Final Diagnosis: Left frontal brain tumour, resection: Metastatic carcinoma.

Microscopic Description:

Sections show brain parenchymal fragments heavily involved by metastatic tumour. The tumour cells form cohesive clusters and sheets of highly malignant cells with frequent mitoses and areas of necrosis. The tumour border is relatively well circumscribed. In the adjacent gliotic brain parenchyma, capillary-sized blood vessels appear markedly thickened with hyalinized walls and sometimes a perivascular lymphocytic infiltrate. Tumor cells are strongly immunoreactive for CK7. Immunohistochemistry for CK20, GCDFP, progesterone and estrogen receptors, CDX2 and TTF-1 are negative. This immunoprofile may still represent a primary from lungs and upper gastrointestinal tract.

Interestingly, the above mentioned thick capillaries are surrounded and infiltrated by many CD4+ cells and some CD8+ reactive T-cells. Also, HLA-DR expression is increased especially in microglia and endothelial cells. These changes are consistent with the patient's history of scleroderma.