primary intracranial choriocarcinoma
Intracranial choriocarcinomas are rare, accounting for only 5% of all pineal masses and 10% of all intracranial germ cells tumors . Like other intracranial germ cell tumors, they are found both in the pineal and suprasellar region. Typically they have increased CSF and plasma b-HCG, which are helpful in establishing the diagnosis .
These tumors are highly vascular and have a propensity to hemorrhage (as do their metastases). If present blood products may be evident on MRI as signal drop-out and blooming on T2* sequences and intrinsic high T1 signal, which needs to be distinguished from calcification and fat respectively .
They have a propensity to metastasize haematogenously .