📋 MOCK OSCE · FCPS, MCPS, MD PAEDIATRICS ⏱ 10 min · PRECOCIOUS PUBERTY

Precocious Puberty · Short Case

Candidate task: perform focused examination on a child with precocious puberty, discuss differential diagnosis, investigations, management & follow‑up.
Pre‑exam Protocol
⏤ · Wash, Warm, Introduce, Position, Expose, Approach ▾

Standard pre‑examination protocol – must be demonstrated:

🖐 Wash hands with sterilizing solution.
🔥 Warm hands and stethoscope.
👋 Introduce yourself to child & parent.
🧍 Position child: standing for inspection, then sitting, then lying (as needed).
👕 Exposure — chest and limbs fully exposed, warm environment.
➡️ Approach from the right side.
✔ CPSP marker: Pre‑exam Protocol is observed and scored.
1. Clinical Examination (≈6 min)
02 General Look (Inspection from end of bed) ▾

Key observations:

  • Body habitus: tall for age (early growth spurt), masculine/feminine proportions.
  • Dysmorphic features: neurofibromatosis (café‑au‑lait spots), McCune‑Albright (coast of Maine spots, fibrous dysplasia).
  • Nutritional status: obesity (exogenous, hypothyroidism).
  • Tanner staging: breast development (girls), testicular enlargement (boys) – stage and symmetry.
  • Skin: acne, greasy skin (androgen effect), pigmentation (CAH, McCune‑Albright).
  • Activity & intellect: behaviour (early puberty can affect mood).
👁 Red flags: isolated breast development (thelarche) vs full puberty. Preocious puberty in boys is more likely to be pathological.
03 Measurements & Growth Parameters ▾

Anthropometry:

  • Height: plot on growth chart – advanced height for age (early growth). Bone age is the key investigation (advanced > 2 SD).
  • Height velocity: accelerated (true precocious puberty).
  • Upper segment / Lower segment (US:LS) ratio: may be low (if growth spurt has occurred).
  • Head circumference: may be large (intracranial pathology).
  • Weight: BMI; overweight (Cushing, hypothyroidism).
📏 Key: advanced bone age + accelerated height velocity → true precocious puberty. Bone age > chronological age by >2 years is a red flag.
04 General Physical Exam (Hands → Face → Chest → Limbs) ▾

Systematic examination:

  • Hands: fine tremor (hyperthyroidism), café‑au‑lait spots (NF‑1, McCune‑Albright).
  • Face: acne (androgen excess), moon face (Cushing), coarse features (hypothyroidism – Van Wyk‑Grumbach).
  • Eyes: visual fields (bitemporal hemianopia – pituitary/hypothalamic tumour), Lisch nodules (NF‑1), exophthalmos (hyperthyroidism).
  • Neck: goitre (hypothyroidism, Graves’).
  • Chest: breast development (girls – Tanner stage), gynecomastia (boys – Klinefelter, testicular tumour).
  • Cardiovascular: tachycardia (hyperthyroidism), hypertension (CAH, Cushing).
  • Abdomen: organomegaly (hepatoblastoma – hCG secreting), adrenal mass, ovarian mass.
  • Genitalia (boys): testicular volume (orchidometer), penile length, symmetry (asymmetrical → tumour).
  • Genitalia (girls): clitoromegaly (CAH, androgen‑secreting tumour), vaginal discharge (oestrogen effect).
  • Gait & back: scoliosis (McCune‑Albright), neurological signs (intracranial tumour).
🔍 Key associations: café‑au‑lait + polyostotic fibrous dysplasia + precocious puberty → McCune‑Albright. Hypothyroidism + precocious puberty (Van Wyk‑Grumbach) – rare.
05 Developmental Assessment & Associated Signs ▾

Assess:

  • Motor milestones: may be advanced (early growth).
  • Language: may be advanced (early development).
  • Intellectual disability: if underlying syndrome (NF‑1, McCune‑Albright).
  • Behaviour: mood swings, aggression (hormonal effects), psychosocial issues (early puberty can cause bullying).
  • Neurological: visual field defects, headaches (hypothalamic hamartoma, optic glioma).
  • Associated signs: café‑au‑lait spots (NF‑1), bony deformities (McCune‑Albright).
🧠 Genetic clues: precocious puberty + café‑au‑lait + optic glioma → NF‑1. Precocious puberty + polyostotic fibrous dysplasia + café‑au‑lait (coast of Maine) → McCune‑Albright.

📋 Case Presentation – (fill in during exam)

This is a _____-year-old _____ child, referred for _____ (early breast development / testicular enlargement / pubic hair / growth spurt). On examination, the child appears _____ (well/unwell/lethargic), with _____ (body habitus / dysmorphic features). Measurements: height _____ percentile, bone age _____ (advanced/delayed), weight _____ percentile. Tanner staging: breasts _____, pubic hair _____, testes (boys) _____ mL. General exam: _____ (skin, eyes, neck, abdomen, genitalia). Developmental: _____ (advanced/appropriate/delayed). Associated signs: _____.

2. Viva Discussion (≈4 min)
06 Viva · Differential, Investigations, Management, Follow‑up ▾
🔹 Differential Diagnosis

Central (GnRH‑dependent) Precocious Puberty
• Idiopathic (most common in girls)
• CNS tumours (hypothalamic hamartoma, optic glioma, craniopharyngioma)
• CNS irradiation, trauma, infection
• Neurofibromatosis type 1 (optic glioma)
Peripheral (GnRH‑independent) Precocious Puberty
• McCune‑Albright syndrome
• Congenital adrenal hyperplasia (21‑hydroxylase, 11β‑hydroxylase)
• Gonadal tumours (ovarian – granulosa cell; testicular – Leydig cell)
• hCG‑secreting tumours (hepatoblastoma, germinoma)
• Exogenous sex steroids (ingestion, creams)
• Primary hypothyroidism (Van Wyk‑Grumbach – rare)
Variants (not true precocious puberty)
• Premature thelarche (isolated breast development)
• Premature adrenarche (isolated pubic hair)
• Premature menarche

🔹 Investigations – Diagnosis

• Bone age – advanced (true precocious puberty).
• GnRH stimulation test – pubertal LH response (central) vs prepubertal (peripheral).
• Basal LH, FSH, oestradiol (girls), testosterone (boys) – elevated in central puberty.
• 17‑OHP, androstenedione, DHEAS – elevated in CAH.
• hCG – elevated in hCG‑secreting tumours.
• Thyroid function – to exclude hypothyroidism.

🔹 Investigations – Aetiology

• MRI brain – to identify CNS lesions (hamartoma, tumour).
• Pelvic ultrasound – ovarian cysts/tumours (girls).
• Testicular ultrasound – Leydig cell tumours (boys).
• Abdominal ultrasound – hepatoblastoma, adrenal mass.
• Skeletal survey – fibrous dysplasia (McCune‑Albright).
• Genetic – FISH (NF‑1), GNAS (McCune‑Albright), CYP21A2 (CAH).

🔹 Investigations – Exclude Others

• GnRH stimulation test – differentiate central vs peripheral.
• 17‑OHP – exclude CAH.
• Thyroid function – exclude hypothyroidism.
• hCG – exclude hCG‑secreting tumours.
• Imaging – to exclude tumours (CNS, gonadal, adrenal).

🔹 Investigations – Rule Out Complications

• Ophthalmology – visual fields (if CNS lesion).
• Neurology – if CNS lesion.
• Cardiac – if McCune‑Albright (cardiac involvement rare).
• Psychosocial – assess impact on child & family.

🔹 Management – Across Organ Systems

Central (GnRH‑dependent)

GnRH analogues (leuprolide, triptorelin) – arrest puberty, preserve adult height.

Peripheral – McCune‑Albright

Aromatase inhibitors (letrozole, anastrozole); tamoxifen.

Peripheral – CAH

Glucocorticoid (hydrocortisone) + mineralocorticoid (fludrocortisone) replacement.

Peripheral – Tumour

Surgical excision (gonadal, adrenal, hepatoblastoma).

Peripheral – Hypothyroidism

Thyroxine replacement.

Peripheral – Exogenous

Remove source of sex steroids.

Psychosocial

Counselling, support for child and family (early puberty can cause bullying, emotional issues).

Surveillance

Monitor growth, bone age, hormone levels; regular imaging if tumour.

📈 Prognosis

  • Idiopathic central: good if treated early; near‑normal adult height.
  • CNS lesion: depends on lesion; GnRH analogues improve height.
  • McCune‑Albright: variable; treatment with aromatase inhibitors can improve height.
  • CAH: good with adequate replacement; growth may be affected by overtreatment.
  • Tumour: depends on tumour type and resectability.
  • Premature thelarche/adrenarche: excellent; no treatment needed.

📋 Follow‑up Schedule

  • Central on GnRH analogues: endocrinology 3‑6 monthly; bone age annually.
  • McCune‑Albright: endocrinology 3‑6 monthly; monitor for other endocrinopathies.
  • CAH: endocrinology 3‑4 monthly; growth, blood pressure, electrolytes.
  • Tumour: oncology/endocrinology; regular imaging.
  • Premature variants: reassure; monitor for progression.
  • Transition: to adult endocrinology for ongoing care.
💡 Examiner expectation: differentiate central vs peripheral precocious puberty using history, examination, and GnRH stimulation test. Know the key causes and management strategies. Be aware of the psychosocial impact of early puberty.
📚 Visit paeds.online for more CPSP resources
Mock OSCE · Precocious Puberty · Based on Wyne‑Harris, Nelson & Pediatric Clinical Advisor