Epstein-Barr virus-associated leiomyosarcoma of the thyroid in a child with congenital immunodeficiency: a case report.

We report an unusual case of multifocal leiomyosarcoma involving the thyroid gland, liver, and right lung in a child with congenital immunodeficiency disease. The smooth muscle nature of these neoplasms was confirmed by immunohistochemistry and electron microscopic studies. In situ hybridization showed large amounts of Epstein-Barr virus messenger RNA within the tumor cells. Although Epstein-Barr virus-associated smooth muscle tumors have been reported in children with AIDS and after organ transplantation, we are unaware of any case report in congenital immunodeficiency disease.