Chronic Lymphocytic Leukemia Manifesting as Colon Polyps

Abstract

Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative disorder and the most common leukemia in the U.S. representing 30% of all leukemias. CLL is a disease of the elderly; mean age of 70 at diagnosis and often asymptomatic. Lymphadenopathy, splenomegaly, and hepatomegaly are common findings. CLL cells can infiltrate any organ but gastrointestinal mucosal involvement is rare. A 54 y/o African-American male presented for screening colonoscopy. Initially diagnosed with CLL in 2014 with bulky lymphadenopathy, night sweats, and weight loss. Lymph node biopsy confirmed the diagnosis showing Trisomy 12, ZAP 70 positive, and CD 38 positive. Initial treatment consisted of Bendamustine and Rituximab. Prior to colonoscopy the patient had stable lymphadenopathy but denied B symptoms and recent labs were within normal limits including LDH and CBC. Colonoscopy was poor prep and from the proximal ascending colon to distal descending colon were multiple small polyps measuring 3-4 mm in size with an appearance similar to either hyperplastic polyps versus lymphoid follicular hyperplasia. In total there were greater than 40 polyps seen. Due to these findings random polypectomies were performed. Histologic examination showed atypical submucosal lymphoid cells. Immunohistochemical staining showed diffusely positive CD5, CD20, CD79a and BCL2 staining. CD10, BCL6, and Cyclin D1 were negative; consistent with a diagnosis of CD5+ low grade lymphoma. The patient was referred to the oncology department for evaluation. The patient was noted to have no B symptoms. He did have an elevated WBC count at 19,000 with increased lymphocytes but with normal hemoglobin and platelet count. The patient's LDH was mildly elevated and subsequently he underwent PET-CT scan which showed some mildly hypermetabolic bilateral axillary lymph nodes but otherwise normal. Recommendation was routine monitoring given lack of cytopenias, B symptoms, or evidence of transformation. Diagnosis of CLL is based on strict criteria including absolute B lymphocyte count >5,000/micoL [5 x 109/L] with mature-appearing small lymphocytes with clonality. Treatment of CLL is based on disease activity judged by B symptoms, progressive increase in lymphadenopathy, pain, or the presence of symptomatic cytopenias, hemolytic anemia, progressive disease, or repeated infections. Gastroenterologists need to keep CLL on the differential when performing endoscopy on patients who have diffuse polyposis.