Utility of flow cytometry immunophenotyping for the diagnosis and classification of lymphoma in community hospital clinical needle aspiration/biopsies.

Abstract

Flow cytometry immunophenotyping (FC) of needle aspiration/biopsy (NAB) samples has been reported to be useful for the diagnosis and classification of lymphoma in university and cancer center-based settings. Nevertheless, there is no agreement on the utility of these methods. To further define the utility of adjunctive FC of clinical NAB for the diagnosis and classification of lymphoma, and to determine if this approach is practicable in a routine clinical practice setting. A community-based hospital. Clinical NABs were submitted for adjunctive FC between June 1996 and September 1999 if initial smears were suspicious for lymphoma. Smears and cell block or needle core tissues were routinely processed and paraffin-section immunostains were performed if indicated. The final diagnosis was determined by correlating clinical and pathologic data, and the revised European-American classification criteria were used to subtype lymphomas. Needle aspiration/biopsies from 60 different patients were submitted for FC. Final diagnoses were lymphoma (n = 38), other neoplasm (n = 15), benign (n = 6), or insufficient (n = 1). For 38 lymphomas (20 primary, 18 recurrent), patients ranged in age from 32 to 86 years (mean, 62 years); samples were obtained from the retroperitoneum (n = 11), lymph node (n = 9), abdomen (n = 8), mediastinum (n = 6), or other site (n = 4); and lymphoma subtypes were indolent B-cell (n = 20; 2 small lymphocytic, 14 follicle center, 4 not subtyped), aggressive B-cell (n = 14; 3 mantle cell, 10 large cell, 1 not subtyped), B-cell not further specified (n = 2), or Hodgkin disease (n = 2). For the diagnosis of these lymphomas, FC was necessary in 20 cases, useful in 14 cases, not useful in 2 cases, and misleading in 2 cases. Thirty-two of 36 lymphoma patients with follow-up data received antitumor therapy based on the results of NAB plus FC. Adjunctive FC of NABs is potentially practicable in a community hospital, is necessary or useful for the diagnosis and subtyping of most B-cell lymphomas, and can help direct lymphoma therapy. Repeated NAB or surgical biopsy is necessary for diagnosis or treatment in some cases.