SUMMARY
An 82-year-old man known case of chronic lymphocytic leukemia (CLL) presented with fever and weakness. He had never received any treatment for his CLL in the past. On admission he was found to be in mild respiratory distress with bilateral crackles and had markedly elevated white blood count (WBC) (137 K/uL with 93% lymphocytes). His respiratory status deteriorated necessitating noninvasive ventilatory support. Chest computed tomography (CT) scan revealed bilateral diffuse ground glass opacities, so broad spectrum antibiotic therapy was initiated. Despite that, he remained febrile and cultures were all negative. Chest x-rays showed progressive worsening of diffuse alveolar opacities. Bronchoalveolar lavage (BAL) was negative for infectious etiologies, however flow cytometry of the fluid was consistent with CLL. Chemotherapy with chlorambucil was started. Although most of the pulmonary infiltrates in CLL patients are due to infectious causes, leukemic cells infiltration should be considered as well in CLL patients with respiratory symptoms who do not respond appropriately to standard antimicrobial regimen.