S6005 A Rare Complication of Poorly Controlled Celiac Disease: Duodenal Obstruction Secondary to Combined B and T Cell Lymphoma

Introduction: Celiac disease carries an increased risk of lymphoproliferative disorders, particularly enteropathy-associated T-cell lymphoma (EATL) with a 50-fold increased risk. Diffuse large B-cell lymphoma (DLBCL) occurs at a 3-fold higher rate. Strict adherence to a gluten-free diet is crucial for reducing malignant complications. Case Description/Methods: A 62-year-old Spanish-speaking woman presented in 2011 with iron deficiency anemia (hemoglobin 10.3 g/dL), abdominal pain, and vitamin D deficiency. Anti-tissue transglutaminase and endomysial antibodies were positive. Esophagogastroduodenoscopy (EGD) demonstrated atrophic mucosa, blunted villi, and luminal narrowing in the duodenum. Pathology confirmed celiac disease (Marsh IIIC). Despite extensive counseling, she was lost to follow-up. Fourteen years later, without any interval follow-up, she presented with abdominal distension, nausea, and vomiting. She denied adhering to a gluten-free diet. Labs demonstrated worsening anemia (hemoglobin 6.8 g/dL), hypoalbuminemia (albumin 2.4 g/dL), and mild transaminase elevations (AST 55 U/L, ALT 110 U/L). Computed tomography revealed a 4.3 × 2.4 cm lobulated soft tissue lesion at the hepatic hilum extending distally with circumferential duodenal thickening, resulting in gastric outlet obstruction. Computed tomography also showed extensive lymphadenopathy. Esophagogastroduodenoscopy and endoscopic ultrasound (EUS) showed complete duodenal bulb obstruction with wall thickening and malignant-appearing porta hepatis lymph nodes. Duodenal and lymph node biopsies were positive for both T and B cell lymphomas. Immunohistochemistry revealed CD20-positive cells and CD3-positive T cells. After further pathologic evaluation and multidisciplinary discussion, she was diagnosed with DLBCL with a subset of T cell population secondary to T cell activation in the setting of long-standing, poorly controlled celiac disease. Bone marrow biopsy confirmed advanced-stage disease. With conservative management of the obstruction and initiation of inpatient chemotherapy, her duodenal stricture rapidly resolved, allowing her to resume enteral feeding within 1 week. Discussion: This case illustrates a rare malignant obstruction from combined DLBCL with T-cell activation in poorly controlled celiac disease. It underscores the importance of dietary adherence and regular follow-up in celiac patients to prevent malignant complications, as well as the diagnostic utility of EUS-guided tissue acquisition in complex lymphoproliferative disorders.