AUTHOR=Riva Federica , Vari Sabrina , Onesti Concetta Elisa , Covello Renato , Scuderi Silvia , Ceddia Serena , Fiore Maria Rosaria , Anelli Vincenzo , Strippoli Sabino , Ferraresi Virginia 

TITLE=Case Report: Malignant transformation of maxillary giant cell tumor of bone from EURACAN reference center

JOURNAL=Frontiers in Oncology

VOLUME=Volume 15 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1604056

DOI=10.3389/fonc.2025.1604056

ISSN=2234-943X

ABSTRACT=Giant cell tumor of bone (GCTB) is a benign but locally aggressive neoplasm that can rarely undergo malignant transformation, with a poor prognosis. The most frequent histotypes of the sarcomatous transformation of GCTB are osteosarcoma, fibrosarcoma, and undifferentiated pleomorphic sarcoma, and the treatment approach mirrors that of high-grade sarcomas. This case report describes the malignant transformation of a maxillary GCTB treated with standard systemic treatments for bone tumors and local treatment, resulting in a progression of disease until the patient’s death. Nevertheless, a marked radiological and clinical response was achieved with local carbon ion therapy. This case highlights the diagnostic and therapeutic challenges of malignant transformation of GCTB, emphasizing the importance of a multidisciplinary approach at specialized centers and the potential role of local therapies in selected cases.