NCMP-16. A CASE OF WIDESPREAD EXTRACRANIAL METASTASES FROM A GLIOSARCOMA

Abstract

Abstract BACKGROUND: Glioblastoma (GBM) with sarcomatous features (gliosarcoma) accounts for 2-8% of all glioblastomas1,2, characterized by a biphasic histopathology pattern consisting of glial and sarcomatous components. While GBMs generally do not metastasize outside the central nervous system (CNS), GS has been associated with extracranial metastases in up to 11% of cases3. Case presentation: A 58-year-old right-handed woman with a GBM presented to our institution for a second opinion. She was initially diagnosed 18 months prior and had received radiotherapy with concurrent temozolomide. Her adjuvant temozolomide was discontinued due to rash, and she started on bevacizumab. Her tumor progressed and she sought additional treatment options. On her initial presentation, she was tachycardic with leukocytosis, prompting admission. A chest CT showed thoracic adenopathy, multiple bilateral pulmonary nodules, and a large left malignant pleural effusion. Bronchoscopy revealed spindle cell sarcomatoid neoplasm raising the possibility of metastasis from a CNS primary tumor. Additionally, the patient endorsed development of subacute radicular pain in her bilateral lower extremities as well as weakness. MRI of total spine revealed multilevel osseous and epidural lesions, infiltrating the paraspinal muscles and thickening of cauda roots with concern for leptomeningeal disease. A subsequent PET-CT showed increased FDG avidity in these lesions. Reevaluation of the initial CNS pathology confirmed the presence of mesenchymal/sarcomatous differentiation, consistent with a diagnosis of GS. As confirmed by autopsy, the patient eventually passed away due to widespread and metastatic disease. Discussion: While GBM rarely metastasizes outside the CNS, GBM with sarcomatous features are more likely to exhibit extracranial metastasis. Our patient had widespread involvement, including the lungs, heart, liver, omentum, and bone. Metastasis was thought most likely once EBUS of the lung returned with sarcomatous features. Clinicians should therefore maintain a high suspicion for metastases when dealing with patients diagnosed with GS.