Fine needle aspiration diagnosis of malignant lymphoma with confirmation by immunoperoxidase staining.

Cytospin preparations of fine needle aspirates in 14 cases of suspected lymphoma were studied by immunoperoxidase techniques. The combination of cytologic smears and immunoperoxidase studies resulted in a working diagnosis in 13 of the 14 cases. The immunologic markers in conjunction with the cytologic appearance of the aspirates were reliable and consistent in differentiating between malignant and benign lymphoproliferative lesions and in determining the B-cell or T-cell nature of the process.