Effusion fluid cytology of lymphomas - the Hong Kong experience

Abstract

Among the 259 effusion fluia cytological specimens received from 62 cases of histologically proven lymphoma, 168 (62.5%) were diagnostic of lymphoma Infiltration. The relative incidence of different histological types and their occurence In different sites were analysed. We attempted to classify these cases cytologlcally by analysing cellularlty, nuclear features, chromatin pattern and presence of nucleoli. Correlation with the histological classification using the International Working Formulation (WF) was performed. None of the diagnostic specimens were Hodgkin's disease and only three cases were follicular lymphomas. Most of the specimens (40.7%) were from cases of diffuse, predominantly large cell. The other types Include lymphoblastic (27.2%), diffuse mixed small cleaved and large cell (9.2%), diffuse predominantly small cleaved cell (8%), immunoblastlc (3.1%), small lymphocytic (0.6%), and unclassified (8%). Lymphoblastic lymphomas more commonly involved the pleura. Cytologlcal classification predicted the histological subtype correctly In 82.7% of the diffuse lymphomas. We conclude that effusion fluid cytology is most helpful In recognising body cavity involvement by high grade lymphomas. Correlation between cytologlcal and histological classification was high, partly because most of the cases were diffuse non-Hodgkln's lymphomas.