Does a Normal Endoscopic Appearance of Duodenum Rule Out Underlying Hairy Cell Leukemic Infiltrate?

Abstract

Purpose: Hairy Cell Leukemia (HCL) is a form of chronic lymphoproliferative disorder. Leukemic involvement of the gastrointestinal (GI) tract must be considered in any patient with acute or chronic leukemia who presents with unusual GI symptoms. We report a patient with HCL presenting with fever, abdominal pain and was found to have hairy cell (HC) infiltration on random biopsies of endoscopically normal appearing duodenum. Methods: Our patient is a 48 year old Hispanic male with history of HCL who presented with fever for two days after one cycle of cladribine (2-CdA). Patient had temperature of 101.4 and right abdominal tenderness with no rebound, guarding or rigidity. Labs showed WBC 0.4, ANC 0.2, Hb 8.9, platelet 23, ALP 137, ALT 42, AST 32. He was started on Imipenem, Vancomycin, Diflucan and Neupogen. Extensive septic work-up was negative. HIDA scan was negative. Bone marrow biopsy done for persistent spiking of high grade fever was negative for any pathogens. Abdominal CT showed circumferential thickening of 2nd and 3rd portion of duodenum. EGD revealed a completely normal esophagus and duodenum. Random biopsies of the duodenum revealed chronic inflammatory infiltrate chiefly composed of atypical lymphocytes and plasma cells. Immunohistochemical stains of paraffin sections of biopsy revealed atypical lymphocytes positive for TRAP (tartrate resistant acid phophatase), consistent with hairy cell leukemic infiltrate of duodenum. Patient's WBC subsequently improved on Neupogen and he was discharged. Results: Conclusion: Extramedullary involvement of the GI tract with leukemia is very rare and usually involvement of lymphoreticular organs, brain, testes and ovaries is seen. The reported autopsy incidence of GI involvement by leukemia ranges from 5.7% to 13% and reaches upto 20% in cases of acute lymphocytic leukemia. Leukemic involvement of the GI tract can be from mouth to anus with duodenum and distal colon being least commonly affected. Macroscopically, GI tract involvement can assume a variety of forms, including necrosis, hemorrhage, ulceration, inflammation or polypoid lesions. We did not find any case in literature with duodenal infiltration by hairy cell leukemia having a normal endoscopic appearance. Acute presentations may include necrotizing enteritis, perforation and abscesses. Radiographic studies may show thickening of bowel wall or ulcerations. Differential should include any underlying infectious etiology. Recurrent GI symptoms in a patient with known leukemic involvement of the GI tract should raise suspicion for leukemic relapse or progression. If index of suspicion is high, random biopsies should be taken regardless of the gross mucosal appearance, as a normal appearing mucosa does not rule out underlying pathology.