Biological characterization of ovarian granulosa cell tumours of slaughtered cattle: assessment of cell proliferation and oestrogen receptors.

Of 1489 slaughtered cattle, 11 had ovarian granulosa cell tumours (GCTs). These GCTs were examined immunohistochemically for proliferating cell nuclear antigen (PCNA) and oestrogen receptor (ER) in relation to histopathological features (growth pattern, nuclear atypia and mitotic count). On the basis of nuclear atypia and mitotic count, the prognosis for GCTs with a diffuse growth pattern appeared less favourable than that for GCTs with a follicular or trabecular pattern. Increased PCNA expression was significantly associated with nuclear atypia but not with histological growth pattern or mitotic count. A novel finding was the presence of ERbeta but not ERalpha in bovine ovarian GCTs. However, ERbeta expression did not appear to be related to the histopathological features examined. The results indicate that PCNA expression may be of value in establishing the biological behaviour of bovine GCTs. However, a larger series of bovine GCTs should be examinated to assess the prognostic significance of ERbeta.