Periampullary GIST in a neurofibromatosis type 1 patient with idiopathic thrombocytopenic purpura - a rare case report at a tertiary care center in Bangladesh.

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the GI tract. GISTs in patients with neurofibromatosis type 1 (NF1) are relatively common, but periampullary GISTs associated with NF1 and idiopathic thrombocytopenic purpura (ITP) are exceedingly rare. This case report presents a unique and challenging instance of a periampullary GIST in a patient with NF1 and ITP, treated surgically with an uneventful recovery. Case presentation: A 40-year-old female with a known history of NF1 presented with epigastric pain, multiple café-au-lait spots, and cutaneous neurofibromas, along with thrombocytopenia. Contrast-enhanced computed tomography (CT) confirmed a lesion in the ampullary region, and histopathology of the endoscopic biopsy diagnosed a low-grade GIST. The patient was treated with steroids to correct ITP, followed by pancreaticoduodenectomy (PD) for complete surgical resection of the tumor. Discussion: Although periampullary GISTs in NF1 patients are rare, they can present with symptoms such as epigastric pain, GI bleeding, and jaundice. The diagnostic workup includes imaging studies such as CT and MRI, with confirmation achieved through histopathological examination and immunohistochemical staining. Surgical resection remains the mainstay of treatment for GISTs, with PD being the preferred approach for periampullary tumors. Conclusion: Periampullary GISTs in patients with NF1 and ITP are sporadic. This case highlights the importance of early detection and surgical intervention for GISTs, as well as the need for careful management of ITP to prevent complications during surgery and to implement effective strategies and solutions.