A Rare Cause of Chronic Diarrhea and Weight Loss

Abstract

A78-year-old woman was evaluated for fatigue, unintentional weight loss of 38 pounds, and diarrhea over the past year. She appeared in no acute distress. Her blood pressure was 120/80 mm Hg and her heart rate was 76 beats/min. She was 61 inches tall and weighed 96 pounds, with a body mass index of 18 kg/m. An abdominal examination was significant for mild epigastric tenderness to palpation. The patient would have approximately 7 nonbloody watery bowel movements during the day with occasional nocturnal diarrhea. Her bowel movements were not affected by fasting. She had associated lower abdominal pain and intermittent epigastric pain. Prior work-up included negative stool studies for Clostridium difficile, ova and parasites, culture, and Gram stain. Laboratory studies showed a normal hemoglobin level, mean corpuscular volume, thyroid-stimulating hormone level, alanine aminotransferase level, total bilirubin level, albumin level, and C-reactive protein level. She had an abnormal alkaline phosphatase level of 130 IU/L (38–126 IU/L), an aspartate aminotransferase level of 52 IU/L (15–41 IU/L), a g-glutamyl transpeptidase level of 49 IU/L (<41 IU/L), and a lipase level of less than 3 U (15–70 U/L). A colonoscopy and upper endoscopy showed no gross or histologic evidence of malignancy, celiac disease, or microscopic colitis. A contrast-enhanced computed tomographic scan of the abdomen and pelvis showed cirrhosis, an obstructing distal pancreatic duct calculus, and complete fatty replacement of the pancreas, which was highly suggestive of lipomatous pseudohypertrophy (Figure A). An endoscopic ultrasound was performed and confirmed the diagnosis and excluded an underlying pancreatic adenocarcinoma (Figure B). The patient denied alcohol use. Viral hepatitis serologies, iron saturation level, ceruloplasmin level, autoimmune serologies, and a-1 antitrypsin level all were normal. The most likely etiology of the patient’s cirrhosis was nonalcoholic steatohepatitis. The patient denied previous episodes of pancreatitis, but the presumptive etiology of the distal pancreatic duct calculus was chronic pancreatitis. Pancreatic enzyme replacement therapywas initiated and the patient reported resolution of her symptoms 2 days later. At our patient’s follow-up visit 1 month after initiation of pancreatic enzyme replacement therapy, her weight increased to 101 pounds and her symptoms resolved. Lipomatous pseudohypertrophy is a rare idiopathic clinical entity that has been described only in case reports and case series. Based on a small case series and literature review, Altinel et al determined that this condition occurs with equal frequency in males and females, with approximately 70% of cases diffusely involving the pancreas. Histologically, adipose pseudotumor replacement of pancreatic exocrine tissue is seen. Because of its low prevalence, the etiology of lipomatous pseudohypertrophy has yet to be determined. Varying presentations have been described including large pancreatic tumors subsequently diagnosed as lipomatous