Gastroduodenal Perforation Secondary to Heterotopic Pancreas in a Patient With Systemic Amyloidosis and End-Stage Renal Disease on Hemodialysis: A Case Report.

Heterotopic pancreas (HP) is a rare congenital anomaly characterized by pancreatic tissue lacking anatomical and vascular continuity with the orthotopic pancreas. Although usually asymptomatic and incidentally diagnosed, HP may rarely become clinically significant due to inflammation, ulceration, bleeding, obstruction, or gastrointestinal perforation. Systemic conditions such as amyloidosis, chronic kidney disease (CKD), and chronic hemodialysis may further increase gastrointestinal vulnerability through vascular fragility, impaired mucosal healing, and recurrent splanchnic hypoperfusion. We present the case of a patient with systemic amyloidosis and end-stage CKD on maintenance hemodialysis through a recently created brachial-basilic arteriovenous fistula who developed progressive gastrointestinal symptoms followed by acute abdomen. Initial manifestations included nausea and projectile vomiting one day after fistula creation, followed by progressive right upper quadrant abdominal pain radiating to the lumbar region, semiliquid bowel movements, dehydration, and hemodynamic instability. Imaging studies suggested a perforated viscus with intra-abdominal inflammatory changes. Emergency exploratory laparotomy revealed perforation at the antro-duodenal junction with diffuse fibrinous peritonitis and multiple cystic peritoneal lesions suspicious for malignant disease. Surgical management consisted of segmental gastroduodenal resection, extensive peritoneal lavage, targeted peritoneal biopsies, cholecystectomy, and appendectomy. Histopathological examination demonstrated heterotopic pancreatic tissue associated with ulceration and perforation. Immunohistochemistry of the peritoneal lesions showed positivity for WT1 and calretinin, consistent with benign peritoneal inclusion cysts. This case highlights an exceptionally rare cause of gastrointestinal perforation and underscores the importance of integrating clinical evolution, systemic comorbidities, intraoperative findings, pathology, and immunohistochemistry into surgical decision-making. The coexistence of amyloidosis, CKD, and hemodialysis-related hypoperfusion likely contributed synergistically to mucosal vulnerability and perforation.