Maurizio Colecchia1, Alessia Bertolotti1, Biagio Paolini1, Francesca Giunchi2, Andrea Necchi3, Anna M Paganoni4, Costantino Ricci2, Michelangelo Fiorentino2, Gian P Dagrada1. 1. Department of Diagnostic Pathology and Laboratory Medicine, Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy. 2. Department of Pathology, Ospedale Maggiore and University of Bologna, Bologna, Italy. 3. Department of Medical Oncology, Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy. 4. Department of Mathematics, MOX-Modelling and Scientific Computing, Politecnico di Milano, Politecnico di Milano, Milan, Italy.
Abstract
AIMS: To investigate the morphological and molecular characteristics of Leydig cell tumours (LCTs) of the testis for the identification of cases that may metastasise. METHODS AND RESULTS: Six parameters for a predictive model of the metastatic risk were evaluated in 37 benign and 14 malignant LCTs of the testis [LCT Scaled Score (LeSS)]. The tumour size (benign LCTs, mean 13.3 mm; malignant LCTs, mean 44 mm) (P < 0.001) and five other parameters (infiltrative margins, necrosis, vascular invasion, mitotic count, and nuclear atypia) showed significant differences (Wilcoxon's test, P < 0.001). Eight metastatic LCTs and one benign LCT had infiltrative margins. Foci of coagulative necrosis occurred in 10 metastatic LCTs, whereas vascular invasion was identified in nine of 14 metastatic LCTs and none of 37 benign LCTs. Benign LCTs showed <2 mitoses/10 high-power fields (HPFs), whereas a high mitotic count (range, 3-50 mitoses/10 HPFs) was a feature of malignant LCTs. These parameters were selected by use of an inferential analysis based on univariate logistic regression models to develop a score. A LeSS of <4 correctly identified all histologically and clinically benign LCTs. A LeSS of ≥4 correctly identified all malignant LCTs. MDM2 and CDK4 immunostains were applied in all 51 cases: benign LCTs were negative; three of 11 malignant LCTs (27%) showed strong and diffuse immunopositivity and high levels of MDM2 and CDK4 amplification as determined with fluorescence in-situ hybridisation analysis and next-generation sequencing. CONCLUSION: We provide a new tool, the LeSS, for the prediction of malignant behaviour in LCTs.
AIMS: To investigate the morphological and molecular characteristics of Leydig cell tumours (LCTs) of the testis for the identification of cases that may metastasise. METHODS AND RESULTS: Six parameters for a predictive model of the metastatic risk were evaluated in 37 benign and 14 malignant LCTs of the testis [LCT Scaled Score (LeSS)]. The tumour size (benign LCTs, mean 13.3 mm; malignant LCTs, mean 44 mm) (P < 0.001) and five other parameters (infiltrative margins, necrosis, vascular invasion, mitotic count, and nuclear atypia) showed significant differences (Wilcoxon's test, P < 0.001). Eight metastatic LCTs and one benign LCT had infiltrative margins. Foci of coagulative necrosis occurred in 10 metastatic LCTs, whereas vascular invasion was identified in nine of 14 metastatic LCTs and none of 37 benign LCTs. Benign LCTs showed <2 mitoses/10 high-power fields (HPFs), whereas a high mitotic count (range, 3-50 mitoses/10 HPFs) was a feature of malignant LCTs. These parameters were selected by use of an inferential analysis based on univariate logistic regression models to develop a score. A LeSS of <4 correctly identified all histologically and clinically benign LCTs. A LeSS of ≥4 correctly identified all malignant LCTs. MDM2 and CDK4 immunostains were applied in all 51 cases: benign LCTs were negative; three of 11 malignant LCTs (27%) showed strong and diffuse immunopositivity and high levels of MDM2 and CDK4 amplification as determined with fluorescence in-situ hybridisation analysis and next-generation sequencing. CONCLUSION: We provide a new tool, the LeSS, for the prediction of malignant behaviour in LCTs.
Authors: Daniel M Berney; Ian Cree; Vishal Rao; Holger Moch; John R Srigley; Toyonori Tsuzuki; Mahul B Amin; Eva M Comperat; Arndt Hartmann; Santosh Menon; George J Netto; Mark A Rubin; Samra Turajlic; Maria R Raspollini; Satish K Tickoo Journal: Histopathology Date: 2022-07-01 Impact factor: 7.778