Endometrial hyperplasia

Endometrial hyperplasia (EH) refers to an abnormal proliferation of endometrial stromal and glandular components. It represents a spectrum of endometrial changes ranging from cystically dilated glands to cellular atypia.

One of the main concerns with imaging on ultrasound and MRI is attempting to differentiate endometrial hyperplasia from endometrial carcinoma.

Clinical presentation

A great majority of patients present with abnormal uterine bleeding.

Please add more content.

Pathology

Hyperplasia represents a spectrum of endometrial changes ranging from glandular atypia to frank neoplasia.

There are several types of endometrial hyperplasia, which include:

• cystic endometrial hyperplasia: this form of endometrial hyperplasia is the most common and most benign
• adenomatous endometrial hyperplasia
• atypical endometrial hyperplasia

Hyperplasia can be also classified into two broad groups ⁵:

• hyperplasia without cellular atypia
• hyperplasia with cellular atypia

Unopposed oestrogen stimulation (either from an endogenous or exogenous source) is implicated in its pathogenesis.

Associations

• obesity
• pregnancy (and ectopic pregnancy)
• oestrogen secreting ovarian tumours
  • granulosa cell tumour of the ovary

Radiographic features

Ultrasound

Endometrial hyperplasia is considered wheneverImaging the endometrium is on days 5-10 of a woman's cycle reduces the variability in endometrial thickness.

• premenopausal
  • normal endometrial thickness depends on the stage of the menstrual cycle, but a thickness of >10;15 mm in thickness, especiallyis considered top normal in menopausal patients, although itthe secretory phase
  • hyperplasia can be reliably excluded in these patients only when the endometrium measures less than 6 mm ¹. In
• postmenopausal patients
  • a thickness of >5 mm is considered abnormal.

The appearance can be non-specific and cannot reliably allow differentiation between hyperplasia and carcinoma ⁵. Usually there is a homogeneous increase in endometrial thickness, but endometrial hyperplasia may also cause asymmetric/focal thickening with surface irregularity, an appearance that is suspicious for carcinoma.

Pelvic MRI

• T2: hyperplasia is often isointense to hypointense to normal endometrium ⁷

Treatment and prognosis

Up to one-third of endometrial carcinoma is believed to be preceded by hyperplasia. Biopsy is required for a definitive diagnosis.

Because endometrial hyperplasia has a non-specific appearance, any focal abnormality should lead to biopsy if there is clinical suspicion for malignancy.

Biopsy is often required for a definitive diagnosis (e.g, vaginal bleeding).

Differential diagnosis

On ultrasound, appearances can potentially simulate:

• normal thickening during the secretory phase: see endometrial thickness
• sessile endometrial polyp(s): may contain cystic spaces ⁴
• submucosal uterine fibroids
• endometrial cancer
• adherent intrauterine blood clot
• pregnancy (and ectopic pregnancy)

See also

• abnormal thickening of the endometrium