[Solitary brain metastasis from medullary carcinoma of the thyroid]

A 55-year-old woman first underwent total thyroidectomy in 1973, and the histopathology was medullary thyroid carcinoma. There was no familial history of endocrine neoplasm. She remained asymptomatic for the next 19 years. Neck and tracheal recurrence was treated with tracheal stent and radiation, in 1997. On July 1998, she presented with headache. Magnetic resonance imaging revealed a gadolinium enhanced mass in the left inferior temporal gyrus. Angiogram revealed a marked tumor stain feeding from the middle and inferior temporal artery. The tumor was successfully excised via a temporal craniotomy. Histopathological sections of the resected specimen confirmed the diagnosis, it demonstrated the medullary pattern that was composed of vascular stroma and clumps of cells. Immunocytochemistry, using carcino-embryonic antigen and calcitonin showed a strongly positive reaction, and MIB-1 was 5.4%. The patient subsequently underwent a course of whole brain radiotherapy, a total of 30 Gy/10 fr. She remains asymptomatic 14 months after treatment. Brain metastasis from medullary carcinoma of the thyroid is extremely rare and it does not usually occur distant spread. Thyroid carcinoma with brain metastasis tends to be identified in patients with older age, larger primary tumor, more frequent evidence of extrathyroidal invasion, and more aggressive histologies. The number of medullary thyroid carcinoma with brain metastasis is small and there has been little evidence from benefit of therapy. Neither is it clear wether radiation therapy is beneficial also is not clear. In this case, surgical resection and radiation therapy was effective against recurrence of other lesion.