Surgical treatment of tumor pathology of the parotid gland. Descriptive study of 263 parotidectomies

Introduction and objetive: Salivary tumors account for 3-10% of head and neck tumors, 75-80% being of parotid origin and mostly benign. Parotidectomy is a surgical technique that consists of exeresis of the parotid gland. There are various types; Superficial parotidectomy (PS), partial superficial parotidectomy (PSP), and total parotidectomy (PT). In the latter, since the facial nerve (FN) is not spared, complications are more frequent. Our objective is to analyze the outcome (recurrence rate and complica-tions) of parotidectomy as a surgical technique used in the management of parotid pathology, as well as to evaluate which complementary test is the most effective in the pre-surgical diagnosis of tumorous parotid pathology. Material and methods: We performed a retrospective study including 263 patients treated by SP or TP between January 2004 and December 2020 at the Fuenlabrada University Hospital. Demographic data, time of lesion evolution, complementary tests, surgical protocol and postoperative complications were recorded. The positive correlation between the pre-surgical tests performed (Fine needle aspiration (FNA), ultrasound, CT and MRI) and the definitive anatomopathological diagnosis obtained after exam-ining the surgical specimen is analyzed. The rate of paresis/facial paralysis and other complications is also described. Results: We included 263 patients treated by parotidectomy. The mean time of evolution of the parotid lesions was 15 months (SD 19.88). The sensitivity of FNA in our study was 68.7 %. Ultrasound was performed in 44.10% of patients (116/263), CT in 77.94% (205/263) and MRI in 15.20% (40/263), showing a positive correlation of 18.05%, 31.21% and 45%, respectively. The most frequent surgery was SP 43.3%, (114/263), closely followed by PSP (41.1%, 108/263) and finally the least common was TP (15.58%, 41/263). Benign tumors were more prevalent 84.79%, (223/263), with pleomorphic adenoma being the most frequent, 45.73% (102/223). Within the group of malignant tumors 15.20%, (40/263), the most common subtype was mucoepidermoid carcinoma (17.5%, 7/40) and metastases (17.5%, 7/40). Facial paresis, according to the House-Brackmann scale, was mild (grade I and II) and transient in most cases, appearing in 31.55%. After a mean follow-up period of 6 years, no recurrences were found in our study. Conclusion: In our sample, benign tumors represented the majority of parotid pathology. Within this group, pleomorphic adenoma was the most frequent. FNA was the complementary test with the best correlation with the definitive anato-mopathologic diagnosis, followed by MRI. Mild and transitory facial paresis (grades I and II) was the most common post-surgical complication.