Synchronous colonic B cell lymphoma and adenocarcinoma in an elderly patient treated with R-mini-CHOP followed by resection.

The simultaneous diagnosis of colonic lymphoma and adenocarcinoma in the same location is rare and presents challenges in its treatment considerations, especially in elderly patients. While previous cases have been described, there is little consistency in treatment regimens, and outcomes are generally poor. We describe the case of a man in his late 80s who presented with primary cecal and colonic B cell lymphoma, treated with R-mini-CHOP chemotherapy, but was found to have a residual adenocarcinoma in the cecum after treatment that was then successfully resected. The patient remains alive and well 3 years postoperation. This case highlights the need to consider lymphoma as a possible diagnosis for any colonic mass, and the need to consider rebiopsy of residual abnormal-appearing tissue postchemotherapy to confirm the diagnosis. Moreover, our report affirms that aggressive, curative-intent treatment with age-adjusted chemotherapy, and subsequent surgical resection is feasible for certain elderly patients with dual malignant diagnoses.