The short-term effect of low-dose radiation on intracranial germinoma. A pathologic study.

A correlative pathologic and imaging (computed tomography and magnetic resonance imaging) study is reported of a pineal germinoma in a 35-year-old man who died unexpectedly of massive pulmonary embolism on the 8th day during the course of radiation therapy after receiving a total dose of only 1600 cGy. A histologic study of the entire lesion in serial sections revealed no viable tumor cells. The tumor bed was composed of stromal elements with a variable degree of proliferation. The lymphocytic component of the tumor was unaffected by the radiation. This case provided a rare opportunity to show total eradication of tumor cells in a germinoma after a small dose of radiation and supports the notion, based on imaging observations, that histologically proven intracranial pure germinomas may be treated successfully with a much smaller dose of radiation than previously thought.