[Benign deep lobe parotid tumors: classification in association with localization and surgical approaches].

Purpose: Benign deep lobe parotid tumors(BDLPT) exhibit a wide range of clinical and imaging features, which closely correlated with the selection of appropriate surgical approaches. This study was aimed to explore variations in surgical management.

Methods: Seventy-five patients with primary BDLPT who underwent surgery in Peking University School and Hospital of Stomatology from August 2014 to August 2020 were included. The imaging data of all cases were retrospectively evaluated. BDLPTs were divided into four types according to the anatomical relationship between the tumor and various structures, and the surgical treatment of each type of tumor was studied. SPSS 24.0 software package was used for statistical analysis.

Results: TypeⅠBDLPT(14/75, 18.7%) was located entirely medial to the ramus and the stylomandibular space, with growth extending towards the parapharyngeal space. Type Ⅱ BDLPT(19/75, 25.3%) resided within the retromandibular space, bounded by the ramus, stylomandibular space, mastoid, and retromandibular vein. Type Ⅲ BDLPT(27/75, 36.0%) exhibited an expansive growth pattern, extending from the retromandibular vein to the parapharyngeal space while traversing the stylomandibular space. Type Ⅳ BDLPT(15/75, 20%) was situated inferior to the ear lobe, deep to the facial nerve and retromandibular vein. Transmandibular approach was predominantly employed in type I cases (10/14). Type Ⅲ cases utilized transparotid (14 cases), transmandibular(11 cases), and combined transparotid-transmandibular (2 cases) approaches. Type Ⅱ and Ⅳ cases involved transparotid approaches with concurrent parotidectomy.

Conclusions: The classification of BDLPT offers valuable insights and practical guidance for preoperative treatment planning.