Synchronous colonic adenoma and intestinal marginal zone B-cell lymphoma associated with Crohn’s disease: a case report and literature review

BACKGROUND: Lymphoma and dysplasia are rare complications of long-standing Crohn's disease. We report an exceptional case of a synchronous intestinal marginal zone B-cell lymphoma (MALT lymphoma) and colonic adenoma in a Crohn's disease patient. CASE PRESENTATION: A 50-year-old male patient presented with right lower quadrant for the last 9 months. He also had associated weight loss and diarrhea alternating with constipation. Ileo-colonoscopy revealed a pseudopolypoid appearance of the colonic and ileal mucosa with many discontinuous ulcerations with a 3 cm sessile polypoid mass at 17 cm from the anal verge. Histological examination of the polypoid lesion revealed an adenoma with high grade dysplasia, while the biopsies of colonic mucosa showed histologic features of Crohn's disease. Abdominal computed tomography scan (CT scan) and magnetic resonance imaging (MRI) showed circumferential wall thickening of the colon and ileum, enlarged mesenteric lymph nodes and a sessile polypoid mass of the rectosigmoid junction. The patient was scheduled for an ileocoletectomy with resection of the upper rectum and ileorectostomy. The histological examination of the resected segment showed histologic features of Crohn's disease, a recto-sigmoid polyp with high grade. dysplasia and extensive small lymphocytic infiltrate in both colonic and ileal wall which is strongly stained by CD20 and BCL2. The diagnosis of MALT lymphoma with adenoma on a background of Crohn's disease was made. The patient successfully completed 8 cycles of Rituximab+ chlorambucil chemotherapy. Nowadays the patient is asymptomatic without evidence of lymphoproliferative recurrence 10 months after surgery. CONCLUSION: We report the first case in the literature of Malt lymphoma with colonic adenoma associated with Crohn's disease, and discuss his unique macroscopic and histological features in a patient. Without immunosuppressive therapy.