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OG23.1 | Normal and Abnormal Puberty — SDL Guide (Part 3)

Self-Assessment

The questions below are designed to test your active recall and application of the key concepts covered in this module. Rather than simply re-reading the text, attempt each question from memory first — this retrieval practice is one of the most evidence-based strategies for consolidating clinical knowledge. For each question, consider not just the answer but the clinical reasoning chain that connects the physiology to the management decision. If a question exposes a gap, return to the relevant section and then attempt an answer in your own words before reviewing the model answer.

These questions are pitched at the level of a final-year MBBS viva voce or written short answer — the same level at which this competency (OG23.1) will be assessed. Pay particular attention to the ability to classify causes systematically and to outline a structured investigation approach, as these are the skills most commonly tested at this level.

Diagnostic flowchart for abnormal puberty in girls: left amber branch covers precocious puberty with LH/FSH gonadotropin decision splitting into central (MRI brain) versus peripheral (pelvic US, adrenal imaging) pathways; right blue branch covers delayed puberty with FSH decision splitting into hypergonadotropic (karyotype), hypogonadotropic (MRI, GnRH test), and outflow obstruction (pelvic US, hymen inspection) categories. — **Panel A:** Full diagnostic flowchart — root: 'Abnormal Puberty'; left branch (amber): precocious puberty → LH/FSH diamond → high (central: MRI brain, bone age) / low (peripheral: pelvic US, adrenal imaging, β-hCG, TFTs); right branch (teal): delayed puberty → FSH diamond → high (hypergonadotropic: karyotype) / low (hypogonadotropic: MRI, GnRH stim test, anosmia screen) / normal FSH + anatomy (outflow obstruction: pelvic US, hymen inspection).

Draw or describe the HPO axis as it operates during puberty: identify the hypothalamic pulse generator, the pituitary hormones released, the ovarian response, and the feedback loops.
Tanner staging: For a girl at Tanner B4/PH3, describe the expected breast and pubic hair findings and state whether menarche has likely occurred yet.
Classify delayed puberty in a 15-year-old with no menarche but normal breast development (B4): what anatomical category of primary amenorrhoea does she fall in? What initial investigation would you order first?
Differentiate: A 7-year-old girl with isolated breast budding (B2) and a 7-year-old with B2 + PH2 + bone age 10 yr + accelerated growth. How do your management approaches differ?

SELF-CHECK

A 15-year-old girl has normal breast and pubic hair development (Tanner B4/PH4) but has never had a period. She has cyclical lower abdominal pain monthly. Pelvic ultrasound shows a midline cystic mass (haematocolpos). The most likely diagnosis and management is:

A. Turner syndrome — karyotype and oestrogen replacement

B. MRKH syndrome — surgical creation of neovagina

C. Imperforate hymen — hymenectomy to drain haematocolpos

D. Kallmann syndrome — GnRH pump therapy

Reveal Answer

Answer: C. Imperforate hymen — hymenectomy to drain haematocolpos

Normal secondary sex characteristics (normal oestrogen) + cyclical pain + haematocolpos = outflow tract obstruction. Imperforate hymen is the most common cause, presenting with a bluish bulging hymen at the introitus and haematocolpos on ultrasound. Treatment is surgical hymenectomy. This is eugonadism with outflow obstruction — FSH/LH are normal, which distinguishes it from Turner syndrome or Kallmann syndrome.

Interactive practice: Multiple Choice

Interactive practice: True / False