Feasibility of the immunohistochemical detection of endogenous steroids in paraffin-embedded ovarian tumours

Abstract

Formalin-fixed, paraffin-embedded samples from 25 ovarian granulosa cell tumours and six poorly differentiated ovarian carcinomas were examined immunohistochemically for the presence of estradiol, testosterone and progesterone. Twenty-four of the 25 granulosa cell tumours stained for estradiol predominantly in granulosa cells and also in the theca cells, but none of the carcinomas were positive. All the granulosa cell tumours and five out of six carcinomas were positive for progesterone, while 13 granulosa cell tumours and three carcinomas stained moderately positive for testosterone. No clear-cut relationship was observed between positivity for estradiol in granulosa cell tumours and occurrence of endometrial hyperplasia. In two cases of granulosa cell tumours, 1-15% cells showed ultrastructural features of steroid synthesis: i.e. moderate to abundant smooth endoplasmic reticulum and mitochondria with tubular cristae. This is in contrast with the diffuse immunohistochemical staining reaction of granulosa cell tumours with antisteroid antibodies. To evaluate the significance of immunohistochemical reactions for estradiol, four estradiol-containing tumours were tested by radioimmunoassay for the presence of estradiol before and after dehydration. As expected, treatment with organic solvents leads to a drastic reduction in estradiol content below the detection level of the assay. The results indicate that immunohistochemical staining for steroids of paraffin-embedded granulosa cell tumours is of limited value.