Primary lymphoma of the colon and rectum is rare, and it occurs mainly in the rectum and the caecal region. Secondary lymphoma is more usual in the colon than in the rectum. Generalized lymphoma often causes gross intra-abdominal lymphadenopathy.

These pictures show changes in the rectum due to large pelvic lymph nodes in a patient with generalized lymphoma. In rectum, the mucosa was intact. In the distal sigmoideum, break through of the lymphatic tissue was seen.

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