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

Abstract

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.

Keywords: Epstein-Barr virus; immunocompetent; primary intracranial leiomyosarcoma; sarcoma; smooth muscle tumor.

FIG. 1.

Coronal T1-weighted MRI with gadolinium (A) and axial T2-weighted MRI (B) demonstrate an avidly enhancing mass measuring 5.8 × 5.5 × 4.4 cm (anteroposterior × transverse × craniocaudal). There is a central area of hypo-enhancement compatible with necrosis, mass effect on the temporal lobe and brainstem, and a 7-mm rightward midline shift. Axial (C) and three-dimensional (D) reconstruction of CT angiography demonstrates hypervascularity of the tumor as well as an association with the left middle cerebral artery.

FIG. 2.

Intraoperative photograph demonstrates resection cavity after GTR of the lesion using a left frontotemporal craniotomy with removal of the sphenoid wing and drilling of the anterior clinoid. The large tumor was abutting the ipsilateral frontal (F) and temporal (T) lobes and was entering the sylvian fissure (*). A major arterial feeder along the base of the middle fossa supplied the tumor, and the intraoperative photograph shows the result of its coagulation (arrow). Doing so early in the surgery allowed for maximal safe resection with minimal blood loss and brain manipulation.

FIG. 3.

Photomicrographs of the tumor with hematoxylin and eosin (H&E) staining (A and B) demonstrate a non-meningothelial mesenchymal tumor with extensive smooth muscle differentiation. The tumor is composed of intersecting fascicles of spindle cells with ample eosinophilic cytoplasm, elongated blunt-ended nuclei, and mild cytological atypia. Prominent lymphocytic infiltrates composed primarily of T cells were present focally (B). Original magnification ×100 (A) and × 200 (B).

FIG. 4.

Immunohistochemical stains showed that the tumor was diffusely positive for h-caldesmon (A, original magnification ×200). In situ hybridization for EBER was strongly positive in tumor nuclei (B, original magnification × 100).