Endometrial sampling and endometriosis

Indications for Endometrial Histological Sampling

Under Australian clinical practice guidelines, histological evaluation of the endometrium is mandatory in the following clinical scenarios to rule out atypical hyperplasia and endometrial carcinoma:

• All women aged $\ge 45\text{ years}$ presenting with abnormal uterine bleeding.
• Women aged $< 45\text{ years}$ with persistent abnormal uterine bleeding or significant risk factors for endometrial neoplasia:
  • Body mass index (BMI) $\ge 30\text{ kg/m}^2$ (peripheral aromatization of androgens to oestrogens in adipose tissue).
  • Chronic anovulation (e.g., polycystic ovary syndrome).
  • Nulliparity or late menopause.
  • Unopposed oestrogen therapy or tamoxifen use.
  • Hereditary cancer syndromes (e.g., Lynch syndrome / HNPCC).
  • Failure of medical therapy or persistent intermenstrual bleeding.
• Outpatient Pipelle suction endometrial aspiration biopsy is the first-line technique (sensitivity $> 90\%$ for diffuse endometrial pathology). If Pipelle sampling is non-diagnostic, technically unfeasible (e.g., severe cervical stenosis), or if bleeding persists despite a benign biopsy, formal hysteroscopy with targeted dilatation and curettage (D&C) is required.

Endometriosis: Pathophysiology, Presentation & Management

Endometriosis is an oestrogen-dependent, chronic inflammatory condition characterized by the presence of functional endometrial glands and stroma in anatomical sites outside the uterine cavity. In Australia, it affects approximately 1 in 9 women of reproductive age.

Clinical Presentation and Physical Examination

• Symptom Complex: The cardinal triad consists of:
  1. Severe secondary dysmenorrhoea (typically initiating several days prior to menses, worsening progressively, and unresponsive to standard non-steroidal analgesics).
  2. Deep dyspareunia (pain with deep penetration due to stretching of involved uterosacral ligaments or the rectovaginal septum).
  3. Chronic non-cyclical pelvic pain and subfertility (due to pelvic adhesions, distorted tubal architecture, and an inflammatory peritoneal microenvironment).
  • Associated cyclical symptoms: Dyschezia (painful defecation during menses), cyclical dysuria, haematuria, or cyclical rectal bleeding.
• Bimanual and Speculum Examination Findings:
  • Fixed, retroverted uterus due to posterior cul-de-sac obliteration and adhesions.
  • Exquisite tenderness and palpable nodularity along the uterosacral ligaments or in the pouch of Douglas (rectovaginal septum).
  • Visible bluish-black "powder-burn" nodules in the posterior vaginal fornix on speculum inspection.
  • Fixed, tender adnexal masses representing ovarian endometriomas ("chocolate cysts").

Diagnostic Pathway

• High-Resolution Transvaginal Ultrasound: Modern specialized endometriosis ultrasound protocols assess the "sliding sign" (mobility between the anterior rectum and posterior uterine wall) to detect pouch of Douglas obliteration. TVUS reliably identifies ovarian endometriomas (homogeneous low-level "ground-glass" internal echogenicity with no internal vascularity on Doppler) and deep infiltrating endometriosis (DIE) involving the bladder, bowel, and uterosacral ligaments.
• Endometriosis diagnosis: Symptoms and appropriate imaging can support a clinical diagnosis and empirical treatment. Normal imaging does not exclude superficial disease. Laparoscopy, with histology when lesions are sampled, is useful when indicated, but is not mandatory before every diagnosis or treatment.

Management Paradigm

1. First-Line Medical Therapy:
   • Analgesia: Non-steroidal anti-inflammatory drugs (NSAIDs, e.g., mefenamic acid $500\text{ mg}$ TDS or naproxen $500\text{ mg}$ BD) taken regularly at onset of symptoms to inhibit cyclooxygenase-mediated prostaglandin synthesis.
   • Hormonal Suppression: Combined oral contraceptives taken continuously (suppressing the pill-free withdrawal bleed) to induce anovulation and decidualize endometriotic tissue. Alternatively, high-dose progestogens (dienogest $2\text{ mg}$ daily, norethisterone, or depot medroxyprogesterone acetate).
   • Levonorgestrel Intrauterine System ($52\text{ mg}$ LNG-IUS): Markedly suppresses local endometrial proliferation, reduces menstrual volume, and significantly decreases dysmenorrhoea and pelvic pain.
2. Second-Line Medical Therapy (Specialist Care):
   • GnRH Agonists (e.g., goserelin $3.6\text{ mg}$ subcutaneous implant monthly) or GnRH Antagonists (e.g., relugolix): Induce profound hypogonadotrophic hypogonadism. To prevent severe vasomotor symptoms, vaginal atrophy, and accelerated bone mineral density loss, "add-back" therapy (low-dose oestrogen plus progestogen) is mandatory if therapy extends beyond 6 months.
3. Surgical Management:
   • Conservative Laparoscopic Excision / Ablation: Complete excision of peritoneal lesions, division of adhesions, and restoration of normal pelvic anatomy. For ovarian endometriomas, laparoscopic cystectomy (stripping the cyst wall) is superior to simple drainage and electroablation in reducing pain recurrence, lowering cyst recurrence, and improving spontaneous pregnancy rates.

• Endometriosis surgery: Consider symptoms, fertility, ovarian reserve and prior treatment. Hysterectomy with or without removal of ovaries is an individual specialist decision and may not eliminate every pain source. Removing ovaries causes surgical menopause; cystectomy can reduce ovarian reserve and is not automatically indicated before IVF.

Pelvic-pain decision example

A patient with chronic cyclical pain and deep dyspareunia can discuss empirical endometriosis treatment after appropriate assessment, even when ultrasound is normal. Persistent symptoms or fertility concerns may lead to laparoscopy and specialist planning. This differs from acute severe unilateral pain with vomiting, which raises torsion and requires urgent assessment. In someone with heavy bleeding and an enlarged tender uterus, adenomyosis is considered, but persistent intermenstrual bleeding or endometrial risk still requires the appropriate sampling pathway. One plausible benign diagnosis must not prevent investigation of a separate warning sign.

Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome is the most prevalent endocrine disorder of reproductive-aged women, affecting 8% to 13% of Australian women. It is characterized by chronic anovulation, hyperandrogenism, and metabolic dysregulation.

Primary references (checked 7 October 2026): 2023 international PCOS guideline.