Demonstration of histiocytes in the epidermal infiltrate of mycosis fungoides

Ichthyosiform mycosis fungoides: report of a case associated with IgA nephropathy

We report a case of ichthyosiform mycosis fungoides (MF) associated with IgA nephropathy. Histological examination showed a dense atypical lymphocytic infiltrate admixed with epithelioid cells and giant cells in the dermis associated with the features of epidermotropism and folliculotropism. Reported cases of ichthyosiform MF are reviewed and histopathological characters of ichthyosiform MF are summarized. We suggest a histiocyte/dendritic-cell-rich infiltrate, or granulomatous features of infiltrate may be another characteristic of ichthyosiform MF. This case was associated with IgA nephropathy, which is uncommon. Such a presentation has never been reported in the literature.

Pagetoid reticulosis, epidermotropic mycosis fungoides and mycosis fungoides: a disease spectrum

Using a standard technique involving monoclonal antibodies against T-cell subsets, we have shown that almost all the infiltrating T-cells in the epidermis of a patient with Pagetoid reticulosis (PR), one with epidermotropic mycosis fungoides (EMF) and one with poikiloderma atrophicans vasculare (PAV), were OKT8 positive (presumed cytotoxic/suppressor) T-cells. The infiltrating T-cells in the epidermis of a patient with limited plaque stage mycosis fungoides (MF), however, were almost exclusively Leu 3a-positive (presumed helper/inducer) T-cells as is usually found in this condition. The keratinocytes in the patients with PR, EMF and PAV were HLA-DR-positive whilst those in the patient with MF were HLA-DR-negative. We consider these four diseases to be part of the spectrum of mycosis fungoides, the first three conditions representing the early or benign end of the spectrum.

Langerhans cells in verruciform xanthomas: an immunoperoxidase study of 10 oral cases

Ten oral verruciform xanthomas were studied using an immunoperoxidase stain for S-100 protein. All cases exhibited positively stained dendritic cells among the mononuclear inflammatory cell infiltrate at the base of the lesions and to a lesser extent among the "foam cells". The foam cells were, however, negative for S-100 staining. We suggest that, based on these findings, verruciform xanthomas belong to a new category of "non-X histiocytoses" in which the presence of Langerhans cells suggests an immunologic pathogenesis.

Significance of non-lymphoid ('accessory') cells in malignant lymphomas and pseudolymphomas of the skin

We investigated the co-distribution of lymphocyte subpopulations and non-lymphoid 'accessory' cells in 35 cases of cutaneous lymphoproliferative diseases (T-cell lymphoma, 10 cases; B-cell lymphoma, 17 cases; pseudolymphoma, 8 cases) using immunohistochemical methods. T-zone histiocytes and particularly Langerhans cells were abundant in all cutaneous T-cell lymphomas, but were also found in B-cell lymphomas. T-zone histiocytes were associated with T-lymphocytes, especially T-helper cells, but not with T-suppressor cells. Dendritic reticulum cells were essentially confined to well differentiated germinal centres. Macrophages occurred in both lymphomas and pseudolymphomas without definite relationship with either B- or T-cells. In malignant lymphomas of high grade malignancy, macrophages represented the only non-lymphoid cell type. Our results indicate that malignant lymphoid cells, like normal lymphocytes, require definite micro-environments which are, at least in part, maintained by certain non-lymphoid cells.

The intracutaneous growth of murine lymphomas: epidermal invasion is characteristic of multiple tumor phenotypes

Affinity of lymphoid cells for the epidermis (epidermotropism) is characteristic of the cutaneous T-cell lymphomas, mycosis fungoides and the Sézary syndrome. Consistent with numerous studies indicating that mycosis fungoides is a neoplasm of OKT4+T8- ("helper/inducer") T lymphocytes is the possibility that epidermotropism is a phenotypic hallmark of this subset of malignant T cells. This proposal was investigated in mice using 8 phenotypically characterized lymphomas of BALB/c origin: 3 histiocytic (phagocytic, lysozyme-positive, FcR+, Ig-, Thy 1-), 1 B-cell (IgM+, FcR+, Thy 1-), and 4 T-cell (Ig-, Thy 1+) lines, including 1 with markers of mouse helper/inducer T cells (Lyt1+23-), 2 with suppressor/cytotoxic markers (Lyt1-23+), and 1 with markers of immature thymocytes (Lyt1+23+). The intracutaneous growth pattern of these lines was studied on hematoxylin and eosin-stained sections through the centers of tumors obtained at times after intradermal injection into parallel groups of syngeneic mice. All of these lymphomas manifested variable epidermotropism that followed a typical sequence. Following dermal growth and spread to the dermal-epidermal junction, tumor cells appeared within the stratum spinosum. Subsequently, collections of cells appeared in spaces within the epidermis (Pautrier-like microabscesses) in tumors greater than 2 cm in diameter, coincident with early epidermal necrosis. Thus, in this animal model it is clear that the intraepidermal invasion/growth does not correlate with the helper/inducer T-cell surface phenotype. These observations are nonetheless consistent with recent studies using monoclonal antibodies to cell surface antigens which have demonstrated a heterogeneity of lymphoid cell subsets within the epidermis in lesions of mycosis fungoides and of other malignant and benign dermatoses.

A technique for immunoultrastructural identification of T6-positive Langerhans cells and indeterminate cells in mycosis fungoides

An immunoelectron microscopic method was developed using T6 antiserum in an immunoperoxidase technique to label the dendritic cells of the epidermis in mycosis fungoides (MF). The technique allows simultaneous identification of intracellular Birbeck granules and T6 membrane positivity. Ultrastructural examination of the epidermal infiltrate of MF, using this method, confirmed the T6-positive nature of Langerhans cells and indeterminate cells. All Sézariform and mature lymphocytes were T6-negative and a small population of T6-negative histiocytic cells were also observed.