Pulmonary Involvement in Chronic Lymphocytic Leukemia: A Structured Diagnostic Approach to Diffuse Infiltrates-A Case Report.

Pulmonary abnormalities in chronic lymphocytic leukemia (CLL) usually reflect infection, pleural effusion, treatment toxicity, second malignancy, or Richter transformation. Leukemic pulmonary infiltration is underrecognized and radiologically heterogeneous. A 64-year-old man with CLL developed dyspnea, cough, and bilateral basal crazy-paving opacities on high-resolution computed tomography. Bronchoalveolar lavage showed lymphocytosis and a CD5-positive monoclonal B-cell population. Transbronchial lung cryobiopsy supported CLL infiltration and argued against mantle-cell lymphoma or transformation. Obinutuzumab plus venetoclax was followed by clinical improvement and regression of the interstitial lung opacities on follow-up imaging. This case supports combining BAL flow cytometry with tissue confirmation in this unusual pulmonary presentation. Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.