Primary alveolar soft part sarcoma arising from the cerebellopontine angle

Alveolar soft part sarcoma (ASPS), a rare soft tissue malignant neoplasm, frequently metastasizes to the brain. However, primary intracranial ASPS is extremely rare. We present a case of primary intracranial ASPS arising from the cerebellopontine angle (CPA) without demonstrable systemic lesions. An 11-year-old girl presented with a recurrent tumor in the right CPA after a partial resection and radiation therapy (RT). Near-total resection with a minimal tumor left in the jugular foramen was performed. The pathological diagnosis was ASPS. There was no evidence of primary extracranial tumors. She underwent adjuvant chemotherapy and gamma knife surgery. At 29 months after the second surgery, magnetic resonance imaging revealed multifocal enhancing lesions at the prepontine cistern, right CPA and medulla oblongata, despite intensive treatment. However, extracranial metastasis was not noted. This case suggested a poor outcome of primary intracranial ASPS, similar to extracranial ASPS.