Immunohistochemical Study for Ki-1 and EMA Antigens in Large Cell Lymphoma including Anaplastic Large Cell Lymphoma

ABSTRACT

To evaluate the frequency of EM A and Ki-I antigen expression in the large cell lymphoma and to define the histologic characteristics of Ki-1 positive anaplastic large cell lymphoma, 40 cases of malignant lymphoma, diffuse large cell type were immunostained by Ki-I and EMA monoclonal antibodies. Eight cases of large cell lymphomas expressed EMA, among which 4 cases were positive for Ki-I antibody as well. The positive rate for EMA was much higher in T cell lymphomas than in B cell lymphomas. Among 4 cases of Ki-I positive lymphomas, 2 cases showing membrane staining of Ki-1 with prototypic histologic feature of anaplastic large cell lymphoma were classified as Ki-1 positive anaplastic large cell lymphoma(ALCL). Ki-I positive ALCL were T-cell in one and non-T, non-B cell type in the other, respectively. The remaining 2 cases of Ki-1 positive lymphomas showing cytoplasmic staining were classified as both B-cell centroblastic/centrocytic lymphoma and T-cell pleomorphic large cell lymphoma.