Pancreatic PEComa: Case Report of an Extremely Rare Tumor.

Pancreatic perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms with only a few reported cases. Their non-specific clinical presentations and imaging features often lead to misdiagnosis. We report a case of a 63-year-old female with intermittent left upper quadrant pain. Imaging revealed a hypervascular mass in the pancreatic tail, initially suspected to be a neuroendocrine tumor. The patient underwent distal pancreatectomy with splenectomy. Histopathological examination showed that the tumor consisted of epithelioid and spindle cells with clear cytoplasm, a rich vascular network and low mitotic activity. Immunohistochemically, the tumor cells were positive for HMB-45, Melan-A, and smooth muscle actin, confirming the diagnosis of pancreatic PEComa. The postoperative course was uneventful. Given the uncertain malignant potential of PEComas, complete surgical excision is the preferred treatment option, with long-term follow-up recommended. This case highlights the diagnostic challenges of pancreatic PEComas and underscores the role of histopathology and immunohistochemistry in their accurate identification and management.