Incidental Detection of Neoplastic B Cells in the Colon Following Resection in a Patient With Adenocarcinoma.

Following a routine screening colonoscopy, a 54-year-old man underwent colon resection for adenocarcinoma, which revealed neoplastic B-cells in the lymph nodes surrounding the colon suggestive of chronic lymphocytic leukemia (CLL). Further evaluation identified a monoclonal B-cell population, and he was diagnosed with monoclonal B-cell lymphocytosis without meeting CLL diagnostic criteria. The patient had no clinical signs of leukemia and did not need acute treatment but was placed under annual surveillance. This case highlights the incidental discovery of neoplastic B-cells, emphasizing the importance of comprehensive histopathological evaluation and clinical correlation to guide management and monitoring for potential progression to CLL.