Delayed Puberty, Boys

Key Features

• Indications for evaluation

  • No secondary sexual characteristics by 14 years of age

  • More than 5 years have elapsed since the first signs of puberty without completion of genital growth

• Most common cause is constitutional growth delay

• Hypogonadism in boys may be classified as

  • Primary due to absence, malfunction, or destruction of testicular tissue

  • Central due to pituitary or hypothalamic insufficiency

• Primary testicular insufficiency may be due to

  • Anorchia

  • Klinefelter syndrome (47,XXY) or other sex chromosome abnormalities

  • Enzymatic defects in testosterone synthesis

  • Inflammation or destruction of the testes following infection (mumps), autoimmune disorders, radiation, trauma, or tumor

• Central hypogonadism may accompany

  • Panhypopituitarism

  • Hypogonadotropic hypogonadism with (Kallmann syndrome) or without abnormalities in smell

  • Hyperprolactinemia

  • Isolated luteinizing hormone (LH) or follicle-stimulating hormone (FSH) deficiency

  • Destructive lesions in or near the anterior pituitary (especially craniopharyngioma and glioma)

  • Infection

  • Prader-Willi syndrome

  • Laurence-Moon syndrome (Bardet-Biedl syndrome)

• Deficiencies in gonadotropins may be partial or complete

• Functional or reversible gonadotropin may occur with chronic illness, malnutrition, hyperprolactinemia, hypothyroidism, or excessive exercise

Clinical Findings

• History should focus on whether and when puberty started, testicular descent, symptoms of chronic illness, nutritional intake, sense of smell, and family history of delayed puberty

• Physical examination should include

  • Body proportions

  • Height and weight

  • Pubertal stage

  • Testicular location, size, and consistency

• Testes < 2 cm in length are prepubertal; testes > 2.5 cm in length suggest early pubertal growth

Diagnosis

• Laboratory evaluation includes measurement of LH and FSH levels (if bone age is > 12 years)

• Elevated gonadotropins indicate primary hypogonadism or testicular failure

• Low gonadotropins on a sensitive assay are consistent with central hypogonadism and further evaluation should focus on looking for pituitary hormone deficiencies, chronic disease, undernutrition, hyperprolactinemia, or CNS abnormalities

• A radiograph of the left hand and wrist should be done to assess bone age;if bone age is delayed (< 12 years) and growth velocity is normal, constitutional growth delay is the most likely diagnosis

Treatment

• A 4- to 6-month course of low-dose depot testosterone (50–100 mg/mo) may be given to stimulate pubertal appearance and "jump-start" endogenous development in boys with simple constitutional delay

• In adolescents with permanent hypogonadism,

  • Depot testosterone is initiated with 50–100 mg intramuscularly each month and gradually increased over 3–4 years to adult dosing (200 mg every 2–4 weeks)

  • Testosterone gel, either in single-dose packets or in a pump set to dispense a preset dose, is an alternative that is applied daily