Primary intracranial leiomyosarcoma presenting with massive peritumoral edema and mass effect: Case report and literature review.

Background: Primary intracranial leiomyosarcomas (LMSs) are unusual tumors of the central nervous system (CNS) affecting all age groups, and are recently, becoming more prevalent in immunosuppressive conditions such as in patients with human immunodeficiency virus (HIV) infection. However, only a few CNS LMS case reports exist in the English literature, on the occurrence of this rare entity in immunocompetent adults. Even, rarer is a purely intraparenchymal occurrence without any dural attachment in afflicted individuals. To the best of our knowledge, only four such cases have been reported in the literature until now. None of these cases were associated with marked peritumoral brain edema (PTBE) and mass effect as seen in our case and falsely suggesting an underlying glioma.

Case Description: A 45-year-old male patient, presented with headache, right-sided weakness and difficulties with speech over 4 months along with a single generalized tonic clonic seizure. Physical examination revealed mild to moderate papilledema, motor aphasia, and right-sided hemiparesis. Radiographic evaluation showed a large left temporo-parietal mass extending into the basal ganglia with intense heterogeneous contrast enhancement. There was marked perilesional edema and mass effect with midline shift. The patient underwent a left temporo-parietal craniotomy for subtotal resection of the tumor. The post-operative period was uneventful. Histopathology revealed a spindle cell tumor, which stained immunopositive for smooth muscle actin, vimentin, and S-100, yielding the diagnosis of LMS.

Conclusion: Primary intracranial LMS can rarely occur in immuno-competent adult patients and should be considered in the differential diagnosis of intraparenchymal lesions presenting with significant PTBE.