Primary neurilemmoma of the thyroid gland in a 12-year-old girl.

A case of a neurilemmoma of the thyroid gland in a 12-year-old girl is reported. The tumor was noted as a asymptomatic left lower neck swelling 9 months before admission. Ultrasound scan showed the solid lesion of predominantly hypoechoic structure measuring 17.2 x 12 x 26 mm within the left lobe. Pathologic examination of the excised lobe was consistent with neurilemmoma with both Antoni A and Antoni B histologic patterns. To date only 14 cases of this nonepithelial tumor of the thyroid gland have been described in the literature, and all occurred in adult patients. This is the first report of thyroid neurilemmoma in a child.