The patient went on to have a transphenoidal resection.
MICROSCOPIC DESCRIPTION:
The sections show a moderately cellular pituitary adenoma comprising trabeculae and nests, surrounded by vascularised stroma. The tumour cells have mildly enlarged round nuclei, finely granular chromatin and moderate amounts of eosinophilic cytoplasm. There are no atypical features. No normal anterior pituitary gland tissue is present. About 50% of the tumour cells are FSH positive with moderate intensity. The Ki-67 index is about 1%. The other pituitary hormone immunostains are negative.
DIAGNOSIS:
Silent gonadotroph adenoma.