[Malignant astrocytoma following radiotherapy in pituitary adenoma: case report]

A case of malignant astrocytoma following radiotherapy for pituitary adenoma is presented in detail with a review of the literature. A 38 year-old housewife had developed a growth-hormone secreting pituitary adenoma, and received a total of 50 Gy at the pituitary region. Four years and six months later, she began suffering headache and vomiting. Computed tomography showed an extensive low density with ring enhancement in the right temporal region, corresponding to the previously irradiated field. A right frontotemporoparietal craniotomy was carried out, and a soft and reddish tumor was partially removed. The histological diagnosis was that of malignant astrocytoma. The patient was submitted to postoperative radiochemotherapy, receiving a total of 60 Gy, nimustine hydrochloride (ACNU), and tegafur (FT). Subsequently, after three months of clinical relief, she developed tumor regrowth, and died four months later. The present case fulfills the criteria for radiation-induced tumor established by Cahan et al.: A tumor location within irradiated area, no evidence of tumor prior to radiotherapy, a long latency period between radiation and tumor occurrence, and histological verification of the tumor. Thirty-nine cases of radiation-induced gliomas including the present case have been reported in the literature. It is noteworthy that the majority occur in the younger age bracket. Male preponderance is noted as it is in primary cerebral gliomas. The primary lesions for radiation frequently include leukemia and lymphoma. Craniopharyngioma, pituitary adenoma, and medulloblastoma etc are also included.(ABSTRACT TRUNCATED AT 250 WORDS)