Characterization of malignant and non‐neoplastic cell phenotypes in highly malignant non‐Hodgkin lymphomas

Malignant and non‐neoplastic cells in 38 cases of highly malignant non‐Hodgkin lymphomas: 3 centrocytic anaplastic, 18 centroblastic, 13 immunoblastic and 4 lymphoblastic (according to the Kiel classification) were immunophenotyped in cryosections and cell suspensions by means of monoclonal antibodies. Additionally, cell cycle analysis on cell suspensions was performed by DNA flow cytofluorometry. In 33 (87%) lymphomas the malignant cells expressed monoclonal surface immunoglobulin (Ig), which indicated B‐cell origin of tumors. In 7 of the 19 B‐cell lymphomas tested by the peroxidase‐antiperoxidase method, cytoplasmic Ig was found. Four lymphomas were of T‐cell and one of non‐B/non‐T‐cell origin. In 11 B‐cell and 2 lymphoblastic non‐B‐cell tumors, common acute lymphobiastk leukemia antigen (CALLA) was found. In 25 of 30 studied NHL the mafignant cells expressed receptor for transferrin and in 19 of 28 cases a high percentage of cells in S‐phase (> 10.85%) was found. Number and distribution as well as type of non‐B‐cell infiltrating B‐cell‐derived lymphomas varied considerably from case to case. Among these cells Leu 3+ (T heloer/inducer) cells predominated. Leu 2+ (T suppressor/cytotoxk) and Leu 7+ (natural killer and killer) cells constituted less numerous groups. Correlation of cytodiagnostic analyses with clinical observations indicates that high content of infiltrating T cells may be a favorable prognostic feature in highly malignant B‐cell lymphomas.