Frantz Tumor (Solid Pseudopapillary Neoplasm) Mimicking an Infected Pancreatic Pseudocyst: A Case Report.

Frantz tumor, or solid pseudopapillary neoplasm (SPN), is a rare pancreatic tumor of low malignant potential that predominantly affects young women. Its clinical presentation is often nonspecific, and the differential diagnosis from other cystic pancreatic lesions, such as pseudocysts, represents a significant challenge. We report the case of a 31-year-old previously healthy woman who presented with abdominal pain, initially diagnosed and treated as an infected pancreatic pseudocyst. Following the initial surgical intervention and antibiotic therapy, the persistence of imaging findings and subsequent histopathological results led to the definitive diagnosis of a Frantz tumor. The patient subsequently underwent a curative-intent pancreatoduodenectomy. This case highlights the difficulty in distinguishing cystic pancreatic lesions. The patient's initial presentation, with a large fluid collection, gas foci, and elevated inflammatory markers, strongly suggested an infectious process, such as a complicated pseudocyst. Only histopathological examination of the surgical specimen enabled the correct diagnosis of the underlying neoplasm. SPN may show cystic and hemorrhagic degeneration, mimicking other lesions. Frantz tumor should be considered in the differential diagnosis of cystic pancreatic lesions in young women, even when the initial presentation suggests an inflammatory or infectious process. Histopathological confirmation is essential for proper management, which consists of complete surgical resection and is associated with an excellent prognosis.