Primary intracranial leiomyosarcoma arising from the dura
Primary intracranial leiomyosarcoma are extremely rare tumors with only 15 cases reported in the literature [3-6]. Most reported cases represent metastatic disease from other primary sites such as gastrointestinal tract, uterus and subcutaneous tissue ; the primary tumors are postulated to arise from the mesenchymal cells of dura matter or the cerebral blood vessels. All possible occult primary sites were excluded by whole body imaging including PET scan. The common diagnostic considerations for dura-based mass in a middle-aged male include meningioma, hemangiopericytoma, primary melanocytic tumors, metastatic carcinoma/sarcoma and a poorly recognized entity- meningeal sarcoma. Besides the distinctive morphological features including plump spindle cells with abundant eosinophilic cytoplasm, immunoreactivity for muscle markers (SMA and desmin) confirmed the myoid nature of the neoplasm. Earlier reported cases suggest an association between AIDS, EBV and leiomyosarcoma ; however, such an association was lacking in the present case. Specific serologic tests performed during the pre-operative work up were negative and the immunohistochemistry performed for EBV nuclear antigen was negative.
Primary intracranial leiomyosarcoma, unlike glial tumors, have a metastatic risk outside the central nervous system. Metastatic disease has been reported in up to 40% of patients and is associated with a poor prognosis . Additionally, these are known to disseminate to neuraxis besides spread to lungs and bone hence, necessitating both neuraxis and whole-body imaging (computed tomography and PET scan) along with lumbar cerebrospinal fluid cytology at diagnosis with regular follow-up .
The prognosis and clinical behavior of primary intracranial leiomyosarcoma remains uncertain both due to disparities in treatment offered and limited experience in treating such lesions owing to rarity. Nevertheless, the mainstay of treatment for all age groups appears to be maximal safe surgical resection. Administration of chemotherapy and radiotherapy may improve the outcome.
Contributed by Vikram Singh, MD, Kirti Gupta, MD, Apinder Preet Singh, MS, M Ch, Pravin Salunke, MS, M Ch