The patient went on to have a transsphenoidal resection.
MICROSCOPIC DESCRIPTION: The sections show features of metastatic poorly differentiated carcinoma. The tumour forms trabeculae and nests. No glandular structures are noted. The tumour cells have enlarged pleomorphic nuclei, prominent nucleoli and small amounts of cytoplasm. No evidence of lymphovascular invasion is seen. There is no normal anterior pituitary tissue included.
- Oestrogen receptor: Negative
- Progesterone receptor: Negative
- HER-2: Positive (3+)
- Previous positive SISH noted
Pituitary metastasis: poorly differentiated adenocarcinoma, consistent with breast primary.
At best, the only good clue that this lesion may be a metastasis rather than a far more common macroadenoma is the lack of pituitary fossa enlargement and slight 'fuzziness' to the masses outline.