An Unusual Presentation of Primary B-cell Lymphoma of the Small Bowel in an Immunosuppressant-Naive Patient With Newly Diagnosed Crohn's Disease.

Inflammatory bowel disease (IBD) consists of two primary conditions: ulcerative colitis (UC) and Crohn's disease (CD). UC primarily impacts the colon, leading to inflammation of the mucosal layer. Conversely, CD involves transmural inflammation and can affect any segment of the gastrointestinal tract, ranging from the oral cavity to the perianal region. Patients with CD can have symptoms for many years prior to diagnosis, or they may present acutely. We present the case of a 31-year-old male with a recent CD diagnosis and otherwise, no past medical history presenting with a week-long history of bilateral lower extremity swelling that started in the thighs and progressed downward, accompanied by a heavy sensation in the legs and intermittent numbness. Less than 24 hours into his hospital course, the patient experienced progressive bilateral numbness, saddle anesthesia, and urinary incontinence. Subsequently, the patient was taken for STAT MRI and emergent neurosurgery to alleviate the spinal cord compression and remove/biopsy a mass at the T6-T7 level that was later defined as a B-cell lymphoma. Our objectives are to describe the etiology of IBD complicated by lymphoma, to analyze the association between IBD and lymphoma, and to investigate the role that immunosuppressants play in the development of lymphoma from IBD, which we achieve through retrospective case analysis and associated literature review on symptom constellation. There is good evidence that malignant lymphoma of the bowel is a rare but significant complication of IBD in immunosuppressant-naive patients, apparently being more common in chronic UC. We suggest increased surveillance for this disease in immunosuppressant-naive patients, as the prognosis of lymphoma depends on the time of diagnosis.