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pmos·pcos
Medical educationUpdated May 17, 2026

PCOS / PMOS Case Studies — 5 Patient Profiles Illustrated

PCOS / PMOS is a polymorphic syndrome: behind the same diagnosis lie radically different clinical pictures. A lean woman with no acne or hirsutism may share the same diagnosis as another with severe hyperandrogenism. These 5 fictional cases illustrate this diversity to better understand the diagnostic and therapeutic logic of each phenotype.

Understanding individual phenotypes helps you ask better questions at your appointment, interpret your results, and avoid discouragement when your journey differs from another patient's. This is also why the international ESHRE/Monash 2023 guideline emphasises individualised management rather than a single universal protocol.

These cases are entirely fictional, for educational purposes only. Names, ages, biological values and outcomes are constructed for pedagogical purposes. They do not represent any real patient and do not constitute medical advice. Consult your doctor for any therapeutic decision.
Case 1Phenotype A — Classic Complete

Marie, 26 years old

Absent cycles after stopping the pill, severe acne, hirsutism

Clinical presentation

  • Secondary amenorrhea since stopping oral contraceptives (6 months)
  • BMI 28 (mild overweight)
  • Severe cystic acne on the jaw and back since adolescence
  • Marked hirsutism: Ferriman-Gallwey score 16 (clinical threshold ≥ 6)
  • Clinical insulin resistance: intense sugar cravings, dark patches in skin folds (acanthosis nigricans)

Diagnostic workup

  • →Total testosterone: 2.8 nmol/L (normal < 1.7) — elevated
  • →AMH: 68 pmol/L (normal 15–28 by age) — very high
  • →HOMA-IR: 3.4 (insulin resistance threshold > 2.5)
  • →Pelvic ultrasound: 14 follicles per ovary, volume 13 mL — PCOM confirmed
  • →TSH, prolactin, thyroid panel: normal (differential diagnoses excluded)

Retained diagnosis

PCOS phenotype A (classic complete): all 3 Rotterdam criteria met — clinical and biochemical hyperandrogenism, anovulation, polycystic morphology.

Treatment plan

  1. 1Metformin 500 mg → titration to 1,500 mg/day (biweekly steps for GI tolerance)
  2. 2Spironolactone 100 mg/day for acne and hirsutism
  3. 3Low glycemic index diet, reduction of refined carbohydrates
  4. 4Combined aerobic + resistance exercise: 150 minutes/week
  5. 5COC (combined oral contraceptive) discussed — patient prefers to avoid in the short term

Outcome

  • ✓At 6 months: spontaneous cycle returns, HOMA-IR 2.1
  • ✓At 12 months: 3 cycles in 12 months (irregular but present), acne reduced by 70%, Ferriman score 9
  • ✓5 kg weight loss without strict caloric restriction
  • ✓Total testosterone at 1.9 nmol/L — normalised

Key takeaway

Phenotype A responds well to the combination of metformin + spironolactone + dietary changes. Patience is essential: the effect on hirsutism takes 6–12 months to become visible.

Case 2Phenotype D — Normo-androgenic

Sophie, 31 years old

Primary infertility 18 months, long cycles, no androgenic signs

Clinical presentation

  • Long cycles since puberty: 45–60 days, oligomenorrhea
  • BMI 23 (normal weight) — no excess weight
  • No clinical hyperandrogenism: no acne, no hirsutism
  • Primary infertility documented after 18 months of trying to conceive
  • Anxiety related to unfulfilled pregnancy desire

Diagnostic workup

  • →Total testosterone: 1.2 nmol/L — normal
  • →AMH: 52 pmol/L — very high
  • →LH/FSH ratio: 2.8 (elevated, suggestive of functional anovulation)
  • →Ultrasound: PCOM confirmed (22 follicles per ovary)
  • →Infectious and uterine panel for both partners: normal

Retained diagnosis

PCOS phenotype D (normo-androgenic): anovulation + polycystic morphology without hyperandrogenism. The most commonly missed phenotype as no skin symptoms are present.

Treatment plan

  1. 1Letrozole 2.5 mg days 3–7 for ovulation induction (off-label, ESHRE 2023 first-line recommendation)
  2. 2Follicular ultrasound monitoring at days 10–12
  3. 3Ovulation trigger if follicle ≥ 18 mm (hCG injection or timed intercourse)
  4. 4Myo-inositol 4 g/day in parallel to improve oocyte quality
  5. 5Psychological support: anxiety management related to fertility treatment

Outcome

  • ✓Cycle 1: triggered ovulation, no pregnancy
  • ✓Cycle 2: ovulation, biochemical pregnancy — early miscarriage
  • ✓Cycle 3: ongoing pregnancy confirmed at 7 weeks
  • ✓Reinforced first-trimester monitoring — delivery at term

Key takeaway

Phenotype D is under-diagnosed: with no acne or hirsutism, PCOS is often not considered. Very elevated AMH and polycystic morphology are the diagnostic keys. Letrozole remains the first-line ovulation inducer.

Case 3PCOS/PMOS with Early Metabolic Syndrome

Amina, 22 years old

Irregular cycles since menarche, BMI 31, insulin resistance

Clinical presentation

  • Menarche at age 14 — irregular cycles from the start (28–90 days)
  • BMI 31 (grade I obesity)
  • Documented insulin resistance: HOMA-IR 3.8 (normal < 2.5)
  • Acanthosis nigricans at the neck and armpits
  • No significant acne, mild body hair (Ferriman 5 — below clinical threshold)
  • Family history: mother diagnosed with type 2 diabetes at age 41

Diagnostic workup

  • →Total testosterone: 1.5 nmol/L — upper normal limit
  • →AMH: 38 pmol/L — elevated
  • →Fasting blood glucose: 1.02 g/L (pre-diabetes)
  • →HbA1c: 5.7% (pre-diabetes range)
  • →Lipid panel: triglycerides 1.8 mmol/L (mildly elevated), HDL 0.9 mmol/L (low)
  • →Ultrasound: 18 follicles per ovary, volume 11.5 mL

Retained diagnosis

PCOS/PMOS with early metabolic syndrome. Phenotype classification is nuanced (sub-clinical Ferriman, borderline testosterone) — priority is given to the metabolic aspect in this young patient.

Treatment plan

  1. 1Metformin 500 mg → titration to 1,000 mg/day (adjusted for GI tolerability)
  2. 2Myo-inositol 4 g/day (40:1 ratio with D-chiro-inositol) in parallel
  3. 3Physical activity programme: 150 min/week aerobic + 2 resistance sessions
  4. 4Dietitian consultation: Mediterranean diet, reduction of fast sugars
  5. 5Quarterly metabolic monitoring: blood glucose, HbA1c, lipids

Outcome

  • ✓At 6 months: HOMA-IR 2.1 (normalised), 6 kg weight loss
  • ✓At 6 months: cycles every 35–45 days (improved regularity)
  • ✓At 12 months: HbA1c 5.4% (normalised), triglycerides within normal range
  • ✓Sustained motivation driven by visible biological improvements

Key takeaway

In young adults with high BMI and insulin resistance, early intervention is critical for preventing type 2 diabetes. The combination of metformin + inositol + physical activity is effective and well tolerated.

Case 4Known PCOS + Early Perimenopause

Claire, 38 years old

Phenotype A PCOS diagnosed 10 years ago — cycles paradoxically regularising

Clinical presentation

  • Phenotype A PCOS diagnosed at age 28 — well managed on spironolactone
  • Cycles paradoxically regularising (perimenopause effect in PCOS)
  • Mild nocturnal hot flashes for the past 3 months
  • Mild vaginal dryness, sleep disturbances
  • Stable BMI at 25, no recent weight gain

Diagnostic workup

  • →AMH: 2.1 pmol/L — marked decline (falling ovarian reserve)
  • →FSH: 12 IU/L (beginning of perimenopausal rise, normal < 10 in follicular phase)
  • →LH: 8 IU/L
  • →Total testosterone: still mildly elevated at 1.6 nmol/L
  • →Metabolic panel stable: normal blood glucose, lipids within range

Retained diagnosis

Phenotype A PCOS in perimenopausal transition. Falling AMH and rising FSH signal the onset of ovarian decline. The apparent regularisation of cycles may mask persistent anovulation.

Treatment plan

  1. 1Gradual tapering of spironolactone (hyperandrogenism naturally decreases in perimenopause)
  2. 2Continued annual enhanced metabolic monitoring (cumulative cardiovascular risk from PCOS)
  3. 3Discussion of HRT (hormone replacement therapy) if symptoms worsen
  4. 4Maintain metformin if HOMA-IR remains elevated
  5. 5Baseline bone density scan planned (risk of osteoporosis if early menopause)

Outcome

  • ✓Spironolactone reduced to 50 mg/day — good tolerance
  • ✓Hot flashes managed without HRT initially (phytoestrogens, sleep hygiene)
  • ✓Biannual gynaecological follow-up established
  • ✓HRT considered if symptoms worsen over the next 6–12 months

Key takeaway

PCOS evolves at menopause: hyperandrogenism decreases, cycles may paradoxically regularise. Cumulative metabolic risk (cardiovascular, type 2 diabetes) persists and justifies ongoing medical monitoring beyond age 40.

Case 5Phenotype C — Ovulatory (frequently under-diagnosed)

Laura, 29 years old

Regular cycles, persistent acne and hirsutism, highly athletic

Clinical presentation

  • Regular cycles of 28–32 days — patient is not concerned about her cycles
  • Persistent cystic acne on the jaw line for 5 years, unresponsive to topical treatments
  • Hirsutism: Ferriman-Gallwey score 11 (chin, upper lip, abdomen)
  • Intense athletic activity: 10 hours/week (trail running + strength training)
  • BMI 21 (lean) — no excess weight
  • Presents for acne and hirsutism — not for cycles

Diagnostic workup

  • →Total testosterone: 2.1 nmol/L — elevated
  • →SHBG: 32 nmol/L — low (increases the active free fraction)
  • →Calculated free testosterone: elevated
  • →AMH: 41 pmol/L — elevated
  • →Ultrasound: 19 follicles per ovary — PCOM
  • →LH/FSH: 1.8 (normal as ovulation is present)

Retained diagnosis

PCOS phenotype C (ovulatory): biochemical and clinical hyperandrogenism + polycystic morphology, with regular cycles. This phenotype is under-diagnosed because regular cycles falsely reassure clinicians. Intense physical activity can mask mild dysovulation.

Treatment plan

  1. 1Spironolactone 75 mg/day (dose adapted to intense physical activity — potassium monitoring)
  2. 2Mechanical contraception or condoms during spironolactone treatment (potential teratogen)
  3. 3COC with anti-androgenic effect discussed but declined by patient (avoids hormones)
  4. 4Azelaic acid 20% topical + gentle pH 5.5 cleanser
  5. 5Supplements: zinc bisglycinate 30 mg, N-acetylcysteine 600 mg

Outcome

  • ✓At 3 months: acne reduced by 40% — first significant improvement
  • ✓At 6 months: Ferriman score 7 (notable improvement), acne nearly resolved
  • ✓At 12 months: Ferriman 6, acne in remission
  • ✓Potassium level monitored: stable (compensated by athletic potassium intake)

Key takeaway

Regular cycles do not exclude PCOS. Phenotype C is often missed because the patient consults for acne or hirsutism — not for her cycles. Spironolactone alone may be sufficient when fertility is preserved.

Frequently Asked Questions

Are the clinical cases presented here real patients?
No. All cases are fictional, constructed from real epidemiological data (phenotype prevalence, typical biological values, treatment responses). They are published for educational purposes only and do not correspond to any real patient.
Why do the 4 Rotterdam phenotypes present so differently?
Because PCOS/PMOS is a heterogeneous spectrum. Only 2 of the 3 Rotterdam criteria are required for diagnosis — creating 4 possible combinations with very different clinical presentations. This is why the authors of the 2023 guideline (Teede et al., Nature Medicine) emphasise individualised management rather than a one-size-fits-all protocol.
Can PCOS be diagnosed in a lean woman?
Yes, absolutely. Approximately 20–30% of women with PCOS have a normal BMI (lean PCOS). Sophie's case (phenotype D, BMI 23) and Laura's case (phenotype C, BMI 21) illustrate this. The absence of excess weight should not rule out the diagnosis when the biochemical and ultrasound criteria are present.
Does PCOS disappear at menopause?
Not completely. As Claire's case (age 38) illustrates, PCOS evolves: hyperandrogenism tends to decrease naturally, and cycles may paradoxically regularise in perimenopause. However, cumulative metabolic risk (cardiovascular, type 2 diabetes) persists and justifies ongoing medical follow-up.
Can intense exercise mask PCOS?
Yes, partially. Laura's case (10 hours of sport per week, regular cycles) illustrates how intense physical activity can improve ovulation and cycle regularity, thereby masking underlying dysovulation. This can delay diagnosis if the clinician does not test for biochemical hyperandrogenism.

See also

PCOS / PMOS Phenotype Quiz →PCOS treatment options →Metformin and PCOS →Spironolactone and PCOS →GLP-1 agonists and PCOS →Letrozole and PCOS →
Information, not a diagnosis. This page offers general educational content. It does not constitute a diagnosis and does not replace a personalised medical consultation. These fictional case studies are for illustrative purposes only.

How was this page written? See our editorial methodology →

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