Transformation of a low-grade glioma into a glioblastoma along with the development of lung and mediastinal lymph node metastases after repeated craniotomy: A case report.

Extracranial metastasis of glioma is extremely rare. Herein, we report a case of glioblastoma that originated and showed stepwise malignant transformation from a low-grade glioma (LGG) along with the presence of lung and mediastinal lymph node metastases after repeated craniotomy. A 30-year-old man presented with hemoptysis. Thoracic computed tomography revealed a space-occupying lesion in the right upper lung with mediastinal nodal and metastases in both lungs; lung cancer was suspected. The patient's medical history showed that he had undergone craniotomy three times in 7 years for a primary LGG disease relapse, and stepwise malignant-transformed high-grade glioma (HGG). However, brain magnetic resonance imaging did not reveal any relapse of intracranial tumors. The diagnosis of extracranial metastatic glioblastoma was confirmed using the morphology and staining results for specific immunohistochemistry markers using the specimen obtained via endobronchial ultrasound transbronchial needle aspiration. Subsequently, the patient received a combination of systemic and local treatments; however, he died of massive hemoptysis after 6 months. The survival time of this glioma patient improved after transformation and metastasis. Detailed descriptions will help us understand the biological behavior of glioma, but more studies are needed to confirm the complex mechanism of extracranial metastasis.