NUMERO: #20260031

Título: LOW-GRADE MAXILLARY OSTEOSARCOMA MIMICKING FIBROUS DYSPLASIA: A DIAGNOSTIC CHALLENGE IN FIBRO-OSSEOUS LESIONS

Nome do Apresentador: Carolina Oyarzo Zumelzu

Categoria do Trabalho: Pôster - Relato de Caso ou Série de Casos

Área Temática: Patologia Oral

Resumo: A 47-year-old woman presented with progressive swelling in the right posterior maxilla. CBCT revealed a mixed radiolucent-radiopaque lesion with cortical expansion, initially suggestive of fibrous dysplasia. An incisional biopsy was performed. Histopathological examination demonstrated a fibro-osseous proliferation composed of irregular trabeculae of immature woven bone, mild cytologic atypia, and low mitotic activity, findings that represented a significant diagnostic challenge. Immunohistochemical analysis showed positivity for MDM2 and CDK4, SATB2 expression, and a low Ki-67 index, supporting a low-grade malignant neoplasm. A final diagnosis of low-grade osteosarcoma (grade 1) was established, excluding fibrous dysplasia and trabecular ossifying fibroma. The patient underwent multidisciplinary head and neck evaluation and oncologic resection with clear margins. Periodic clinical and radiologic follow-up was implemented. This case highlights the critical importance of clinicoradiologic correlation and immunohistochemistry in distinguishing low-grade osteosarcoma from benign-appearing fibro-osseous lesions.

Autor 1:  Carolina Oyarzo Zumelzu

E-mail 1:  [email protected]

Autor 2:   Ana Niño Duarte

E-mail 2:  [email protected]

Autor 3 :  Olga Salinas Flores

E-mail 3:  [email protected]