[Primary intracranial yolk sac tumor developing in the frontal lobe from the inside of the sphenoidal ridge].

A case of primary intracranial yolk sac tumor, the first known case growing in the frontal lobe, is compared with similar cases of suprasellar region. The case, 18-year-old female, suffered from headache, vomiting and visual disturbance for one month prior to the hospitalization. Plain CT scan demonstrated suppressed left anterior horn and normal density area in front of it. After injection of contrast medium, the area was enhanced distinctly. The left carotid angiography displayed a hypervascular mass in the suprasellar region and tumor stain was also seen in the capillary phase. Bilateral frontal craniectomy was performed and the tumor was almost totally removed macroscopically. The tumor situated in the left frontal lobe infiltrated into the optic nerve and a part of anterior cerebral artery. Histologically the tumor was diagnosed as yolk sac tumor according to Teilum's classification. There were stellate cells arranged in loose vacuolated network which formed cystic cavities and a complicated network of honeycomb with communicating cavities and extracellular PAS-positive hyaline globules. Glomerular-like structures (Schiller-Duval body) was also seen. Immunoperoxidase study clearly demonstrated the presence of intracytoplasmic alphafetoprotein granules in the tumor tissue. In radioimmunoassay, the level of the serum alphafetoprotein measured was two folds higher than that of the normal range, postoperatively. Although irradiation (local 3000 rads, whole 3000 rads) combined with chemotherapy (ACNU, Futraful), PSK had almost no effect. The effect of other chemotherapy (Cis-platin, VBL, Bleomycin) was indicated by the diminish size of the tumor. Five months after the onset, she was discharged with almost no neurological findings other than left visual loss. Pathological findings and clinical treatments were also discussed in detail.