[Smooth muscle mesentery associated with Epstein-Barr virus (EBV). Report of a case in a child with a liver transplant under FK506 regimen]. / Tumeur musculaire lisse mésentérique associée au virus d'Epstein-Barr (EBV). A propos d'un cas chez un enfant transplanté hépatique sous FK 506.

ABSTRACT

Smooth-muscle tumors, benign and malignant, are increasingly recognized in children who are immunocompromised because of HIV infection and organ transplantation. We report a case of an EBV-associated smooth-muscle tumor, of unusual location arising in a seven-year-old post-transplant patient who was previously treated for a lymphoproliferative disease. Five years after liver transplantation, a mesenteric tumor was diagnosed. The tumor was composed of spindle cells with smooth-muscle features. Immunohistochemical analysis was positive for muscle-specific actin and desmin, negative for EBV latent membrane protein (LMP-1). In situ hybridization revealed nuclear EBV sequences. This case underlines the role of EBV infection in the development of unusual smooth-muscle tumors after organ transplantation. The evolution of these rare tumors is uncertain.