A 55-year-old man presents with recurrent episodes of watery diarrhea (10 stools/day), abdominal pain, weight loss, and a skin rash described as erythematous, necrolytic, annular lesions predominantly on the perineum and lower extremities. Fasting glucose is 240 mg/dL (new onset DM). CT scan shows a 4 cm pancreatic tail mass with hepatic lesions. What is the diagnosis?

• A VIPoma (Verner-Morrison syndrome)
• B Carcinoid syndrome from ileal carcinoid
• C Somatostatinoma
• D Glucagonoma syndrome ✓

Explanation

Glucagonoma syndrome is characterized by the 4 D's: Dermatitis (necrolytic migratory erythema — NME, a blistering/crusting rash in periorificial, perineal, and lower extremity areas), Diabetes mellitus (from glucagon-induced insulin resistance and glycogenolysis), Diarrhea, and DVT (deep venous thrombosis). Glucagonoma is a rare alpha-cell pancreatic NET; most are malignant and metastatic at presentation. Serum glucagon levels are markedly elevated (>500 pg/mL). VIPoma causes profuse watery diarrhea with hypokalemia and achlorhydria (WDHA syndrome). Somatostatinoma causes diabetes, steatorrhea, and gallstones.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.