Preoperative assessment of malignant skin tumor thickness using 7.5 MHz and 14 MHz ultrasound: correlation with histology

Abstract

a. Aim The aim of this study was to compare the accuracy of 7.5 MHz and 14 MHz ultrasound with histology for the preoperative assessment of malignant skin tumor thickness. b. Materials and Methods Retrospective analysis of 60 malignant skin tumors was performed. Preoperative vertical tumor thickness of 30 skin tumors (21 melanomas and 9 basal cell carcinomas) was assessed by 7.5 MHz ultrasound scan, and tumor thickness of other 30 skin tumors (14 melanomas and 16 basal cell carcinomas) was assessed by 14 MHz ultrasound scan. The correlation between sonometric and histometric tumor thickness was estimated. Nonparametric Wilcoxon test and Spearman’s correlation coefficient were used for statistical analysis. c. Results High correlation between sonometry and histomery was computed using 7.5 MHz as well as 14 MHz ultrasound scans (r = 0.885 and r = 0.832, respectively, p < 0.01). Using 7.5 MHz and 14 MHz ultrasound, tumor thickness was determined for melanomas (r = 0.881 and r = 0.800) and for basal cell carcinomas (r = 0.938 and r = 0.717). No statistically significant difference between tumor thickness correlations was noticed (p < 0.01). d. Discussion Both 7.5 MHz and 14 MHz ultrasound showed good accuracy in comparison with histology for preoperative assessment of malignant skin tumor thickness. It is a reliable, noninvasive method and can be useful to predict the surgical planning of melanomas, to avoid reexcision and to choose the optimal treatment of basal cell carcinomas.