Lymphoma of the colon: the spectrum of radiologic changes.

Primary lymphoma of the colon is rare and comprises less than 1% of large bowel malignancies. Secondary colonic involvement in patients with advanced lymphoma is not uncommon and is frequently undetected. The radiographic findings of 34 patients with colonic lymphoma were reviewed. Thirteen patients had primary tumors, while the remaining 21 had colonic involvement secondary to systemic disease. The radiologic features were classified as mucosal nodularity, endo-exoenteric mass, intraluminal mass, mural infiltration, and mesenteric invasion. One patient with diffuse mucosal nodularity developed acute colonic dilatation, while two other patients had pneumatosis coli secondary to local tumor depositions. Lymphoma is now a well-described complication of chronic ulcerative colitis, and a further case is described here. Although colonic lymphoma is a relatively rare tumor, the spectrum of radiologic changes reviewed here may enable a more accurate radiologic diagnosis.