High-grade astrocytoma with piloid features: a case report of comprehensive management.

High-grade astrocytoma with piloid features (HGAP) is a rare and recently defined nervous system tumor. To date, clinical reports and therapeutic experience regarding HGAP remain scarce. Herein, we describe a 35-year-old female patient presenting with progressive numbness in the right neck and shoulder region for 2 months. Imaging examinations revealed an intramedullary tumor at the cervicomedullary junction. Histopathological analysis confirmed anaplastic glioma, and DNA methylation profiling established the diagnosis of HGAP. The patient subsequently underwent surgical resection combined with adjuvant radiotherapy and concomitant temozolomide chemotherapy. This tumor commonly occurs in the posterior cranial fossa of adults. In this report, we aim to present the clinical course of an extremely rare case of high-grade astrocytoma with piloid features (HGAP) that developed radiological progression in the early postoperative period, and to explore the clinical significance of this atypical manifestation.