Chronic Lymphocytic Leukemia in the Colon

Abstract

Introduction: Chronic lymphocytic leukemia (CLL) is a malignancy of B lymphocytes generally affecting those over the age of 60. CLL patients have more than twice the risk of developing a second cancer due to the disease or its therapy. The most common cancers reported are prostate, lung, female breast, colorectal, bladder, and skin cancers.1,2 We report an unusual case of CLL found in the ascending colon of a patient with 5-year history of CLL stage 0. Methods: Surveillance colonoscopy was performed under direct visualization by Dr. Bikram Bal. Results: This is a 65-year-old Caucasian female with history of colon polyps and CLL stage 0 diagnosed 5 years prior. High-risk surveillance colonoscopy was performed and it found a 5-mm sessile polyp in the ascending colon, small internal hemorrhoids, and few cecum diverticula. The ascending colon polyp was removed and sent for pathology, which described prominent submucosal nodular lymphoid aggregate with overlying benign-appearing colonic mucosa. The lymphoid aggregate was composed of small round to slightly irregular lymphocytes without infiltration into surrounding mucosa. Immunohistochemistry displayed CD20, PAX5, and CD5 positivity diffusely with aberrant diffuse expression of BCL-2. Final diagnosis was mucosal CLL. Her preceding diagnosis of CLL was negative for ZAP-70 and CD38, and positive for deletion of 13q, portraying a good prognosis. Her Rai stage 0 described an overall 5-year survival of 80% and overall 10 years of 69%. She was not being treated for her CLL and there were no guidelines for treatment of colonic CLL. Her white blood count (WBC) from the previous year was 14,000. When she was referred to oncology for her colonic CLL, her WBC modestly rose to 18,900 with 14,200 absolute lymphocytes, but she remained asymptomatic. She conservatively receives annual complete blood count (CBC) surveillance and age-appropriate cancer screening only. Conclusion: Spread to the colon generally signifies transformation of CLL to diffuse large B-cell lymphoma (Richter syndrome).3 Our patient portrays a case of colonic CLL that does not indicate transformation, but there appears to be a relationship between hematologic and gastrointestinal disorders and may determine necessity of increased colon surveillance in patients with lymphoid neoplasms.Figure 1: Single polyp in cecum.