Testis & epididymis
Development
Klinefelter syndrome
Author: Turki Al-Hussain, M.D.
Topic Completed: 1 September 2012
Minor changes: 8 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Klinefelter syndrome [title] infertility
Table of Contents
Definition / general | Gross description | Microscopic (histologic) description | Electron microscopy descriptionCite this page: Al-Hussain T. Klinefelter syndrome. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisklinefelter.html. Accessed January 16th, 2021.
Definition / general
- 47XXY, reduced body and pubic hair, gynecomastia in 40 - 80%, high FSH, variable LH
- Increased risk of breast cancer and extragonadal germ cell tumor
Gross description
- Small, firm testes
Microscopic (histologic) description
- Reduced number of intratubular germ cells, some tubules are Sertoli cell only
- Also tubular sclerosis, Leydig cell nodules (appear hyperplastic due to tubular atrophy), focal spermatogenesis rarely seen
Electron microscopy description
- No annulate lamellae in Sertoli cells; microcrystal formation but no Reinke crystals in Leydig cells (Arch Pathol Lab Med 1982;106:228)
