Objective and importance: Gliosarcoma is a rare variant of glioblastoma multiforme that calls for the simultaneous presence of a gliomatous differentiation and a sarcomatous differentiation. A gliosarcoma with a sarcomatous differentiation that corresponds to a leiomyosarcoma has not previously been presented. This report presents an exceptional gliosarcoma with a prominent leiomyosarcomatous differentiation.

Clinical presentation: A 56 year-old man presented with weakness on the right arm and right leg that had progressed over one week. His physical examination revealed marked right-sided hemiparesis. A left-sided mass lesion was observed on magnetic resonance imaging that involved the surface of the parasagittal aspect of the left frontal lobe of the brain and that was associated with intense edema.

Intervention: The patient underwent a craniotomy with resection of the mass lesion and was diagnosed as having a gliosarcoma with a prominent leiomyosarcomatous differentiation. Based on the imminent risk of relapse, the decision was made to proceed with radiation therapy. He suffered a relapse at nine months following the diagnosis, declined salvage treatment and died within one month.

Conclusion: Although an exceptional gliosarcoma with a prominent leiomyosarcomatous differentiation might be treated with surgery and radiation therapy, the outcome remains dismal.

Keywords: Gliosarcoma, leiomyosarcomatous differentiation, surgery, radiation therapy