Odontogenic myxoma with rare sunburst periosteal reaction: report of two cases and review of the literature.

Odontogenic myxoma (OM) is a benign tumor originating from odontogenic ectomesenchyme. While this tumor displays imaging variability, the sunburst appearance is uncommon and can resemble malignant lesions. In this report, we present two cases of OM exhibiting an imaging sunburst appearance, besides a literature review. A 35-year-old woman and a 21-year-old woman presented with mandibular swelling. Imaging exams revealed extensive radiolucent/hypodense images, with the presence of a sunburst periosteal reaction. The main diagnostic hypothesis for both cases was osteosarcoma. Incisional biopsies were performed, with definitive diagnosis of OM. The first patient underwent simple surgical excision, while the second underwent en bloc resection. Neither patient experienced recurrence during the follow-up period of three and one year after treatment. Odontogenic myxoma should be considered in the differential diagnosis of jaw lesions presenting a sunburst periosteal reaction, as this atypical imaging pattern may mimic aggressive or malignant conditions.