Radiology Resident Case of the Week
Clinical Sx:
4 year old male with headache and mental status changes.
Pathology:
Embryonal cell carcinomas are composed of large, malignant, totipotential, undifferentiated embryonal-type epithelial cells. Both tumor markers, alpha-fetoprotein and human chorionic gonadotropin, are elevated with embryonal cell carcinomas.
Imaging:
Imaging findings are nonspecific. Malignant tumors of the pineal gland have prolonged T1 and T2 relaxation times, and their infiltrative growth incites a perifocal edema.
Computer Tomography:
Unenhanced 
Enhanced
Magnetic Resonance Imaging
DDx:
Pineal region masses account for 1% to 2% of all brain tumors in adults, but constitute 3% to 8% of intracranial tumors in children. Common pineal gland tumors are neoplastic derivatives of multipotential embryonic germ cells. These tumors account for more than two thirds of all pineal region masses and include in order of decreasing frequency germinoma, teratoma, choriocarcinoma, endodermal sinus (yolk sac) tumor and embryonal carinoma. Tumors that arise from pineal parenchymal cells account for less than 15% of all pineal region neoplasms and include pineocytoma (benign) and pineoblastoma (malignant). Nonneoplastic pineal cysts are benign cystic lesions of unkown etiology and should also be included in the differential of cystic pineal gland lesions. Sarcoidosis has also been reported as causing a focal pineal mass.
DDx includes menigiomas of the quadrigeminal region as well.
Key references:
T-1 (coronal)
T-1 (sagital)
T-2 (axial)
PD (axial)