AB124. SOH24AB_133. Diagnostic superiority of MRI in evaluating the presence of bone invasion in head and neck cutaneous squamous cell carcinoma

Background: In cutaneous squamous cell carcinoma (cSCC) of the head and neck, accurate evaluation of bone invasion is imperative to guide ablative and reconstructive surgical planning and provide accurate pre-operative counselling for patients. Methods: We present the case of an 88-year-old male with one year history of a poorly differentiated 8 cm × 6 cm ulcerated cSCC affecting the forehead. Results: Computed tomography (CT) suggested direct adherence of the mass to the outer table of the frontal bone (FB). A magnetic resonance imaging (MRI) brain was performed to assess for invasion of the tumour into the adjacent critical structures. A Sagittal T1 post contrast MRI brain showed invasion through the outer table however the inner table was not breached and no adjacent critical structures were infiltrated. Tumour ablation and reconstruction was performed by a two team (plastic surgery and neurosurgery) approach. Final histology demonstrated infiltrative SCC involving the skin and underling bone. The radial margins were clear while bony margin was 1 mm from deep margin. At latest follow-up 2 years post procedure, the patient remains disease free. Conclusions: CT provides a valuable initial assessment for patients presenting with cSCC of the head and neck. However, in cases of bony abutment on radiographs or clinically fixed masses, MRI is a superior imaging modality in accurately identifying the extent of bony invasion enabling procedural planning and patient consent.