STEPTRACKERREPRODUCTIVE | PATHOLOGY + ENDOCRINE + ANATOMY | HIGH-YIELD REVIEW

Ovary — Non-Neoplastic

Functional cysts, polycystic ovary syndrome, torsion, and ovaries that fail early or are pushed too hard.

FOCUS ON
Follicular cysts are the most common ovarian mass in young women (failed ovulation). PCOS: ↑ LH:FSH, insulin resistance, androgen excess, anovulation, many peripheral follicles → hirsutism, infertility, ↑ endometrial cancer risk. Torsion: sudden one-sided pain, enlarged ovary with ↓ Doppler flow — surgery. Theca lutein cysts = very high hCG.
DISORDER
MECHANISM
FEATURES
CLUE · TREATMENT
Follicular cyst
most common ovarian mass
Dominant follicle fails to rupture and keeps growing
Thin-walled, unilocular, usually < 8 cm; may make estrogen
Resolves in 1–2 cycles
Corpus luteum cyst
Corpus luteum fills with fluid or blood
Luteal phase or early pregnancy; may hemorrhage → acute pain, hemoperitoneum
Makes progesterone
Theca lutein cysts
Excess hCG overstimulates theca cells
Bilateral, multiple cysts
Molar pregnancy, choriocarcinoma, twins, fertility drugs
Polycystic ovary syndrome
↑ LH:FSH + insulin resistance → theca cells make excess androgen; ↓ SHBG; follicles arrest
Oligo/amenorrhea, hirsutism, acne, obesity, infertility, acanthosis nigricans; enlarged ovaries with many peripheral follicles
Most common cause of anovulatory infertility
PCOS — risks & treatment
Unopposed estrogen + metabolic syndrome
↑ endometrial hyperplasia/carcinoma, type 2 DM, dyslipidemia, sleep apnea
Weight loss, combined OCPs, letrozole or clomiphene for ovulation, metformin, spironolactone
Ovarian torsion
Enlarged ovary (cyst, dermoid) twists on the infundibulopelvic and ovarian ligaments → venous then arterial obstruction
Sudden severe unilateral pelvic pain, nausea, vomiting; adnexal mass
Doppler: ↓ flow, "whirlpool" · urgent detorsion
Ovarian hyperstimulation syndrome
hCG trigger in fertility treatment → VEGF → capillary leak
Enlarged ovaries, ascites, hemoconcentration, oliguria, thrombosis
After ovulation induction
Primary ovarian insufficiency
Follicle depletion before 40: Turner, fragile X premutation, autoimmune, chemo/radiation
Amenorrhea, hot flashes, infertility; ↑ FSH, ↓ estrogen
Hormone replacement to protect bone and heart
Stromal hyperthecosis
Luteinized theca cells in ovarian stroma
Postmenopausal women; marked virilization, bilateral solid enlargement
More severe than PCOS
Ruptured / hemorrhagic cyst
Cyst wall bleeds or ruptures
Sudden pain after intercourse or exercise; free fluid; mimics ectopic
Check hCG first

Mechanism — PCOS

Insulin resistanceHyperinsulinemia
→
↑ LH pulses↑ LH:FSH
→
Theca cells↑ Androgens · ↓ SHBG
→
Follicles arrestAnovulation
→
Unopposed estrogenEndometrial risk

Excess androgen is converted in fat to estrone — estrogen is present but there is no ovulation, so no progesterone.

Hormone patterns in amenorrhea

STATE
FSH
LH
ESTROGEN
PCOS
Normal / ↓
↑ (LH:FSH > 2)
Normal (+ ↑ androgen)
Ovarian insufficiency / menopause
↑↑
↑
↓
Hypothalamic amenorrhea
↓
↓
↓
Prolactinoma
↓
↓
↓ (+ ↑ prolactin)
Ligaments to know
Suspensory (infundibulopelvic) ligament carries the ovarian vessels — the ureter runs close by when it is ligated · ovarian ligament joins ovary to uterus · cardinal ligament carries uterine vessels over the ureter.

How it's tested

COMMON CONFUSIONA follicular cyst is a mid-cycle event; a corpus luteum cyst occurs after ovulation or in early pregnancy and is the one that bleeds.
THE TRAPNormal ovarian blood flow on Doppler doesn't fully rule out torsion (dual blood supply, intermittent twisting). Strong suspicion → surgery.
YOUR APPROACHAcute pain vs chronic cycle problem → hCG → ultrasound (simple cyst, many follicles, enlarged twisted ovary) → hormones (LH:FSH, FSH, androgens).

If you see… think…

Young woman with incidental simple 4 cm ovarian cyst → follicular cyst
Early pregnancy, sudden pain, hemoperitoneum from the ovary → ruptured corpus luteum cyst
Bilateral ovarian cysts + very high β-hCG → theca lutein cysts (mole)
Obese woman with hirsutism, irregular periods, acanthosis nigricans → PCOS
Ovulation induction drug of choice in PCOS → letrozole
Long-term PCOS with abnormal bleeding → endometrial hyperplasia/carcinoma
Sudden severe one-sided pelvic pain, vomiting, enlarged ovary → torsion — detorsion
IVF patient with ascites and hemoconcentration → ovarian hyperstimulation syndrome
Amenorrhea at 34 with ↑ FSH and ↓ estrogen → primary ovarian insufficiency
Short stature, streak ovaries, amenorrhea → Turner syndrome