayda toraks duvarinda subkutan metastatik noduller gelismistir. Ilk operasyondan 10 ay sonra perfore duodenal ulser nedeniyle yapilan ikinci operasyon sirasinda rastlantisal olarak midede, kardia duvarinda farkedilen 2 cm capli, sari-beyaz renkli, submukozal nodul eksize edilmistir. Bu lezyon MHKa#39;un mide metastazi tanisi almistir. Hasta daha ileri bir tedaviyi reddetmis ve baslangictaki tanidan 17 ay sonra yasamini yitirmistir. MHKa#39;un ayirici tanisi ile gastrointestinal MHK metastazlarinin primer noroendokrin tumorlerden ayrimi zorluk yaratabilir. Bu tur tani sorunlarinin cozumunde klinik bilgi, histopatolojik ozellikler ve immunohistokimyasal calismalar oldukca onemlidir.