'Well-differentiated' lymphocytic neoplasms. Immunologic findings correlated with clinical presentation and morphologic features

The authors studied 48 cases of well-differentiated lymphocytic neoplasms using a panel of monoclonal antibodies applied to frozen sections. Forty-seven tumors expressed monotypic immunoglobulin, one or more B-lineage antigens, and Ia (HLA-DR) antigen. Proliferation centers expressed the T9 antigen and increased numbers of Ki-67-positive cells. One tumor was of T-cell origin, had a cytotoxic/suppressor cell phenotype, and showed anomalous loss of Leu-1 antigen. Immunophenotypic findings were correlated to the clinical presentation and morphologic features of each neoplasm. Sixteen tumors were associated with peripheral lymphocytosis (>4000/cu mm), 13 biopsies were obtained from extranodal sites, 16 tumors had proliferation centers, and 11 neoplasms had plasmacytoid features. The authors found no absolute and few statistically significant immunologic differences between the B-cell tumors according to their clinical presentation or morphologic features. Tumors associated with peripheral lymphocytosis more commonly expressed the Leu-1 antigen (P<0.01) and IgD (P<0.01) and less frequently were stained by BA-2 (P<0.05) and OKT9 (P<0.05). Plasmacytoid neoplasms more frequently expressed the Tac (P<0.01) and T9 antigens (P<0.05), and all expressed kappa light chain (P<0.05). Extranodal neoplasms more commonly expressed IgM (P<0.01). In contrast to the markedly different clinical presentation and morphologic appearance these tumors may have, the immunologic data suggest that B-cell small lymphocytic neoplasms are relatively homogeneous. For an individual case, immunophenotype does not predict clinical presentation or morphologic features.