Pancreatic PEComa: Case Report of an Extremely Rare Tumor

TL;DR

This paper reports a rare case of pancreatic PEComa, a tumor that is difficult to diagnose and requires histopathology and immunohistochemistry for confirmation.

Contribution

The contribution is a detailed case report of a rare pancreatic tumor with insights into its diagnostic challenges and management.

Findings

The tumor was confirmed as pancreatic PEComa through histopathology and immunohistochemistry.

Complete surgical excision is recommended due to the uncertain malignant potential of PEComas.

Accurate diagnosis requires combining imaging with histopathological and immunohistochemical analysis.

Abstract

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.

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