Hairy Cell Leukemia Presenting with Duodenal Involvement Duodenum: A Case Report

CONTEXT: A rare case of adult hairy cell leukemia (HCL) with duodenal involvement is presented. CASE REPORT: The patient was a 48-year-old man, who had a history of hairy cell leukemia. Three days after completion of 2-chlorodeoxyadenosine (CDA) chemotherapy, the patient started experiencing abdominal pain. An extensive gastroenterological workup culminated in the patient getting an esophagogastroduodenoscopy (EGD) that revealed duodenal inflammation and biopsies were taken. The duodenal biopsy was positive for chronic inflammatory infiltrate, primarily consisting of atypical lymphocytes and plasma cells with tartrate-resistant acid phosphatase (TRAP) positivity, and hence a diagnosis of duodenal involvement with HCL was made. Repeat bone marrow biopsy done 2 weeks after finishing chemotherapy revealed residual disease. At the 3-month follow-up, the patient was asymptomatic with a normocellular marrow and no residual disease. Repeat abdomen computerized tomography (CT) scan at completion of therapy showed resolution of duodenal thickening and spleen size of 12 cm. Currently, patient is in clinical remission for 6 years with 4-6 monthly follow-up visits and continues to do well. CONCLUSION: This case is presented to highlight the first case report of HCL with duodenal involvement that was successfully treated with CDA.