Case Report: A case of early rapid recurrence of a primary intracranial alveolar soft part sarcoma with high proliferative activity and complex molecular variations

Alveolar soft part sarcoma (ASPS) is a rare type of soft tissue sarcoma; ASPS originating in the central nervous system is even rarer. Previous literature has generally described it as having an indolent course with a favorable prognosis following surgical resection. This report presents a case of a 31-year-old woman with primary intracranial alveolar soft part sarcoma (PIASPS) that exhibited the opposite characteristics, demonstrating high invasiveness. The patient underwent gross total resection during the initial surgery, and postoperative histopathological examination and immunohistochemistry confirmed the diagnosis of PIASPS. Rapid local recurrence occurred just over two months after surgery; the tumor exhibited abnormally high proliferative activity, with an initial Ki-67 index of approximately 65%, which rose to 75% following recurrence. Molecular testing also revealed a complex mutation profile, including a BRAF p.V600E mutation, a TP53 p.D281E missense mutation, a TERT promoter mutation, an NBN truncating mutation, an HGF nonsense mutation, and an RPSAP52-HMGA2 fusion; these molecular events may have contributed to the rapid tumor recurrence, although their individual and combined effects require further functional validation. Following recurrence, the patient underwent a second surgery, followed by adjuvant radiotherapy and concurrent oral anlotinib; however, the patient died two months following the completion of radiotherapy, with an overall survival of eight months. Characterized by rapid early postoperative recurrence, sustained high proliferative activity, and complex molecular features, this case challenges the traditional perception of PIASPS as an indolent tumor. This case suggests that a high Ki-67 index combined with molecular subtyping may help identify potentially aggressive subtypes; its value in guiding decisions regarding adjuvant therapy may be further explored in future studies.