Meningeal malignant solitary fibrous tumor with multiple recurrence, extracranial extension, cervical lymph node metastases: case report and review of the literature.

Introduction: Solitary fibrous tumor (SFT) of the central nervous system (CNS) is a spindle cell neoplasm originating from mesenchymal tissue. SFT is prone to local recurrence or distant metastasis. The main sites of metastasis include the liver, lung, and bone. However, the tumor direct extracranial extension via natural skull base foramina to cervical region is rare.

Case Presentation: A 43-year-old male presented with an incidentally discovered left temporo-occipital region mass spanning the tentorium cerebelli identified during head and neck CT angiography, initially suspected as meningioma. The patient underwent gross total resection, with histopathological confirmation of a grade III malignant solitary fibrous tumor (WHO CNS 2007) originating from the left tentorium cerebelli. Immunohistochemical analysis demonstrated tumor cell positivity for CD34, vimentin, and Ki-67 (approximately 10%), while negative for EMA, PR, and P53. Subsequent disease progression manifested as multiple local recurrences with sacral and left pubic metastases. Multimodal management included adjuvant radiotherapy-Intensity-modulated radiation therapy (IMRT) and Gamma Knife radiosurgery(GKRS)-and concurrent bone-modifying agents (Ibandronate Sodium) for skeletal metastases. In June 2020 re-evaluation prompted by a palpable left neck mass revealed magnetic resonance imaging (MRI)-documented multifocal recurrence involving the left mastoid process and tentorium cerebelli, with extended through the jugular foramen into the left parapharyngeal space and involved the left cervical lymph nodes IMRT was performed with a prescribed dose of 54 Gy in 30 fractions. After completion of the treatment course, significant regression of most lesions was observed. However, the patient discontinued clinical follow-up after July 2021. Subsequent telephone contact confirmed expiration in September 2022 secondary to disease progression.

Conclusions: We report the first case of extracranial extension and cervical lymph node metastases from meningeal malignant SFT. This finding provides novel insights into the dissemination patterns of intracranial SFT. Surgical resection is the gold standard for the treatment. Postoperative radiotherapy (PORT) whether gross total resection (GTR) or subtotal resection (STR) may be the optimal treatment strategy, but PORT dose < 60 Gy with IMRT or marginal dose < 15 Gy with GKRS may be insufficient. Close and long-term follow-up, especially in the first five years after diagnosis, is essential to manage such patients because of high risk of recurrence and metastasis.