Surgical management of rare lesions in the parapharyngeal space

Lesions in the parapharyngeal space (PPS) are diverse. Management strategies for commonly seen PPS lesions (i.e., pleomorphic adenoma and schwannoma) have been widely accepted while less well defined for more rare PPS tumors. The purpose of this study was to retrospectively review rare entities of the PPS, and to evaluate the role of minimally invasive surgical approaches for management of rare entities in this complex region.

From Jan 1, 2010 to Dec 31, 2021, 328 patients who harbored PPS tumors were included and retrospectively reviewed. Those patients with a common PPS tumor (pleomorphic adenoma and schwannoma) were excluded. Fifty-one patients with rare PPS entities were included (42 patients with benign lesions and 9 patients with malignancies). Demographics, pathological outcomes, and treatment strategies for patients with rare entities were evaluated and retrospectively reviewed.

A minimally invasive surgical approach (i.e., transoral endoscopic approach, or as a combined approach) was adopted in 52.4% of cases for extirpation of benign cases in the PPS. For malignancies in the PPS, the transoral endoscopic approach was applied in 66.7% of malignant cases such as metastatic lymph node dissection or biopsy. Moreover, the traditional approach (i.e., transcervical transparotid approach with or without mandibulotomy) accounted for 47.6% and 33.3% for management of complex benign and malignancies in the PPS, respectively.

Rare entities arising in the PPS are diverse. An endoscopic transoral approach can be appropriately utilized in more than half of rare entities including both the benign tumors and malignancies in the PPS.