Fistulizing Crohn’s Disease Complicated by Hidden Retroperitoneal Abscess: A Case Report and Review of the Literature

Abstract

Crohn's Disease (CD) is a chronic inflammatory disorder of the intestinal tract characterized by trans-mural damage of the bowel wall often complicated by strictures, entero-visceral and perianal fistulae and abscesses. Both computed tomography and magnetic resonance enable clear visualization of the involved intestinal tract together with various extra-and intraintestinal complications. Herewith, the uncommon case of a hidden retroperitoneal abscess with para-vertebral collection, as a consequence of a penetrating CD of the terminal ileum, is described. Retrofascial collections, due to fistulizing CD, are rare events often misdiagnosed or even recognized late in the clinical course and associated with severe and potentially lifethreatening consequences. Prompt assessment with cross-sectional imaging is necessary. MR imaging is being more frequently used in the follow-up of CD since the lack of ionizing radiations which avoids any biological impact in these patients. CAsE REPoRtA 30-year-old female with a 3-year history of Crohn's Disease (CD) of the terminal ileum and complaining recently of a 3-week progressive abdominal pain, nausea and diarrhea (5-6 bowel movements/day) was admitted to the hospital. The patient was febrile (37.5 °C) and presented right lumbar pain radiating to the gluteus region. The patient had been treated with methotrexate, mesalazine and metronidazole over the previous 6 months.Upon presentation, the abdominal examination revealed normal bowel sounds and abdominal tenderness without rebound. A mass, 7 cm by 3 cm, was palpated in the lower right quadrant, which was tender to palpation, without guarding, rebound or tap tenderness. The remainder of the examination was normal. Blood tests showed moderate leucocytosis and an increase both in Erythrocyte Sedimentation Rate (ESR) and C-reactive protein (CRP) levels