P3580 - Cloaked Identity, Early T-Cell Precursor Lymphoblastic Leukemia (ETP-ALL) Masquerading as Autoimmune Pancreatitis

Award: Presidential Poster Award

Mahum Nadeem, MBBS¹, Shreya Garg, DO¹, Dan McEntire, MD², Bryce S. Hatfield, MD³, Ravi Vachhani, MD^3
1Virginia Commonwealth University Health System, Henrico, VA; ²Virginia Commonwealth University Medical Center, Richmond, VA; ³Virginia Commonwealth University Health System, Richmond, VA

Introduction: Early precursor T cell acute lymphoblastic leukemia (ETP-ALL) is rare, affecting about three per million annually, primarily males in their teens to early twenties. The classic presentation is lymphadenopathy (LAD) or a mediastinal mass. Abdominal involvement is rare and affects the liver and spleen. We report a case of a young male with abdominal LAD and recurrent acute pancreatitis secondary to leukemic infiltration mimicking autoimmune pancreatitis.

Case Description/Methods: A 35-year-old male with a history of two acute pancreatitis episodes in the past year presented with progressive abdominal pain and a 20-pound weight loss. Work-up was negative for gallstones, alcohol use, hypercalcemia, medications, or inflammatory bowel disease. Labs showed: AST 84 U/L, ALT 125 U/L, ALP 325 U/L, bilirubin 22.7 (direct 14.9) μmol/L, and normal lipase. CT revealed an enlarged pancreas with a 3.5 cm ill-defined mass in the head, causing biliary obstruction and abdominal LAD. MRI showed an edematous, sausage-shaped pancreas, suggesting autoimmune pancreatitis. He underwent ERCP and EUS with fine-needle biopsy of the pancreatic head, and placement of fully-covered metal stents (FCSEMS) in the common bile duct. Cytopathology showed benign pancreatic parenchyma with marked fibrosis and a dense lymphoplasmacytic infiltrate, predominantly lymphocytes, and few plasma cells; IgG4 staining was negative.

The patient was readmitted with worsening abdominal pain, fever, jaundice, and E. coli septicemia. Imaging raised concerns of acute cholecystitis, leading to FCSEMS exchange for plastic stents, to rule out any stent-related cystic duct occlusion. Persistent symptoms, abnormal liver enzymes, and leukocytosis resulted in a subtotal cholecystectomy and liver biopsy. Pathology revealed severe chronic cholecystitis and periportal inflammation, bile ductular proliferation, and mild steatosis. Despite negative IgG4 studies, due to high suspicion of autoimmune pancreatitis steroids were started with no improvement. Persistent leukocytosis prompted a peripheral smear and flow cytometry, revealing ETP-ALL. Based on this, a review of gallbladder, liver, and pancreas confirmed T-lymphoblastic leukemia/lymphoma infiltration in all specimens

Discussion: Acute pancreatitis is a rare presenting symptom of ETP-ALL. Despite convincing features of autoimmune pancreatitis, this case was a diagnostic challenge and underscores the importance of broad differential diagnosis especially when conventional treatments do not alleviate symptoms



Disclosures:


Mahum Nadeem, MBBS¹, Shreya Garg, DO¹, Dan McEntire, MD², Bryce S. Hatfield, MD³, Ravi Vachhani, MD³. P3580 - Cloaked Identity, Early T-Cell Precursor Lymphoblastic Leukemia (ETP-ALL) Masquerading as Autoimmune Pancreatitis, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.