What are the 2 most common types of neoplasms in the pineal region?
Germ cell tumours and pineal parenchymal tumours. Other neoplasms are primarily of glial orgin or arise outside the pineal gland (e.g. meningioma).
What is the most useful lab test to determine whether a lesion is a malignant germinoma?
ß-HCG (serum or csf).
Should a biopsy be taken?
Yes, biopsy should be performed whenever possible, for it improves the therapeutic outcome in pineal region tumours, partly because of the higher radiation sensitivity of germinoma compared with other pineal tumours.
MRI shows a hypervascular, invasive lesion with perifocal oedema and infiltration of the thalamus and superior tectal plate.