Fine needle aspiration cytodiagnosis of Hodgkin's disease and its subtypes. II. Subtyping by differential cell counts.

Differential cell counts were performed on fine needle aspiration (FNA) smears from 96 cytologically diagnosed and subsequently biopsy-proven cases of Hodgkin's disease (HD). Reed-Sternberg cells and Hodgkin cells showed a definitely increasing trend in three major HD subtypes (as diagnosed on the smears): lymphocytic predominance (LP), mixed cellularity (MC) and lymphocytic depletion (LD). Lymphocytes, on the other hand, showed a decreasing trend between these subtypes. The differences in the percentages of Hodgkin cells, Reed-Sternberg cells and lymphocytes were highly significant (P less than .001). No trends (increasing or decreasing) were observed in the smear content of other reactive components (non-neoplastic histiocytes, eosinophils, plasma cells and neutrophils). In 88.0% to 95.0% of the cytologically diagnosed cases of LP, MC and LD subtypes, the percentages of Hodgkin cells plus Reed-Sternberg cells fell within a distinct range: less than 1.5% for LP, greater than or equal to 1.5% to less than 7.5% for MC and greater than or equal to 7.5% for LD. Analysis of the data based on histopathologic subtyping of the cases showed similar significant trends in the proportions of Hodgkin cells, Reed-Sternberg cells and lymphocytes, with 70.0% to 80.0% of the LP, MC and LD subtype cases within these ranges. These results demonstrate the validity of the subjective subtyping of HD on FNA smears in most cases.