Minimally Invasive Surgery for Retropharyngeal Infiltrative Intramuscular Lipoma: Report of a Case Treated Using a Combined Transoral and Transnasal Approach

Retropharyngeal infiltrative intramuscular lipomas are rare, and only 2 cases have been reported. Surgical resection is technically challenging owing to anatomical constraints, with no established optimal approach. Furthermore, the risk of recurrence is high. Herein, we report a novel, minimally invasive, and effective surgical approach for retropharyngeal infiltrative intramuscular lipoma. A 75-year-old woman presented with snoring as the chief complaint. Magnetic resonance imaging revealed a 52 × 38 mm lipoma in the retropharyngeal space with infiltration into the longus capitis muscle. A combined transoral and transnasal approach using existing endoscopic instruments enabled complete tumor resection with enhanced visualization and minimal invasiveness. Postoperative histopathological examination confirmed the diagnosis of infiltrative intramuscular lipoma. One year postoperatively, no recurrence was observed, and the patient will continue long-term follow-up. Infiltrative intramuscular lipomas are associated with a high risk of recurrence, and wide excision of the infiltrated area is required to achieve clear margins. Therefore, a surgical approach that balances complete resection with minimal invasiveness is required. The combined transoral and transnasal approach offers a cost-effective, minimally invasive, and precise method for resecting retropharyngeal infiltrative intramuscular lipomas.