Epstein-Barr-associated leiomyomatosis and T-cell chimerism after haploidentical bone marrow transplantation for severe combined immunodeficiency disease

Background: The clinical course of Epstein-Barr virus (EBV)associated smooth muscle tumors is variable and there are no reports in patients with mixed T-cell chimerism after bone marrow transplantation (BMT). Observations: A child with X-linked severe combined immunodeficiency disease developed multiple renal and pulmonary leiomyomata 8 years after haploidentical BMT. Epstein-Barr viral DNA was detectable in the blood and in situ hybridization for EBV-encoded RNAs was positive in the tumor. The tumors have been radiographically stable, chimerism remains mixed, and plasma EBV DNA has been repeatedly negative for over 2 years after donor lymphocyte infusion. Conclusions: EBV-associated smooth muscle tumors may occur in patients who are partially reconstituted after BMT for severe combined immunodeficiency and may not require surgery or chemotherapy.