LYMPHOMATOID GRANULOMATOSIS - EVIDENCE OF IMMUNOPHENOTYPIC DIVERSITY AND RELATIONSHIP TO EPSTEIN-BARR-VIRUS INFECTION

We studied open-lung biopsies from 17 patients with pulmonary lymphoma toid granulomatosis (LYG) using paraffin-section immunostains and Epst ein-Barr virus (EBV) RNA in situ hybridization to assess the phenotype of these unique tumors and to clarify the role of EBV infection. Hist ologically, all cases demonstrated the characteristic mixed mononuclea r cell infiltrate of lymphomatoid granulomatosis with variable numbers of cytologically atypical large lymphoid cells in a background of sma ll lymphocytes. Paraffin-section immunostains in all cases showed a pr edominance of T lymphocytes. A minor population of CD20-positive large B lymphocytes was identified in 11 cases; immunoglobulin light-chain restriction was demonstrated in four of these and immunoglobulin gene rearrangements in another case. Nuclear labelling for EBV RNA was dete cted in 10 of these 11 cases and was confined to the population of lar ge B lymphocytes. Staining for CD20 was absent in the remaining six ca ses, as was nuclear labeling for EBV RNA. However, the large atypical lymphoid cells stained for T-cell-lineage-specific antibodies in three of these cases, We conclude that some cases of lymphomatoid granuloma tosis are B-cell lymphoma associated with EBV infection, whereas other s are of T-cell origin and are probably unrelated to EBV infection.