Characterization of surface markers and cytoplasmic organelle in benign and malignant lymphoid lesions of skin; immunohistochemical and electron microscopic evaluation.

In order to characterize the benign and malignant proliferation of lymphoid cells in skin, we compared surface markers and cytoplasmic organelles of cells in cutaneous lymphoid hyperplasia (CLH), lymphomatoid papulosis (LP), mycosis fungoides (MF), Sézary's syndrome (SS) and primary cutaneous malignant lymphoma (ML). The immunohistochemical study showed cells with both T - and B-cell markers in CLH,LP and early MF, whereas cells with only the T-cell marker were seen in late MF, SS and ML. T-cells in all cutaneous lesions possessed the surface marker common to T-cells of peripheral lymph nodes, and not that of central thymus cells. Cutaneous T-cells contained clustered or scattered dense core granules. Although no specific organelles indicative of benign or malignant lymphoid proliferation were found, there were several ultrastructural features that could help identifying each form of cutaneous lymphoid lesions. These included clustered or scattered dense-core granules, the variable degree of nuclear convolutions as well as dendritic arborization, and the presence or absence of 10 nm filaments.