Lymphoma of the colon

This review updates the status of the diagnosis of colonic lymphoma, whether primary or as part of a generalized presentation. Emphasis is on new entities such as mantle cell (MCL) and marginal zone (MZL) lymphomas. Presenting symptoms and signs are described where applicable and treatment and prognosis are covered briefly.

Mantle cell lymphoma has a much higher incidence of colonic presentation than previously reported, presents mostly in asymptomatic patients, and is detected microscopically in 50% of patients after a biopsy of a visually benign mucosa. Likewise, patients with MZL have a higher incidence of colonic involvement than previously described. There are reports suggesting a receptor-driven homing mechanism in lymphoma genesis for both of these entities. Newer pathologic techniques are also making possible the diagnosis of unusual entities such as peripheral T-cell lymphomas and Hodgkin disease in patients with a history of chronic inflammatory disease.

Gastrointestinal evaluation should be a part of the initial evaluation of patients with MCL and MZL, especially if it influences the decision to treat and the choice of treatment. Gastrointestinal evaluation should also be part of an adequate assessment of response and remission status in these patients, especially if the colon was originally involved. Patients with a history of chronic inflammatory bowel disease should have their biopsy specimens subjected to rigorous analysis including immunophenotypic and genotypic studies to rule out underlying lymphoma.