Identification in situ of T lymphocytes in the dermal and epidermal infiltrates of mycosis fungoides.

Frozen tissue sections from the lesions of five patients with histologically proven mycosis fungoides were examined using a specific antihuman T-cell antiserum and an indirect peroxidase staining technique. The dermal and epidermal infiltrates were shown to comprise predominantly cells bearing the specific T-cell antigen, HTLA. Two of the patients exhibited characteristic Pautrier microabscesses whose cells were exclusively T lymphocytes.