Reactive Spindle Cell Nodule in the Pancreas Post Fine Needle Aspiration: A Case Report and Literature Review.

Reactive spindle cell nodules (RSCNs) that occur after fine needle aspiration (FNA) are commonly documented in the literature. They are benign proliferation of spindle cells with some mitotic figures and nuclear pleomorphism that arise after tissue injuries like FNA. These lesions are non-capsulated and surrounded by parenchyma of organ tissue. Although RSCNs after FNA can occur in various organs of the body, there is a lack of well-established studies describing their presence in the pancreas. We present a case of a 74-year-old female treated with pancreatectomy for intraductal papillary mucinous neoplasm (IPMN), and RSCNs were found incidentally during post-surgery microscopic evaluation. This lesion showed similar characteristic microscopic features of the RSCNs found at different anatomical sites. To the best of our knowledge, this may be the first case of RSCNs after FNA into the pancreatic. This case expands the diagnostic framework of pancreatic spindle cell tumors.