a rare case of calf muscle metastasis from a non-functional pancreatic neuroendocrine carcinoma

pancreatic neuroendocrine tumors (pnet) are uncommon pancreatic neoplasms, accounting for 1-2% of all pancreatic tumors. however, they have a better prognosis and long-term survival compared to exocrine pancreatic cancer. pnets can be divided into functional or non-functional based upon whether or not they excrete active substances relevant to specific clinical syndromes. skeletal muscle metastasis is also a rare condition and differentiation between a primary soft tissue sarcoma and metastatic carcinoma is difficult without biopsy. thus, skeletal muscle metastases from pancreatic neoplasms are exceedingly rare, with only a few cases reported in the literature. we present a 34-year-old man with metastatic pancreatic neuroendocrine carcinoma that was initially thought to be a primary soft tissue tumor. pathology and immunohistochemistry demonstrated the tumor to be a metastasis from a pancreatic neuroendocrine carcinoma. a brief review of the literature on this subject is also presented.