[Incidence and characterization of large-cell anaplastic lymphoma].

PURPOSE: Large cell anaplastic lymphoma (LCAL) is a new entity among large cell lymphoma. Diagnosis is based upon morphology and on positivity to Ki1 antigen. The objectives of this study were: 1) to determine the incidence of LCAL in the patient population seen at the Instituto Roffo between 1981 and 1993; 2) to study the immunological phenotype; 3) to study the association with Epstein-Barr virus and HIV; 4) To study the expression of oncogen bcl-2 and 5) to evaluate tumoral growth factor. MATERIAL AND METHODS: The study was done on 1030 biopsies of nodal and extranodal lymphoproliferative diseases, with Hodgkin and non-Hodgkin lymphoma. Of the 1030 consecutive cases, 67 were selected. They revealed pleomorphic cells with sinusoidal disposition. Biotin and avidin peroxidase techniques were used to identify the following antigens: CD30(Ki 1), CD45RO (UCHL1), CD20(L26), CD45(CL), Epstein Barr virus (VEB), human immunodeficiency virus (HIV), CD15, CD68, PCNA, bcl-2 oncogen, vimentin, membrane epithelial antigen (EMA). Of these cases, only 10 revealed strong positive reaction to CD 30 (Ki1), thus they were considered to fulfill criteria to be classified as LCAL. RESULTS: 1. Incidence of LCAL in the lymphoma population under study was 1%. 2. Phenotype was B in 3 cases, T in 3, and macrophage in 1.3. There was 1 case of positive EBV and 3 positive HIV. 4. Eight of 10 LCAL cases were positive for bcl-2 protein. 5. Tumoral growth factor was 57%. Also, it was noted that most cases were secondary to Hodgkin lymphoma, and a few secondary to polymorphic immunoblastic lymphoma, with negative reaction to CD15 and EMA and positive for Vimentin. CONCLUSIONS: 1. Incidence of LCAL amongst patients with lymphoma is very low. 2. Immunological phenotype is varied. 3. There was no significant association with EBV or HIV. 4. Oncogen bcl-2 was demonstrated in most cases. 5. There was a high percentage of cells in proliferation.