Clinicopathologic And Imaging Features Analysis Of Micro And Mini Parotid Gland Tumors

PART 1:Clinicopathologic analysis of micro and mini parotid gland tumorsObjective:To investigate the clinicopathological characteristics of micro and mini parotid gland tumors and to provide reference for their clinical diagnosis and treatment.Methods:Patients with parotid gland tumors treated in the department of oral and maxillofacial surgery,Peking University School and Hospital of Stomatology from December 2012 to April 2020 were selected.Relevant clinical data of patients with tumor diameter ≤20mm measured by preoperative CT were collected.The data was divided into diameter 11～20mm and≤l0mm two groups according to tumor diameter.The clinicopathological differences between two groups were statistically analyzed.Results:A total of 2067 patients with primary epithelial parotid tumors were collected,and 685 patients with tumor diameter ≤20mm were examined by CT,accounting for 33.1%.The ratio of male to female patients was 1:1.93,the average age was 45.3 years(12～83 years),and the median course of disease was 12 months(1 week～30 years).The ratio of benign to malignant was 12.7:1.The parotid gland mini tumors divided into diameter 11～20mm(n=611)and ≤l0mm group(n=74),the clinical characteristics comparison of the two groups of sex ratio on the age,course of disease,the ratio of benign to malignant tumors had no statistical difference(P>0.05).Fifty patients with malignant tumor were followed up with the median follow-up period of 39.5 months(1-91 months).Local recurrence occurred in 2 patients with one death.The overall 2-year survival rate was 93.7%and the 5-year survival rate was 89.3%.Conclusion:The majority of parotid gland mini tumors was benign lesion.There was a good prognosis for parotid gland mini carcinoma.Early surgical treatment was recommended for parotid gland micro tumors.PART 2:Imaging features analysis of micro and mini parotid gland tumorsObjective:To summarize the imaging features and location of micro and mini parotid gland tumors and provide reference for preoperative prediction.Methods:Patients with parotid gland tumors treated by surgery from December 2012 to April 2020 were selected.Relevant clinical data of patients with tumor diameter ≤20mm measured by preoperative CT were collected.The data was divided into Benign/Malignant two groups and diameter 11～20mm/≤10mm two groups.The differences of CT imaging features between the two groups were statistically analyzed;binary logistic regression analysis was done to investigate the imaging features differential of benign and malignant tumor.Results:A total of 685 patients with tumor diameter ≤20mm were collected and examined by CT,the following features showed a significant association with malignancy by univariate analysis:boundary,dominant density,shape,spiculation margin,CT value of plain and arterial phase.On logistic analysis,boundary,shape,spiculation margin were found to be independent predictors of malignancy(P<0.05).The imaging features comparison of diameter 11～20mm(n=611)and ≤10mm group(n=74)of shape、peripheral rim enhancement,CT value of arterial phase of benign to malignant tumors had statistical difference(P<0.05).Tumors of diameter ≤20 mm were located on deep lobe with 4.7%(32/685)and section I with 56.2%(385/685).There were no statistical differences by diameter and property of tumor(P>0.05).Conclusion:1.Parotid gland microcarcinoma appears several imaging features of typical malignant tumors as its size increases,the risk of microcarcinoma should be actively excluded through comprehensive clinical examination,needle biopsy and other imaging diagnostics.2.There was no significant difference in imaging findings between benign and malignant parotid gland tumors with diameter ≤10 mm.3.There were no obvious characteristics of distribution tendency of parotid gland tumors.