Indagini istologiche, immunocitochimiche ed ultrastrutturali su quattro casi di tumore a cellule della granulosa-teca della cavalla

SUMMARY - The histological, immunocytochemical and ultrastructural characteristics of Leydig-like cells were investigated in four equine gjanulosa-theca cells tumore (GTCT). Proliferation of thè granulosa-theca cells in a follicular pattern was thè prominent microscopie finding in each tumor. Neoplastic cells were also arranged in cords, trabecular pattems or in solid insular masses. The amount of stremai or thecal reactions varied both in thè different cases and within thè same tumor. Leydig-like cells were present arnong theca cells in 3 cases. Immunocytochemical staining for testosterone was strongly positive in these cells. Ultrastructurally they were similar to thè interstitial cells of thè testìs. The rcsults of thè present study show that thè number of Leydig-like cells is related to plasma testosterone concentration and that they appear to be a source of thè testosterone production.