A Germinoma involving the hypothalamic region. The other major site of tumors is the pineal region.

These two images illustrate the microscopic appearance of the Germinoma. The tumor is composed of primitive germ cells distributed in a lobular array separated by a lymphocytic-rich stroma.

Germinoma: These tumors arise from germ cells and are most common in the region of the pineal gland. They are thought to arise from cells that should have migrated to the gonads during development. They are highly infiltrative and rapidly growing.