Somatostatinoma of the minor papilla treated by local excision in a patient with neurofibromatosis type 1.

Context: Somatostatinoma arising from the minor papilla in a patient with neurofibromatosis type 1 (NF1) is a known but very rare condition, which may cause non-specific symptoms and can present because of its mass effect.

Case report: A fifty-year-old female presenting with ongoing non-specific abdominal pain for a few months duration was found to have a mass involving the minor papilla. She had a history of NF1 but was otherwise well. Magnetic resonance imaging showed a dilated pancreatic duct and the finding of pancreatic divisum. The lesion was (18)fluorine-fluoro-2-deoxyglucose positron emission tomography/computed tomography and (68)gallium (Ga) DOTATATE negative. Endoscopic ultrasound revealed a 1.7 cm lesion confined to the minor ampulla. Endoscopic retrograde pancreatography attempts with biopsy and endoscopic ultrasound fine needle aspiration biopsy were inconclusive and resulted in mild pancreatitis on two occasions. Open local excision of the minor papilla was undertaken without complications. Histology confirmed a completely excised grade 1 neuroendocrine tumor with intense diffuse somatostatin staining.

Conclusion: Somatostatinoma of the minor papilla is a rare tumor that most commonly occurs in the setting of NF1 and may be amenable to local excision.