Urology Annals (Jan 2022)

The core four - A panel of immunohistochemistry markers to diagnose and subtype testicular germ cell tumors

  • V N Ranjitha,
  • Rashmi Khemani,
  • B Vishal Rao,
  • Daphne Fonseca,
  • S Sudha Murthy,
  • Ashwin Giridhar,
  • Y Jayakarthik,
  • Rakesh Sharma,
  • K V V. N. Raju,
  • T Subramanyeshwar Rao,
  • Challa Sundaram

DOI
https://doi.org/10.4103/ua.ua_69_21
Journal volume & issue
Vol. 14, no. 1
pp. 21 – 26

Abstract

Read online

Context: Immunohistochemistry (IHC) to differentiate germ cell tumors. Aims: The aim of the study is to differentiate seminomatous and nonseminomatous germ cell tumors (GCTs) with morphological overlap using a minimal and affordable panel of IHC markers. Settings and Design: This is a retrospective observational study. Subjects and Methods: All testicular GCTs (TGCT) which were diagnosed on biopsies and/or resection specimens (prechemotherapy) between January 2014 and June 2019. The demographic, clinical, and imaging findings were noted from the medical records. Hematoxylin and eosin (H and E)-stained sections were reviewed for morphology. The IHC markers constituted Octamer-binding transcription factor (OCT) 3/4, glypican 3 (GPC3), CD117, CD30, placental-like alkaline phosphatase, Sal-like protein 4, and β-human chorionic gonadotropin (HCG). IHC markers were performed in various combinations depending on the morphology, and a panel constituting OCT 3/4, CD117, GPC3, and CD30 was performed on cases with diagnostic dilemma and morphological overlaps. Statistical Analysis Used: Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) were calculated for suggested panel of IHC OCT 3/4, CD117, GPC3, and CD30. Results: The study included 36 patients with TGCT with a mean age of 27 (15–58) years. Nonseminomatous tumors were the most common (86%). The concise panel was performed in 20/36 (56%) tumors to resolve the diagnosis. The sensitivity, specificity, PPV, and NPV for OCT3/4 were 80%, 55%, 31%, and 92% in seminomas and 65%, 100%, 100%, and 46% in embryonal carcinomas (EC), for CD117 was 89%, 82%, 73%, and 93% in seminomas and 60%, 77%, 60%, and 77% in yolk sac tumors (YST), for GPC3 was 95%, 90%, 95%, and 90% in YST, CD30 96%, 100%, 100%, and 91% in ECs, respectively. Conclusions: Designing a novel concise and affordable IHC panel constituting OCT 3/4, CD117, GPC3, and CD30 has good sensitivity and specificity in differentiating seminomas, YST, and EC, respectively. Additional markers, namely β-HCG, can be used in identifying the choriocarcinoma component.

Keywords