A rare case of metastatic solitary fibrous tumor of the pancreas manifesting as a cystic neoplasm: a case report

Abstract

Background Solitary fibrous tumor (SFT) is a rare mesenchymal tumor that typically arises from the pleura. Although it may appear in other organs, it rarely develops in the pancreas. We report herein a rare case of metastatic SFT of the pancreas originating from an intracranial tumor and subsequently identified as a cystic neoplasm of the pancreas. Case presentation A 58-year-old woman with a past medical history of brain tumor visited the hospital for further investigation of a cystic tumor in the pancreas tail. Abdominal imaging showed a heterogeneously enhancing mass that was initially suspected as a neuroendocrine neoplasm, solid pseudopapillary neoplasm, or mucinous cystic neoplasm of the pancreas. Distal pancreatectomy was performed without any intraoperative and postoperative complications. Pathological findings confirmed a diagnosis of malignant SFT of the pancreas with hyperproliferative potential. A histopathological review of her brain tumor revealed that the pancreatic tumor was derived from her brain lesion. The patient developed recurrent brain disease 4 years after the pancreatectomy, but no recurrence has been observed in the abdominal cavity. Conclusions SFT should be considered in the differential diagnosis of untypical hypervascular pancreatic mass, particularly in patients with a history of an intrathoracic or intracranial mesenchymal tumor. Immunohistochemical analysis is crucial in detecting this tumor entity. Hyperproliferative status indicates a malignant disease and requires careful postoperative observation.

Pancreatic hamartoma: detection of harbouring NAB2::STAT6 fusion gene

“…Although most tumour lesions in the pancreas are epithelial tumours, non‐epithelial, mesenchymal tumours develop in rare cases and there are reports of solitary fibrous tumours (SFTs) 19–34 . An SFT is a fibroblastic tumour characterised by the prominent, branching, thin‐walled, dilated (staghorn) vasculature and NAB2::STAT6 gene rearrangement 35,36 .…”

“…1 Although most tumour lesions in the pancreas are epithelial tumours, non-epithelial, mesenchymal tumours develop in rare cases and there are reports of solitary fibrous tumours (SFTs). [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] An SFT is a fibroblastic tumour characterised by the prominent, branching, thin-walled, dilated (staghorn) vasculature and NAB2::STAT6 gene rearrangement. 35,36 Although SFTs are known to develop in the pleura and soft tissues, SFTs with a morphology resembling pancreatic hamartomas have been reported.…”

Imaging, pathology, and diagnosis of solitary fibrous tumor of the pancreas: a literature review

“…In this case, CT showed no enhancement in the arterial phase and heterogeneous enhancement in the venous area. We believe that it should be distinguished from neuroendocrine tumors, which show enhanced CT from the arterial phase to the portal venous phase [13,37], which makes it di cult for us to distinguish the disease, so many scholars before us also misdiagnosed it before surgery [1,10,11,13,26]. At the same time, we believe that it should also be differentiated from pancreatic cancer and solid pseudopapillary tumor of the pancreas.…”

“…The immunohistochemical differential diagnosis of SFT of the pancreas should include spindle cell tumors such as Gastrointestinal stromal tumor (GIST), smooth muscle sarcoma, nerve sheath tumor, brous mucinous sarcoma, perivascular epithelioid cell tumor, and vascular tumors [3,16,20,37]. The immunomarkers of SFT of the pancreas include STAT6, CD34, bc1-2, vimentin, and CD99 [34].…”

Cytopathological characteristics of solitary fibrous tumour involving the pancreas by fine needle aspiration: Making an accurate preoperative diagnosis in an uncommon location

“…Spindle cell lesions involving the pancreas can be diagnostically challenging due to their rarity, tumour heterogeneity, and morphological overlap with many disease processes, including non‐neoplastic diseases (chronic pancreatitis), as well as mesenchymal neoplasms, such as a gastrointestinal stromal tumour (GIST) and schwannoma. Reports of SFT of the pancreas are mainly limited to case reports and many provide limited details on the salient pathological features, pearls, and pitfalls 6,10,18,20,28‐30 . Furthermore, there are limited descriptions of the cytopathological features and key diagnostic work‐up for FNA of SFT of the pancreas.…”