Differential diagnostic value of tumor morphology, long/short diameter ratio, and ultrasound gray-scale ratio for 3 parotid neoplasms

Abstract

The objective of this study was to evaluate the value of tumor morphology, long-to-short diameter ratio (L/S), and ultrasound gray-scale ratio (UGSR) in the differential diagnosis of 3 parotid neoplasms. Preoperative ultrasound images of 17 patients with a malignant tumor (MT), 48 patients with pleomorphic adenoma (PA), and 39 patients with adenolymphoma (AL) were analyzed for imaging features and gray-scale histograms. Tumor morphology, L/S, and UGSR of MT, PA, and AL were compared. Receiver operating characteristic analysis of area under the curve (AUC), sensitivity, and specificity were used to measure the differential diagnostic efficacy of L/S, UGSR, and both combined with tumor morphology. Morphologic features, L/S, and UGSR differed significantly in various pairwise comparisons of the 3 tumor types. Acceptable discrimination was detected between MT and AL with UGSR alone (AUC=0.771) and between PA and AL with L/S and UGSR combined (AUC=0.741). The combination of tumor boundary with UGSR yielded excellent discrimination between MT and PA (AUC=0.853) and between MT and AL (AUC=0.885), with sensitivity and specificity values greater than 0.800. These ultrasound parameters, alone or in combination, can provide a method for accurate presurgical differential diagnosis of parotid tumors.