Cutaneous malignant melanoma: a fresh outlook

Characterization of the inflammatory infiltrate in ovarian dysgerminoma: an immunocytochemical study

The inflammatory infiltrate has been characterized in 10 cases of ovarian dysgerminoma using a panel of antisera to T-cells, B-cells and macrophages. The expression of Class II major histocompatibility complex (MHC) antigens and the distribution of interferons alpha and gamma were also examined. T-lymphocytes were present in all tumours, often closely admixed with neoplastic elements. T-cells in most areas were immunoreactive with gamma interferon. B-cells were generally scanty although germinal centres were present in three tumours. Immunocytochemistry revealed greater numbers of macrophages than had been appreciated on routinely stained sections. Macrophages were closely related to both lymphoid and tumour cells, and many macrophages were immunoreactive for alpha interferon. Class II MHC expression was mainly restricted to macrophages and B-cell areas although occasional T-cells were also stained. Dysgerminoma cells did not express Class II MHC antigens.

Is poor prognosis really related to HLA-DR expression by malignant melanoma cells?

HLA-DR expression was examined in 50 consecutive primary cutaneous malignant melanomas with a Breslow depth greater than 2 mm using two well-characterized monoclonal antibodies which detect fixation-resistant epitopes. In 31 of these cases (62%) a subpopulation of tumour cells was reactive, although there was considerable heterogeneity. Positive labelling did not correlate with depth but was associated with a reduced likelihood of developing early metastatic disease and a tendency for better overall survival, particularly in male patients. These findings contrast with earlier studies using cryostat sections and one study on paraffin-embedded tissue in which HLA-DR expression was shown to be a poor prognostic factor, but are consistent with the findings in other malignant tumours studied. The significance of HLA-DR expression as a marker of prognosis may depend on the type of tissue preparation, the sensitivity of the immunocytochemical techniques used and the method of assessment.