Patient went on to have surgery.

Histology

MICROSCOPIC DESCRIPTION: Sections of brain tissue show a cohesive tumor forming solid sheets with cells containing abundant amphophilic cytoplasm, vesicular nuclei and prominent nucleoli. Focally tumor cells form papillary structures and glands. Frequent mitoses and focal necrosis are present. Immunohistochemical results show tumor cells stain: CK7+, CK20-, ER- and PR-.

FINAL DIAGNOSIS:

Cerebral metastasis - poorly differentiated adenocarcinoma consistent with the known history of metastatic endometrial carcinoma. 

Discussion

Distinguishing cerebral abscesses from metastases from cystic GBM can be difficult, even on MRI. It is certainly reasonable to raise the possibility of cerebral abscess on CT particularly if there are no compelling clinical reasons to think that it should not be the case.