Three patients presented with symptoms of severe dyspnea, radiologic evidence of bilateral pulmonary infiltrates, and one had diffuse wheezing on auscultation. Open-lung biopsies revealed a neoplastic lymphocytic infiltrate in an exquisitely bronchiolocentric distribution with relative sparing of the rest of the lung parenchyma. Two patients had a history of chronic lymphocytic leukemia (CLL), whereas pulmonary disease was the initial manifestation of the lymphoproliferative disorder in the third. Clinical and pathologic features of the three cases are discussed.