The World Health Organization 2016 classification of testicular germ cell tumours: a review and update from the International Society of Urological Pathology Testis Consultation Panel

Abstract

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 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, and the distinction of prepubertal tumours (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 gynaecological tract. Currently, reporting of anaplasia (seminoma or spermatocytic tumour) or immaturity (teratoma) is 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 behaviour, and should be reported.

Differentiation-Defective Human Induced Pluripotent Stem Cells Reveal Strengths and Limitations of the Teratoma Assay and In Vitro Pluripotency Assays

“…By contrast, LU07+Dox as well as the hEC tumor were principally composed of an embryonal carcinoma-like component, without any clearly differentiated tissues (Figure 2C). Accordingly, the hEC and LU07+Dox tumor were diagnosed as ”teratocarcinoma” (Damjanov and Andrews, 2007) or “embryonal carcinoma” according to the World Health Organization (WHO) guidelines (Williamson et al., 2017). …”

“…Our histological analysis of tumors revealed that the LU07+Dox tumor resembled the hEC tumor and was therefore classified as malignant teratoma or teratocarcinoma (Muller et al., 2010) or, according to the WHO nomenclature for human germ cell tumors, as a typical “embryonal carcinoma” (Williamson et al., 2017). We confirmed this diagnosis by immunohistochemistry staining for OCT3/4, NANOG, SOX2, anti-cytokeratin (AE1/AE3), and CD30 (Figure S2A and data not shown) (Ulbright et al., 2014).…”

Association Between RASSF1A Promoter Methylation and Testicular Germ Cell Tumor: A Meta-analysis and a Cohort Study

“…The new updated WHO classification system divides testicular germ cell tumors into two major groups: those that are derived from germ cell neoplasia in situ (GCNIS) and those that are not (7). Germ cell neoplasia in situ cells precedes both seminoma and non-seminoma (NSGCT) in the tumors of young adults.…”

Ovarian germ cell tumour classification: views from the testis

“…In 2016, there was a radical revision of the testicular germ cell classification to try to address some of these problems . The crucial division was between those germ cell tumours derived from germ cell neoplasia in situ (GCNIS) and those not derived from GCNIS (Figure ).…”