Spontaneous regression of primary intracranial germinoma. A case report.

Background: Testicular seminomas are well known to regress spontaneously at a higher incidence than other tumors. To date, there have been no reports of spontaneous regression of an intracranial germinoma, although these tumors are histologically identical to testicular seminomas.

Methods: The authors present a patient with a primary intracranial germinoma that regressed spontaneously.

Results: A 21-year-old man was admitted to the study facility with acute onset of headache and vomiting. He had a 3-year history of polydipsia and polyuria. Computed tomography (CT) demonstrated a large tumor in the third ventricle, accompanied by hydrocephalus. He underwent ventriculoperitoneal shunt placement on the second day of hospitalization. A CT scan obtained on the fifth postoperative day demonstrated a remarkable decrease in tumor size. Because serial magnetic resonance imaging (MRI) demonstrated a gradual decrease in tumor size, tumor resection was not performed at that time. The patient was discharged and followed with MRI. The tumor continued to regress for more than 2 months. The patient was readmitted due to tumor regrowth, confirmed by MRI 4 months after the initial admission, despite the absence of symptom exacerbation. Two weeks later, the suprasellar portion of the tumor was resected through a right frontotemporal craniotomy. The histopathologic diagnosis was a germinoma. No concurrent tumors were found on whole body examination. The residual tumor gradually regressed after conventional radiation therapy and there has been neither tumor recurrence nor metastasis to date.

Conclusions: Although the precise cause of the transient partial regression is unknown, this case indicates that, like their testicular counterparts, intracranial germinomas may on occasion spontaneously regress.