Usefulness of apparent diffusion coefficient values and magnetic resonance imaging histogram analysis for identifying histological types of preoperative testicular tumors

Background Only a few studies have performed histogram analysis for the differential diagnosis of testicular tumors. Therefore, the aim of this study was to evaluate the ability of magnetic resonance imaging (MRI), including diffusion-weighted imaging with apparent diffusion coefficient values, to differentiate between the histological types of testicular tumors. Methods Of the 156 testicular tumors diagnosed at our hospital between January 2010 and July 2023, 65 cases diagnosed with MRI were included. Tumors were categorized as seminoma, non-seminoma, and malignant lymphoma. Apparent diffusion coefficient values were calculated and analyzed using the ratio to non-tumor testes and histograms according to tumor subtypes. Results Among the 65 cases, 46, 14, and 5 entailed seminomas, non-seminomas, and malignant lymphomas, respectively. The apparent diffusion coefficient value ratio of seminomas was significantly higher than that of malignant lymphomas (p = 0.013). Additionally, the apparent diffusion coefficient value ratio of non-seminomas was significantly higher than that of seminomas and malignant lymphomas (p = 0.0013 and p < 0.001, respectively). Malignant lymphomas had significantly higher values of kurtosis and skewness on apparent diffusion coefficient histograms than seminomas. Non-tumor testes and non-seminomas had significantly higher values of kurtosis and skewness than malignant lymphomas and seminomas. Conclusions The present results demonstrate the efficacy of MRI with ADC values and histograms in the differentiation of testicular tumor subtypes. A pre-operative diagnosis of testicular tumor subtypes may result in more effective management of testicular tumors, including pre-operative counseling and early treatment planning.