One patient, two lymphomas, three primaries.

Concomitant adenocarcinoma and non-Hodgkin's lymphoma, both located in the intestinal tract, are unusual. Collision tumors of the colon on the other hand are extremely rare neoplasms. A case of true collision tumor of a marginal zone lymphoma and a moderately differentiated adenocarcinoma of the ascending colon (hepatic flexure) is reported. Simultaneously, a third primary is identified as follicular lymphoma involving the terminal ileum. Correlation with clinical history, radiology investigations, endoscopic findings and histological examination of the resected specimen as well as the use of ancillary techniques such as immunohistochemistry are the most useful in making the correct diagnosis of a synchronous three primaries involving the small bowel and colon. Therefore, we present these three primary synchronous neoplasms involving two different parts of the gastrointestinal tract, with two of these three primaries colliding at one organ.