Mesentery lymphoma in a patient with Crohn's disease: An extremely rare entity.

INTRODUCTION: Lymphoma is a rare complication of long-standing Crohn's disease. We report a rare case of a diffuse, B-cell non-Hodgkin's lymphoma of the mesentery in a patient receiving treatment for Crohn's disease. PRESENTATION OF CASE: A 52 year-old patient presented with abdominal pain, anorexia and postprandial fullness. Abdominal examination revealed a firm mass, extending from the epigastrium to the right iliac fossa. CT scan showed a large intra-abdominal mass with air-fluid levels within, and soft tissue density along its walls, surrounded by distended bowel loops. The patient was scheduled for surgery due to clinical assumption of an intra-abdominal abscess. At laparotomy an ill-defined, lobulated mass with cystic areas was noted rising from the mesentery. Frozen section biopsy of the cystic mass revealed a non-Hodgkin follicle center B-cell lymphoma of the mesentery. DISCUSSION: To the best of our knowledge, this is an extremely rare case of lymphoma development in the mesentery, in a patient receiving treatment for Crohn's disease. Although the development of abdominal lymphomas can be justified as a possible consequence of the chronic immune-modulating therapy, their location can lead to diagnostic pitfalls.
CONCLUSION: Although mesentery has scarcely been presented as a potential site of occurrence of abdominal lymphomas in the process of treatment of inflammatory bowel diseases, this rare entity should be considered in the differential diagnosis of intra-abdominal lymphomas in patients with inflammatory bowel disease. In cases where imaging techniques do not provide definitive answers, surgical intervention can safely pose the accurate diagnosis.