[Morphological and immunohistochemical analysis of Ki-1 lymphoma]

We investigated 9 cases of Ki-1 lymphomas morphologically and immunohistochemically. The lymphoma cells infiltrated in the lymph nodes in 7 cases, in the skin in 6 cases, in both in 4 cases and in the bone marrow in 2 cases. In lymph nodes, the giant tumor cells infiltrated paracortical areas, showing a sheet-like appearance or free cell growth pattern and in the marginal and medullary sinuses as well. In the skin, they formed subcutaneous tumor and infiltrated diffusely also in dermis. All cases were positive for Ber-H2, Ki-1 and HLA-DR and 8 cases revealed some of the T cell phenotypes. But Leu-4 and beta F1 for which all 11 peripheral T cell lymphomas were positive, were only positive in 2 cases, respectively. In the present study, the tumor cells were positive for a few antibodies for T lymphocytes and there were few cases showed positivity for Leu-4 and beta F1. The results suggest that it was questionable whether the tumor cells were derived from T lymphocytes. There may be few cases of Ki-1 lymphomas of distinct T cell lineage.