Rare Presentation of Leiomyoma of the Pancreas.

Leiomyomas are benign neoplasms that originate from smooth muscle cells and most commonly occur in soft tissues, the gastrointestinal tract, and the uterus. Leiomyomas of the pancreas are exceptionally rare, with, to our knowledge, only 6 documented cases prior to this report. This case was also challenging because of the young age of the patient and an atypical initial presentation. A 21-year-old male presented with progressive jaundice and severe anemia. Contrast-enhanced computed tomography revealed a heterogeneously hyperenhancing mass in the arterial phase in the head of the pancreas with a double-duct sign. Endoscopic biliary drainage was performed, followed by endoscopic biopsy that revealed a mesenchymal tumor; leiomyoma was confirmed with an immunohistochemical evaluation. The patient underwent pancreaticoduodenectomy, and the histopathologic and immunohistochemical examinations of the resected specimen confirmed the diagnosis of a low-grade leiomyoma arising from the ampulla of Vater. This case not only highlights the rarity of pancreatic leiomyomas and the potential for atypical presentation but also emphasizes the importance of considering leiomyoma in the differential diagnosis, even in young patients, and supports surgical resection as the preferred treatment approach.