Severe pancreatic exocrine insufficiency presenting with hypoalbuminemia, anasarca, and pulmonary edema in a patient with prior gastrectomy and suspected immunoglobulin G4-related pancreatobiliary disease.

A 55-year-old man with prior subtotal gastrectomy was admitted with generalized edema, 16-kg weight gain, dyspnea, and frequent watery pale stools. Laboratory tests revealed severe hypoalbuminemia (1.0 g/dL), anemia, elevated myogenic enzymes, liver dysfunction, and markedly decreased pancreatic enzyme levels. Computed tomography showed bilateral pleural effusion, pulmonary edema, ascites, diffuse soft tissue edema, and marked pancreatic atrophy. Stool Sudan III staining was positive, and urinary para-aminobenzoic acid excretion was reduced. Although cardiac, renal, and hepatic disorders were considered, they did not adequately explain the presentation. Pancreatic exocrine insufficiency was diagnosed. Serum immunoglobulin G4 was elevated at 199 mg/dL, and previous imaging showed poor visualization of the hilar bile duct, gallbladder wall thickening, and gallbladder atrophy. Therefore, possible immunoglobulin G4-related pancreatobiliary disease was considered the leading possible etiology of pancreatic atrophy and exocrine insufficiency, with prior gastrectomy as a modifying factor. Treatment with albumin, diuretics, and pancrelipase (1,800 mg/day) rapidly improved the overall condition of the patient. This case highlights that pancreatic exocrine insufficiency can present with severe third-space fluid shift, pulmonary edema, and compartment syndrome-like findings, highlighting the need to assess multifactorial causes.