Surgically resected pancreatic metastasis from nasal malignant melanoma: case report and literature review.

A 13-mm mass was observed in the pancreatic head of a 70-year-old woman who had undergone melanoma resection in the nasal cavity 10 years earlier. Endoscopic ultrasonography (EUS) showed that the mass consisted of multiple hypoechoic nodules. EUS-guided fine needle aspiration and pancreatic juice cytologies revealed neoplastic cells positive for HMB45 and melan-A staining with a few melanin granules, indicating the presence of a metastatic malignant melanoma. These additional stainings were evaluated after surgery. In the surgically resected specimen, the mass had multiple nodule-like structures, some of which were brown colored. Immunocytochemistry and electronic microscopy findings confirmed the diagnosis of malignant melanoma. Microscopic findings were similar to the nasal specimen; therefore, the pancreatic lesion was considered to be a metastasis from the nasal cavity.