Intraosseous Solitary Fibrous Tumor of the Maxilla: A Report of an Unusual Case.

Solitary fibrous tumor (SFT) is a mesenchymal fibroblastic neoplasm initially described in the pleura and subsequently reported in other anatomical sites, primarily affecting the extremities and deep soft tissues. It is driven by the NAB2::STAT6 fusion and presents with nonspecific clinical features, necessitating thorough histopathological evaluation and the use of an immunohistochemical panel for diagnosis. SFT is extremely rare in the maxillofacial region and even more uncommon when involving bone. This case report describes a 31-year-old male who presented with a slow-growing, progressive, painless, deforming mass in the left posterior maxillary region, with 14 months of evolution. After clinical and imaging evaluation, an incisional biopsy was performed. Histopathological and immunohistochemical studies confirmed SFT. Surgical excision of the lesion with preservation of oncologic margins was performed, achieving complete tumor removal. This case highlights an unusual presentation of SFT in the maxilla of a young patient. Diagnosis requires correlation of clinical, imaging, and histopathological findings, with immunohistochemistry using specific markers being essential. Complete surgical resection remains the treatment of choice, and prolonged follow-up is recommended due to the risk of local recurrence, contributing to the understanding of this rare entity in the maxillofacial region.