Background: Non-Hodgkin’s lymphoma of the colon is a rare and consequently poorly studied extranodal lymphoma. Most of the previous publications used old pathologic classifications and old diagnostic and treatment approaches.

Objective: To examine the clinical presentation, pathologic classification, treatment and outcome of patients with NHL[1] of the colon.

Methods: A retrospective study was performed of all patients with NHL and involvement of the colon in two medical centers. The patient group consisted of 17 patients over a 13 year period.

Results: Fourteen patients had primary involvement and 3 secondary. The ileocecal region and cecum were the most frequent sites of involvement, occurring in 76% of patients. Most patients had bulky disease: three had a diameter > 5 cm and eight a diameter > 10 cm. Aggressive histology was found in 12 patients: diffuse large B cell lymphoma in 11 and peripheral T cell lymphoma in 1. Three patients had mantle cell lymphoma and two had indolent lymphomas: mucosa-associated lymphoid tissue (n=1) and small lymphocytic (n=1). Eleven patients underwent hemicolectomy: right sided in 9 and left sided in 2, and 5 DLBCL[2] patients required emergency surgery for intestinal perforation. The median overall survival was 44 months (range 1–147). Disease stage influenced prognosis; six of seven patients with limited-stage DLBCL who received aggressive chemotherapy achieved complete remission and enjoyed prolonged survival, whereas patients with aggressive disseminated disease had resistant disease and poor survival (median 8 months).

Conclusions: Most colonic lymphomas are aggressive B cell lymphomas. Diagnosis is often delayed. Early diagnosis may prevent perforation. Those with limited-stage disease when treated with aggressive chemotherapy may enjoy prolonged survival. 
The role of elective hemicolectomy to prevent perforation should be examined in prospective trials.

[1] NHL = non-Hodgkin's lymphoma
[2] DLBCL = diffuse large B cell lymphoma