Unexpected Detection of Colon Lymphoma on a Tc-99m–Labeled Red Blood Cell Abdominal Scan

Abstract

A 60-year-old man was hospitalized because of intermittent tarry stools in association with right lower quadrant (RLQ) pain for 2 months. The Tc-99m–labeled RBC abdominal scan revealed abnormal RBC stasis in the RLQ of the abdomen. Colonoscopy indicated a tumor larger than 3 cm at the proximal portion of the ascending colon. After biopsy, a histopathologic diagnosis of large B-cell lymphoma was made. This unusual case of a large B-cell lymphoma in the ascending colon was detected incidentally on a Tc-99m–labeled RBC abdominal scan.