Giant deep lobe parotid gland pleomorphic adenomas involving the parapharyngeal space – external versus transoral approach

Background Giant pleomorphic adenomas extending to the parapharyngeal space are rare tumours and no clear recommendations regarding the optimal surgical approach (external versus transoral approach) for resection of parapharyngeal pleomorphic adenomas exist. Based on our own results and experiences we discuss the two ways of surgical approach for resection of giant pleomorphic adenomas involving the parapharyngeal space.

Materials and methods 7 cases of giant pleomorphic adenoma involving the parapharyngeal space were operated between 2012 and 2020. 5 patients were treated by an external approach and 2 patients initially received transoral surgery. However, in the course of the surgery an additional external approach was necessary in order to avoid a lesion oft he facial nerve. We assessed the distance of the tumor from the main branch of the facial nerve correlating with the risk of a postoperative facial nerve deficit caused by an isolated transoral approach.

Results A complete resection of the pleomorphic adenoma of the parapharyngeal space could be achieved in all cases by an external approach. In both cases with an initial transoral approach a safe tumor resection with definite identification of the main branch of the facial nerve was not possible. Therefore, an additional external approach was necessary. In all 7 cases the giant pleomorphic adenoma of the parapharyngeal space was in close contact with the main branch of the facial nerve.

Conclusion Especially for giant pleomorphic adenomas of the parapharyngeal space with a wide lateral extent a high risk for facial nerve injury occurs using an isolated transoral approach. To reduce this risk an external approach for resection of pleomorphic adenomas of the deep parotid lobe is recommended.

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Artikel online veröffentlicht:
12. Mai 2023