H&E and OCT4/CD34 for the assessment of lympho-vascular invasion in seminoma and embryonal carcinoma

Background: Lymphovascular invasion (LVI) is a relevant prognostic factor in germ cell tumors of the testis (GCTT), and it is included in the pT stage. However, its detection on hematoxylin and eosin (H&E) slides is very challenging, and previous studies reported fair to moderate inter-observer agreement among dedicated uropa-thologists. In the present study, we tested H&E and a recently developed in-house double staining for OCT4/ CD34 to detect LVI in GCTT. Methods: Nine authors [5 non-uropathologists and 4 uropathologists] independently evaluated 34 consecutive and retrospectively enrolled cases of GCTT. We assessed the inter-observer agreement (Fleiss's Kappa) with both H&E and OCT4/CD34. Besides, we compared the consensus diagnosis on both H&E and OCT4/CD34-stained sections with the original diagnosis to evaluate the pT re-staging (McNemar test) and identify the sources of disagreement.

Automated summary

In this study, H&E and OCT4/CD34 staining were tested for detecting lymphovascular invasion (LVI) in germ cell tumors of the testis (GCTT). The inter-observer agreement for both H&E and OCT4/CD34 was assessed, and the consensus diagnosis on both stains was compared with the original diagnosis to evaluate pT restaging and identify sources of disagreement.