[Immunohistologic characterization of lymphoid cells infiltrating dysgerminoma of the ovary].

Dysgerminoma of the ovary is composed of cells that resemble primordial germ cells morphologically and connective tissue stroma with lymphoid cell infiltration, the degree of which has been discussed in correlation with the prognosis. In order to characterize the lymphoid cells histochemically, a sensitive immunoperoxidase technique was applied on serial tumor tissue sections. Monoclonal antibodies used in this study were anti-HLA-ABC, anti-HLA-DR, anti-HLe-1 (leukocytes), anti-Leu-1,-4(pan T cells), anti-Leu-2a (killer/suppressor T cells), anti-Leu-3a (helper/inducer T cells), anti-Leu-12,-14 (B cells), anti-Leu-M3 (monocytes/macrophages) and OKT-10 (myeloid and lymphoid precursors, thymocytes, activated T and B cells). Lymphoid cells identified morphologically on sections stained with hematoxylin-eosin were HLe-1 positive, and were therefore thought to originate in bone marrow. Most of them were also positive for Leu-1,-4, and they were composed of nearly equal numbers of Leu-2a positive cells and Leu-3a positive cells. Furthermore, the majority of the lymphoid cells were HLA-DR positive, consisting of a large number of OKT-10 positive cells and a small number of Leu-12,-14 positive cells and Leu-M3 positive cells which were mainly found in connective stroma encapsulating tumor tissue. Taken together, the lymphoid cells in the connective stroma were considered to be activated T cells. Tumor cells themselves lacked reactivity with anti-HLA-ABC or anti-HLA-DR, while lymphoid cells and connective stroma were HLA-ABC positive.