From Cutaneous Necrosis to Septic Shock: An ICU Case of Pancreatico portal Fistula Complicating Necrotizing Acute Pancreatitis

BACKGROUND: Pancreaticoportal fistula is an exceptionally rare and potentially fatal vascular complication of necrotizing pancreatitis. Its clinical presentation can be atypical, leading to delayed diagnosis and management. CASE SUMMARY: A 58-year-old woman with no previous medical history was admitted for severe necrotizing acute pancreatitis (lipase > 3000 IU/L, CTSI 6) of initially undetermined etiology. After initial improvement, she developed painful erythematous nodules on both legs on day 34, which rapidly evolved into necrotic lesions. On day 48, she was readmitted in septic shock with multiple organ failure. Contrast-enhanced CT revealed peripancreatic collections, portal vein thrombosis, and a communication between the collection and the portal system, consistent with a pancreaticoportal fistula. Skin biopsy demonstrated septal and lobular panniculitis with adipocyte necrosis, multinucleated giant cells, and focal microcalcifications, supporting the diagnosis of pancreatic panniculitis in the appropriate clinical context. Endoscopic ultrasound-guided drainage, octreotide, anticoagulation, and targeted antibiotics led to rapid hemodynamic stabilization, regression of skin lesions, and normalization of laboratory parameters, allowing ICU discharge on day 85. CONCLUSIONS: This case illustrates a rare association between erythema nodosum-like lesions and pancreaticoportal fistula complicating necrotizing pancreatitis. The cutaneous presentation preceded the septic shock and was the key to the underlying diagnosis.