rectal lymphoma: report of a rare case and review of literature.

colorectal lymphoma is an extremely rare disease, representing less than 0.5% of all primary colorectal neoplasms. the disease is usually diagnosed in the advanced stages because of its primary non-specific symptoms. the most common involved site is cecum followed by rectum and ascending colon. diffuse large b-cell lymphoma is a more frequent subtype. although surgical resection is often technically feasible, optimal therapy for a colorectal lymphoma, especially rectal lymphoma, has not yet been identified. the authors describe a patient with the primary rectal lymphoma, high-grade features and complete response to chemotherapy.