The embryonal cell carcinoma, which is the least frequently reported intracranial germ cell tumor is rarely found in its pure form and is usually highly malignant. Likewise, endodermal sinus tumors are rare and highly invasive. Teratomas can be either immature or mature and represent the expression of embryonic differentiation in germ cell tumors. These tumors are usually well circumscribed, round or lobulated, and multicystic, and compress the surrounding structures. The clinical presentation of tumors of the pineal region varies as much as the pathology.
Symptoms arise when the tumor invades or compresses adjacent structures, producing local effects.
The manifestations depend on the size of the lesion and whether it is an invasive tumor. Involvement of the cerebral aqueduct causes hydrocephalus and increased intracranial pressure. This is manifested by headaches, vomiting, lethargy and altered mental status. Involvement of the superior colliculus causes visual disturbance. Invasion of the thalamus can cause loss of sensation to half the body, weakness of half the body, and intermittent pain.