Are Solitary Fibrous Tumors of the Pancreas the Same Tumor as Pancreatic Hamartomas?

Abstract

This article describes the analysis of 9 cases and a literature review of solitary fibrous tumors (SFTs) of the pancreas. 1 The study showed that STAT6 is a useful marker for diagnosing SFTs in pancreatic tumors. Nuclear STAT6 expression was observed in 7 of the 8 examined SFTs. In addition, the presence of tumor cells intermixed with entrapped pancreatic parenchyma, along with the alternating cellularity and the presence of staghorn-like vessels, was identified as a helpful feature for diagnosing pancreatic SFTs.The authors mentioned desmoid tumor/fibromatosis, inflammatory myofibroblastic tumors, schwannomas, gastrointestinal stromal tumors, leiomyomas, melanomas, well-differentiated pancreatic neuroendocrine tumors, and sclerosing epithelioid mesenchymal tumors. However, pancreatic hamartoma, which was not mentioned in the paper, is another important differential diagnosis of SFT of the pancreas. 2-4 Pancreatic hamartoma is a rare tumor (or tumorlike lesion) characterized by mature acini and small-sized to medium-sized ducts with a distorted architecture, often accompanied by various amounts of fibrous stroma. 2 Interestingly, a recent study showed that pancreatic hamartomas frequently express STAT6 nuclear protein by immunohistochemistry and