Since the last World Health Organization (WHO) Classification scheme for tumours of the urinary tract and male genital organs, there have been a number of advances in the understanding, classification, immunohistochemistry, and genetics of testicular germ cell tumours. The updated 2016 draft classification was discussed at an International Society of Urological Pathology (ISUP) Consultation on Testicular and Penile Cancer. This review addresses the main updates to germ cell tumour classification. Major changes include a pathogenetically derived classification using germ cell neoplasia in situ (GCNIS) as a new name for the precursor lesion, as well as distinction of prepubertal (non-GCNIS-derived) from postpubertal-type tumours (GCNIS-derived), acknowledging the existence of rare benign prepubertal-type teratomas in the postpubertal testis. Spermatocytic tumour is adopted as a replacement for spermatocytic seminoma to avoid potential confusion with the unrelated usual seminoma. The spectrum of trophoblastic tumours arising in the setting of testicular germ cell tumour continues to expand, to include epithelioid and placental site trophoblastic tumours analogous to those of the gynecologic tract. Currently, reporting of anaplasia (seminoma or spermatocytic tumour) or immaturity (teratoma) are not required, as these do not have demonstrable prognostic importance. In contrast, overgrowth of a teratomatous component (somatic-type malignancy) and sarcomatous change in spermatocytic tumour indicate more aggressive behavior and should be reported. This article is protected by copyright. All rights reserved.
Histopathology. 2016 Oct 17 [Epub ahead of print]
Sean R Williamson, Brett Delahunt, Cristina Magi-Galluzzi, Ferran Algaba, Lars Egevad, Thomas M Ulbright, Satish K Tickoo, John R Srigley, Jonathan I Epstein, Daniel M Berney
Department of Pathology and Laboratory Medicine and Josephine Ford Cancer Institute, Henry Ford Health System, Detroit, MI, USA. ., Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago - Wellington, Wellington, New Zealand., Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic,, Cleveland, OH, USA., Section of Pathology, Fundació Puigvert, Universitat Autónoma de Barcelona, Spain., Department of Pathology, Karolinska University Hospital, Stockholm, Sweden., Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, IN, USA., Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada., Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD, USA., Department of Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.