Epstein-Barr virus-associated primary intracranial leiomyosarcoma in an immunocompetent patient: illustrative case

BACKGROUND Primary intracranial leiomyosarcomas (PILMSs) are extremely rare tumors arising from smooth muscle connective tissue. PILMSs have been shown to be associated with Epstein-Barr virus (EBV). Thus far, EBV-associated PILMS has been exclusively described in immunocompromised patients. OBSERVATIONS A 40-year-old male presented with a 2-year history of left-sided headaches, nausea, and vomiting. Magnetic resonance imaging demonstrated a large, heterogeneously enhancing, lobulated, dura-based mass arising from the left middle cranial fossa with associated edema and mass effect. The patient underwent an uncomplicated resection of suspected meningioma; neuropathology revealed the exceedingly rare diagnosis of EBV-associated PILMS. Follow-up testing for human immunodeficiency virus (HIV) and other immunodeficiencies confirmed the patient's immunocompetent status. LESSONS Primary intracranial smooth muscle tumors are often misdiagnosed as meningiomas due to their similar appearance on imaging. PILMSs have a poor prognosis and gross total resection is the mainstay of treatment in the absence of clear recommendations for management. Prompt diagnosis and resection are important; therefore, these tumors should be included in the differential of dura-based tumors, especially among immunocompromised patients. Although EBV-associated PILMSs usually occur in immunocompromised individuals, their presence cannot be ruled out in immunocompetent patients.