Influence of the patient`s sex and age, volumes of the salivary gland and pleomorphic adenoma on the tumor histological variants

Abstract

Aim: The purpose of the study was to identify the influence of the patient’s sex and age, the volumes of the salivary gland and pleomorphic adenoma on the histological variants of the tumor. Materials and Methods: The study included 21 women and 9 men with pleomorphic adenomas of the salivary gland. In 15 cases, a mesenchymal variant of pleomorphic adenoma was identified, in 5 cases – an epithelial variant, in 10 cases – a mixed variant. The average age of the patients was 39.7±2.9 years. Patients with pleomorphic adenomas underwent magnetic resonance imaging using a Siemens MAGNETOM Aera 1.5T device (Germany), during which three projections of the tumor and salivary gland were measured (antero-posterior, lateral, vertical) with subsequent calculation of their volumes, and then the ratios of these volumes. Classification trees were used to determine whether patients belonged to one of three variants of pleomorphic adenoma. The CART (Classification And Regression Tree) algorithm was used as a branching option. Stopping branching was carried out using the FACT (Fact-style direct stopping) method until each terminal (final) node of the tree does not contain incorrectly classified observations or when their number becomes less than a given proportion of the total group size (less than 5%). Determination of the structure and relationships between the tumor variants and such indicators as gender, age and radiological indicators (volume of the tumor, volume of the salivary gland, ratio of tumor volume to salivary gland volume) was carried out using correspondence analysis. Results: Epithelial variant of pleomorphic adenoma is more typical for women, and the mixed and mesenchymal variant is more common for patients of both sexes. The epithelial variant can develop in patients of any age, while the mixed variant occurs mainly in patients older than 41 years, and the mesenchymal variant – mainly in patients younger than 41 years. The ratio of the volume of the tumor to the volume of the salivary gland will be predominantly >0.17 in the epithelial variant of pleomorphic adenoma, predominantly ≤0.17 in the mesenchymal variant, and can take any value in the mixed variant. Conclusions: The authors conducted a study in order to identify the influence of sex, age of the patient, and the ratio of the volume of pleomorphic adenoma to the volume of the salivary gland on the histological variant of the tumor. The revealed data will be useful in the treatment and diagnostic process in patients with pleomorphic adenoma of the salivary gland.