A 16-year-old girl has primary amenorrhoea with normal breast development (Tanner stage IV), no pubic or axillary hair, absent uterus on ultrasound, and bilateral inguinal swellings. Karyotype is 46,XY. The most likely diagnosis is:

• A Turner syndrome (45,X)
• B Complete androgen insensitivity syndrome (CAIS) ✓
• C Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome
• D Swyer syndrome (46,XY pure gonadal dysgenesis)

Explanation

CAIS presents with 46,XY karyotype, female phenotype with normal breast development (from peripheral oestrogen converted from testosterone), absent uterus, absent/sparse pubic and axillary hair, and bilateral undescended testes in the inguinal canal. MRKH has 46,XX with absent uterus. Swyer syndrome has streak gonads and absent secondary sexual development. Turner syndrome is 45,X with short stature and somatic stigmata.

Reference: Shaw's Textbook of Gynaecology, 17th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.