Skull Base Ebstein–Barr’s Virus–Associated Smooth Muscle Tumor in an 8-Year-Old Girl with CD4+ and CD8+ Lymphopenia

Abstract

Epstein–Barr’s virus–associated smooth muscle tumor (EBV-SMT) is an extremely rare neoplasm which occurs in immunocompromised patients, such as those with AIDS, drug-induced immunosuppression posttransplantation or congenital immunodeficiency (e.g., common variable immunodeficiency, ataxia-telangiectasia). EBV-SMT was first reported in the 1990s. The pathogenesis is disputed, but it is generally accepted that it begins with EBV infecting normal muscle which then proliferates in the setting of immunosuppression and ultimately undergoes neoplastic transformation. These tumors demonstrate a variable degree of local invasion but a low propensity for metastasis. The central nervous system (CNS) is a common site affected by EBV-SMTs—particularly in AIDS-related cases, but they have been reported at multiple sites including lung, liver, bone, kidney, intestines, stomach, genitourinary tract, and adrenals. The condition affects both children and adults with a slight female preponderance. We present the case of a previously healthy 8-year-old girl who presents with headache and vaginal bleeding. She underwent an uneventful resection of the skull base lesion via an extradural anterior petrosectomy or Kawase’s approach which was determined to be an EBV-SMT. Subsequent evaluation revealed systemic disease burden and a nonspecific CD4+ and CD8+ dysfunction. CT chest, abdomen, and pelvis revealed a left adrenal mass and multiple pulmonary nodules. The adrenal mass had avid uptake of FDG. She underwent left adrenalectomy and pathology was identical to that found for the skull base lesion.