Ameloblastic fibrosarcoma in adolescence: A rare case of a malignant odontogenic tumor

A female patient, 15 years old, presented to the primary health unit with a complaint of vestibular and lingual swelling in the mandibular region, with a duration of 5 months. Imaging analysis revealed a destructive lesion with poorly defined margins. After an incisional biopsy, the lesion showed expansive and rapid growth. Microscopic analysis revealed an odontogenic tumor characterized by a biphasic composition of epithelial and mesenchymal components. The epithelial component showed unequivocal ameloblastoma-like features, without evidence of malignancy. In contrast, the spindle cell stroma exhibited nuclear atypia, occasional binucleation, a high mitotic index, and the presence of atypical mitotic figures. Notably, no evidence of hard tissue formation was found. The diagnosis was odontogenic sarcoma, ameloblastic fibrosarcoma subtype. The patient underwent surgical treatment in July 2024. Histopathological analysis of the surgical specimens confirmed the diagnosis with a positive result for the V600E somatic mutation in the BRAF gene. No sign of malignant cells was seen in the dissected lymph nodes. Rehabilitation included the placement of an adjustable titanium plate associated with a right platysma flap, with clinical follow-up for up to 12 months without signs of recurrence.