EXFOLIATIVE RESPIRATORY CYTOLOGY IN THE DIAGNOSIS OF LEUKEMIAS AND LYMPHOMAS IN THE LUNG

Leukemias and lymphomas involving the lung were diagnosed by means of exfoliative cytology in 31 specimens from 20 patients Initial diagnost ic categorizations included 29 specimens ''positive for malignancy,'' including two thought to represent ''carcinoma vs. lymphoma, '' and tw o considered suspicious for lymphoma. Previous diagnoses of lymphoma ( 13 patients) and acute myelogenous leukemia (AML) (2 patients) were av ailable. In 5 additional patients, exfoliative respiratory cytology yi elded the first diagnosis of hematopoietic malignancy. Cytologic diagn osis included nine large-cell and six small-cell non-Hodgkin's lymphom as (NHL), three Hodgkin's lymphomas (HD), and two AML. Key cytologic f eatures included markedly pleomorphic and monomorphic cell populations in HD and NHL, respectively, as well as lack of tumor cell cohesion a nd necrosis in all cases Cytologically, acute leukemia may be difficul t to differentiate from large-cell NHL, and small-cell NHL from reacti ve/benign small lymphocytes. Blood, scant cellularity crush artifacts, and apparent molding may affect diagnostic accuracy. Immunocytochemis try in cell block sections of sputa and washings is useful in the diag nostic workup in selected cases. Although involvement of the respirato ry system by leukemias and lymphomas is uncommon and not always preced ed by a history of malignancy, cytologic diagnosis is usually prompt, reliable, and accurate. (C) 1996 Wiley-Liss, Inc.