Context It is uncommon to find cancer metastasizes to the pancreas; in fact less than 2% of pancreatic lesions represent metastatic disease. If metastatic disease to the pancreas is found, it is usually renal cell carcinoma, breast cancer, lung cancer or colon cancer. It is unusual for melanoma to metastasize to the pancreas, but if it does it is usually in the setting of widespread disease. Malignant melanomas very rarely develop isolated pancreatic metastasis. In fact, there have only been a few reported cases in the last 30 years of isolated metastatic melanoma to the pancreas. Case Report We report a unique presentation of an extremely rare diagnosis of isolated metastatic melanoma to the tail of the pancreas with unknown primary lesion. This patient presented with abdominal pain 8 years after having a curative Mohs procedure done for cheek melanoma. Abdominal imaging revealed a pancreatic tail mass. EUS-guided FNA of the pancreatic mass revealed a diagnosis of metastatic melanoma based on cytology and clinical history. Conclusions Accurate diagnosis of a pancreatic lesion or mass is critical because prognosis, survival, and management are all affected. In order to diagnose pancreatic lesions, effective sampling and immunocytochemistry is required. In this particular case, EUS-guided fine needle aspiration of the pancreatic mass allowed for an immediate diagnosis of metastatic melanoma based on cytology and clinical history. This highlights the importance and utility of EUSguided fine needle aspiration in distinguishing between a pancreatic metastatic lesion versus primary pancreatic cancer.
Minesh Mehta, Endashaw Omer