Cite this page: Al-Hussain T. Gonadotropin deficiency. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisgonadotropin.html. Accessed January 20th, 2021.
Definition / general
- For normal function, require intact axis of GnRH to FSH / LH
- Prepubertal:
- Delayed puberty: failure of adolescent development by age 16
- Deficiency if gonadotropins were never secreted normally
- Most patients with associated syndromes have major congenital anomalies
- Kallmann syndrome: young adults / teenagers with prepubertal testes, anosmia / hyposmia (loss / reduction in sense of smell), cleft lip / palate, color blindness, short fourth metacarpals, low LH, FSH and testesterone
- LH mutation preventing binding to receptor: high LH, normal FSH, low testosterone, no Leydig cells, maturation arrest
- Postpubertal:
- Selective LH deficiency: normal FSH, active spermatogenesis with normal tubules, low LH and testosterone, low semen volume, reduced / absent Leydig cells
- Selective FSH deficiency: normal LH, normal testosterone, variable sperm counts, low FSH, infertile with hypospermatogenesis, spermatogenesis with germ cell aplasia and incomplete maturation arrest
Etiology
- Postpubertal:
- Pituitary or hypothalamic trauma, surgery, tumor, radiation, androgens / estrogens
Treatment
- Prepubertal:
- Exogenous FSH and LH produce normal appearing and functioning testes
- Postpubertal:
- FSH and LH produce normal appearing and functioning testes
Microscopic (histologic) description
- Prepubertal
- Testis resembles that in prepubertal child - small tubules without lumina, prepubertal Sertoli cells, scattered spermatogonia
- No recognizable Leydig cells
- Postpubertal:
- Histology progresses from incomplete to complete maturation arrest, germ cell hypoplasia, germ cell aplasia, sclerotic tubules; tubules have thick / fibrotic walls, may have loss of Leydig cells
- High dose estrogens for sex change patients cause immature Sertoli cells, germ cell hypoplasia and Leydig cell atrophy
- Low dose estrogens for prostate adenocarcinoma cause maturation arrest and partial Leydig cell atrophy