Primary intracranial leiomyosarcoma in an immunocompetent patient: Case report with emphasis on imaging features.

Primary intracranial leiomyosarcoma (LMS) is an extremely rare tumor in the central nervous system (CNS), and usually seen in immunocompromised individuals. Only a few cases of primary intracranial LMS have been documented in the literature and no study focused on their MRI findings. We reported a case of primary intracranial leiomyosarcoma in a immunocompetent patient and review its imaging features. A 20-year-old female was admitted to our hospital, complaining with nausea, weight loss and progressive headache in recent 2 years. The magnetic resonance imaging scan of the brain revealed a large well-defined extra-cerebral mass adherent to left temporal meninges. The mass was iso-intense on T1-weighted images (T1WI), lightly iso to hypointense on T2-weighted images (T2WI) and enhanced uniformly with contrast medium. The preoperative diagnosis is meningioma. A left craniotomy was performed for the complete resection of the mass. The lesion was diagnosed via surgical histopathology and immunochemistry as leiomyosarcoma. No evidence of recurrence and complications were found in the following 13 months. Primary intracranial leiomyosarcoma which has some special MR imaging features should be considered in the differential diagnosis of intracranial tumor.