Pancreatic Resection for Metastatic Melanoma Originating from the Nasal Cavity: A Case Report and Literature Review

Metastatic pancreatic malignant melanoma is considered to be a highly aggressive neoplasm, and only few metastasectomies for lesions originating from the skin or the ocular region have been reported. We report a case of resection of pancreatic metastasis of malignant melanoma originating from the nasal cavity. An isolated pancreatic tumor was detected in a 46-year-old man who had undergone proton-beam therapy for nasal melanoma 12 months earlier. He underwent distal pancreatectomy with splenectomy and the pathological diagnosis was metastatic malignant melanoma. We review cases of malignant melanoma metastatic to the pancreas and further discuss their incidence, therapeutic strategy, and outcome of mucosal melanoma of the head and neck. Metastatic pancreatic tumors clinically account for fewer than 2% of all pancreatic malignancies (1, 2), and potentially resectable metastasis to the pancreas comprises 1.5-3.0% of all cases of pancreatic resection for neoplasms (2-4). Pancreatic metastases are often detected during follow-up of the primary lesion. The operative indication may differ between primary cancer and metastasis. According to a review of 243 patients with resected metastatic pancreatic tumors, the sites of origin were renal cell cancer (61.7%), colorectal cancer (7.8%), melanoma (4.9%), sarcoma (4.9%), lung cancer (3.3%), gastric cancer (3.3%), gall bladder cancer (3.3%), and breast cancer (2.5%) (1). A few decades ago, resection was usually not considered to be indicated for metastatic melanoma of the pancreas, because of multiple organ involvement and high morbidity and mortality after pancreatic surgery, but recent advances in diagnostic modalities and surgical techniques have made it acceptable. Surgical metastasectomy has the unique potential to cure the cancer or even provide palliation, whereas systemic chemotherapy for malignant melanoma only modestly improves survival. The indication for metastasectomy is limited to cases with a fair general condition, good disease control of the primary lesion, an isolated pancreatic tumor, and findings on imaging studies indicating resectable tumor. The original sites for malignant melanomas are mostly the skin of the head, neck, and lower extremities due to their frequent exposure to sunlight; however, malignant melanoma can occur in various mucosal sites where pigment cells are present. The etiopathogenesis, incidence, and clinical behavior of mucosal melanoma are considered to be different from those of skin melanoma. We present a case of pancreatic resection for metastatic melanoma originating from the nasal cavity and discuss clinical- and treatment-related issues of the condition.