Clinicopathologic Analysis Of Parotid Gland Tumors Of Chaoshan Area

Background and objectiveParotid gland tumor is the most common tumors of the head and neck, of which the vast majority is epithelial tumor; mesenchymal tumor is rare. Histopathologic types of epithelial tumors are very complex, and different literatures have different views in the incidence, diagnosis, treatment and prognosis of different types of parotid gland tumor. The location of Chaoshan area of China is special, which is a relatively closed costal area. The local customs, practices and eating habits are unique,and some diseases such as nasopharyngeal carcinoma is also obvious regional characteristics in this area. But so far, there hasn't been any literature to study the histopathology constitution of the parotid gland tumors in Chaoshan area. In this paper, the retrospective analysis was made to study the constitution and histopathologic features of parotid gland tumors in Chaoshan areas of China. The diagnostic value of applying the frozen section in parotid surgery was discussed. Our purpose is to provide the helpful data for the clinical diagnosis and treatment of the patients with parotid gland tumor.MethodsIn our study, 306 patients with parotid gland tumor were collected from the First Affiliated Hospital of Shantou University Medical College (SUMC) and the Second Affiliated Hospital of SUMC during the periods from January 2002 to December 2009. All patients were from Chaoshan area, and underwent the initial treatment,and their diagnoses were confirmed by postoperative paraffin section. The distribution of age, gender and each pathologic type of the patients with parotid gland tumors were analyzed and statistics. Distribution of Warthin tumor and pleomorphic adenoma in both hospital and origin regions of the patients constitution of Warthin tumor and pleomorphic adenoma of the both hospital were analyzed. We also analyzed the intraoperative frozen section diagnosis accuracy. Results1. The peak age of patients with parotid gland tumors in Chaoshan area was 50 to 59 years old, followed by 40 to 59 years old, and these tumors might occur at any age. The ratio of male to female patients with these tumors was 2:1, with 7.05:1 as the ratio of benign to malignant parotid gland tumors.2. The peak age of benign parotid gland tumors in Chaoshan areas was 50 to 59 years old, followed by 40 to 59 years old, with 2.23:1 as the ratio of male to female patients. Among younger patients (0 to 39 years old), there were more women than men, while there were more men than women in elder patients (above 40 years old).3. The peak age of malignant parotid gland tumors in Chaoshan areas was 60 to 69 years old, followed by 50 to 59 years old, with 1:1 as the ratio of male to female patients. There was no significant difference in sex ratio among young patients (0 to 49 years), while there were more males than females in older patients (50 to 69 years old).4. The pathological type of parotid gland tumor was variform. There were 16 types of epithelial tumors and 6 types of non-epithelial tumors. The epithelial tumors include 6 types of benign tumors and 10 types of malignant tumors.5. The most common benign parotid gland tumor was Warthin tumor, followed by pleomorphic adenoma. The most common malignant tumor of the parotid gland was mucoepidermoid carcinoma, followed by adenoid cystic carcinoma.6. In the distribution of Warthin tumor and pleomorphic adenoma,and origin regions of the patients, there was significant difference between the First Affiliated Hospital and the Second Affiliated Hospital of SUMC.7. The diagnostic accuracy of perioperative frozen section of parotid gland tumor was 91.89%, with 96.30% in benign tumors and 80.00% in malignant tumors;the diagnostic accuracy was higher than the rate of clinical diagnosis.Conclusions1. In Chaoshan area of China, parotid gland tumors usually occurrd in the elderly, with more benign than malignant tumors, and more men than women. There were more male than female patients with benign parotid gland tumors in younger age groups, while the opposite occurred in elder patients. There was not significant difference in the sex ratio of young patients with malignant parotid gland tumors, while there were more men than women in elder patients.2. Warthin tumor was the most common one of the benign parotid tumors in Chaoshan area of China, rather than the pleomorphic adenoma in other areas of China.3. There was significant difference in distribution of Warthin tumor and pleomorphic adenoma between the First Affiliated Hospital and the Second Affiliated Hospital of SUMC, and so was the origin regions of the patients between these two hospitals. One of main reasons for the significant difference in the distribution was that the patients come from different origin regions.4. Intraoperative frozen section diagnosis is of great value in modification and identification of operation program and should be used as one of common methods in the parotid surgery.