Liposarcoma is a rare malignant mesenchymal tumour. Very few cases of retropharyngeal liposarcoma have been reported in the literature.

A 30-year-old woman with no notable history reported swallowing disorders for the past year associated with dysphonia. Nasal endoscopic examination demonstrated a tumour arising from the left lateral pharyngeal wall, ascending as far as the junction of the free margin of the epiglottis, aryepiglottic fold, and pharyngoepiglottic fold and obliterating the ipsilateral pyriform sinus with preservation of cord mobility. The rest of the physical examination was normal. The preoperative assessment was completed by gadolinium-enhanced MRI of the neck. Open surgery was performed. Definitive histological examination concluded on dedifferentiated liposarcoma with negative resection margins. Following staging chest computed tomography that did not reveal any metastases, the multidisciplinary consultation meeting decided to deliver adjuvant volumetric modulated arc therapy. No recurrence was observed nine months post-treatment.

Retropharyngeal liposarcoma is a rare tumour. The authors report the first case of a dedifferentiated histological subtype in this site. A review of the literature completes this case report by providing a description of prognostic factors and the various treatments.