A 17-year-old girl is seen for primary amenorrhea. There is no development of breasts or hair in the pubic or axillary region. Her height is 155 cm, and her weight is 48 kg. She has bilateral inguinal masses. The uterus, fallopian tube, and Ovary are absent on ultrasound examination. What is the most likely diagnosis?

Correct Answer: B. Hypergonadotropic hypogonadism

This case presents primary amenorrhea with absent secondary sexual characteristics, absent uterus/fallopian tubes/ovaries, and bilateral inguinal masses in a 17-year-old girl—the classic presentation of 46,XY gonadal dysgenesis (Swyer syndrome), a form of hypergonadotropic hypogonadism. The bilateral inguinal masses are streak gonads (dysgenetic gonadal tissue), which produce neither estrogen nor anti-Müllerian hormone (AMH). Without AMH, the Müllerian ducts (uterus, fallopian tubes, ovaries) fail to regress but also fail to develop normally, resulting in their absence. The absent estrogen production triggers high FSH and LH (hypergonadotropic state), causing primary amenorrhea and absent breast/pubic hair development. The normal height (155 cm) and BMI (20 kg/m²) distinguish this from Turner syndrome, which presents with short stature (typically <150 cm) and characteristic skeletal features. Hypergonadotropic hypogonadism encompasses all conditions of primary gonadal failure (ovarian dysgenesis, gonadal agenesis, premature ovarian failure), and this patient fits the diagnostic criteria: elevated gonadotropins, absent secondary sexual development, and primary amenorrhea due to gonadal failure rather than CNS or structural uterine pathology.

Why the other options are wrong

A. Turner syndrome — Turner syndrome (45,X or mosaicism) classically presents with short stature (typically <150 cm), webbed neck, shield chest, and cardiac/renal anomalies. This patient's height of 155 cm is normal for an Indian female adolescent. Additionally, Turner syndrome presents with streak gonads but uterus and fallopian tubes are present (unlike this case). The bilateral inguinal masses and complete absence of Müllerian structures point to 46,XY gonadal dysgenesis, not Turner syndrome. C. Polycystic ovary syndrome — PCOS presents with hyperandrogenism (hirsutism, acne, male-pattern baldness), irregular menses (not primary amenorrhea), and polycystic ovaries on ultrasound. This patient has absent secondary sexual characteristics (no pubic/axillary hair, no breast development), indicating hypogonadism, not hyperandrogenism. PCOS also requires presence of ovaries; this patient has absent ovaries. PCOS is a diagnosis of exclusion and does not explain the absent Müllerian structures or inguinal masses. D. Complete androgen insensitivity syndrome — CAIS (46,XY) presents with absent pubic/axillary hair and primary amenorrhea, but patients typically have normal breast development (due to peripheral aromatization of testosterone to estrogen) and a blind-ending vagina with absent uterus. This patient has absent breast development, ruling out CAIS. Additionally, CAIS presents with testes in the inguinal canal (not streak gonads), and the gonadotropins are typically normal or low-normal, not elevated. The hypergonadotropic state here indicates gonadal dysgenesis, not androgen insensitivity.

High-Yield Facts

Mnemonics

SWYER = 46,XY Gonadal Dysgenesis Streak gonads (bilateral inguinal masses) + Womb absent (no uterus/tubes/ovaries) + Yet normal height + Estrogen deficient (no breast development) + Raised gonadotropins (FSH/LH high). Use when you see primary amenorrhea + absent Müllerian structures + normal stature + inguinal masses in a 46,XY individual. HyperGONADotropic = GONADs Fail When gonadotropins (FSH/LH) are high, the gonads have failed to respond—primary gonadal failure. Opposite of hypogonadotropic hypogonadism (low FSH/LH = pituitary/hypothalamic failure). Use to quickly distinguish primary from secondary hypogonadism.

NBE Trap

NBE may pair "bilateral inguinal masses" with CAIS (testes in inguinal canal) to distract from the key discriminator: absent breast development (CAIS has normal breasts due to aromatization, whereas gonadal dysgenesis has absent breasts due to no estrogen production). Students who focus only on the inguinal masses without assessing secondary sexual characteristics may incorrectly choose CAIS.

Clinical Pearl

In Indian clinical practice, any 46,XY gonadal dysgenesis patient with inguinal streak gonads requires gonadectomy due to 30–50% risk of malignancy (gonadal tumors, dysgerminoma). Hormone replacement therapy (estrogen + progesterone) is then initiated to induce secondary sexual development and maintain bone health—a critical counseling point for adolescent girls presenting with primary amenorrhea and inguinal masses.

_Reference: DC Dutta's Textbook of Gynaecology (6th ed.), Ch. 8 (Amenorrhea); Harrison's Principles of Internal Medicine, Ch. 405 (Disorders of Sex Development)_