Management of incidental discovery of microscopic squamous cell carcinoma in zones of osteoradionecrosis of the mandible.

OBJECTIVES: Osteoradionecrosis (ORN) of the mandible is a common complication of head and neck radiotherapy and often requires surgical treatment. Squamous cell carcinoma (SCC) can be exceptionally discovered within zones of ORN on histological examination of the operative specimen. The authors discuss the management of these lesions based on a short patient series. MATERIALS AND METHODS: This single-centre retrospective study was based on patients managed between 2012 and 2014 for ORN with incidental discovery of microscopic SCC. RESULTS: Five patients with incidental discovery of microscopic SCC in a zone of ORN of the mandible were included in this study. The mean time to onset of ORN after the end of radiotherapy for locally advanced SCC of the oral cavity or oropharynx was 42 months. Surgical treatment consisted of marginal or segmental mandibulectomy with free flap reconstruction. No recurrence was observed with a mean follow-up of 35 months [24-46]. CONCLUSION: The incidental discovery of microscopic SCC in a zone of ORN of the mandible is a rare event and has not been reported in the literature. Optimal management cannot be reliably defined due to the lack of data in the literature, but the present study supports careful histological examination of ORN specimens. Treatment must be as conservative as possible to avoid excessively invasive surgery.