Non-Hodgkin lymphomas present a wider systemic diffusion than Hodgkin lymphomas. Superficial and internal nodes, the tracheobronchial tree, and the digestive tract are almost always affected. The gastrointestinal tract is affected in 50% of the cases; the stomach is the first organ, followed by the small intestine and large intestine. The colon is affected in only approximately 0.4% of cases. The clinical picture of our patient showed abdominal pain, palpable mass, and anemia. Colonoscopy showed a tumor in the cecum (diameter, approximately 10 cm) and the biopsy indicated lymphoma. Through computed tomography, bone marrow biopsy, and measurement of beta2-microglobulin, complete staging was obtained. Right hemicolectomy was immediately performed because the large tumor could determine intestinal occlusion. Definitive diagnosis was non-Hodgkin lymphoma, type mucosa-associated lymphatic tissue B cells with a low grade of malignancy. After surgery the patient underwent six courses of chemotherapy according to the CHOP scheme (750 mg/m2 cyclophosphamide, 1.4 mg/m2 vincristine, 50 mg/m2 adriamicin, and 80 mg prednisone). Two years after surgery the patient shows no sign of the disease.