Normal puberty and adolescent development — short case and counselling station

Station objectives

1. Stage puberty accurately using Tanner criteria, measuring testicular volume with a Prader orchidometer. [1] [2]
2. Recognise constitutional delay of growth and puberty by its pattern and counsel the young person and family. [4] [6]
3. Identify the red flags of rapidly progressive precocious puberty and construct an urgent referral plan. [3] [5]
4. Demonstrate a confidential, developmentally appropriate and consent-based examination. [8]

Candidate brief

You are the paediatric registrar in outpatient clinic. You have 10 minutes for Station A (assessment and counselling of the delayed boy) and 12 minutes for Station B (assessment and referral planning for the precocious girl). Examiners score staging accuracy, clinical reasoning, counselling language and safety. [2] [8]

Station A — Constitutional delay of growth and puberty

Setup: A 14-year-old boy and his parents. He is the smallest in his class. His father reached his adult height at 19 years. Testicular volumes are 3 mL bilaterally; height is on the 3rd centile tracking at a normal velocity; bone age reads 2 years behind chronological age. [4] [6]

Expected actions:

• Stage puberty using Tanner criteria, confirming testicular volume with the orchidometer. [2]
• Plot height, weight and height velocity on the growth chart; interpret the bone age against the clinical picture. [4]
• Name constitutional delay and give the diagnostic triad: family history, delayed bone age equal to height age, normal velocity. [6]
• Counsel that the pattern is a normal variant with a normal final adult height for the family; explain the male sequence and that he will enter it later. [6] [8]
• Address the psychosocial impact and offer monitoring every 6 to 12 months; mention the option of a short low-dose testosterone course for distress, with endocrine input. [6]
• Give a safety-net: return sooner if growth stops or falls off the centile, or if no testicular growth by 14 years persists at follow-up. [4]

Station B — Rapidly progressive precocious puberty

Setup: A 7-year-old girl with progressive breast development over 4 months, height velocity 9 cm per year, bone age advanced by 3 years, and a pubertal-range basal LH. [3] [5]

Expected actions:

• Recognise that signs before 8 years with progression, accelerated growth and a markedly advanced bone age indicate central precocious puberty, not a benign variant. [3]
• Stage puberty and perform a targeted examination including visual fields and skin (for café-au-lait spots). [5]
• State the first-line investigations: bone age (advanced), basal LH/FSH with oestradiol, and a GnRH- or agonist-stimulation test to confirm the pubertal LH response. [3]
• State the neuroimaging principle: all boys with central precocious puberty warrant brain MRI; girls under 6 years and any child with neurological signs also warrant MRI. [5]
• Construct an urgent referral to paediatric endocrinology for confirmation and consideration of GnRH-analogue suppression to protect adult height. [3] [5]
• Counsel the family honestly: this is not a normal variant and needs prompt evaluation, while avoiding unnecessary alarm. [8]

Marking anchors

Clear pass: accurate Tanner staging with orchidometry; correctly identifies constitutional delay by its triad and counsels the family with empathy; recognises rapidly progressive central precocious puberty and its red flags; states the correct investigations and the MRI principle; constructs a clear urgent referral; examines with consent and a confidential manner. [2] [3] [6] Borderline: stages puberty but misnames the variant, or recognises precocity but gives an incomplete or delayed referral plan, or counsels without addressing psychosocial impact. [8] Fail: treats pubic hair as the first sign of puberty; misses the red flags of rapidly progressive precocious puberty and offers reassurance alone; confuses lipomastia with thelarche; fails to refer a presentation outside the normal band. [3] [5] [8]

Debrief pearls

• The first sign of gonadal puberty is breast budding in girls and testicular enlargement in boys; pubic hair is adrenarche, an independent process. [1] [2]
• Constitutional delay is the most common cause of delayed puberty in boys; recognise the pattern, do not over-investigate, and do address the psychosocial cost. [6]
• Rapidly progressive central precocious puberty risks premature epiphyseal fusion and reduced adult height; it is not a watch-and-wait scenario. [5]
• All boys with central precocious puberty warrant brain MRI. [5]