Endometrial hyperplasia

What is endometrial hyperplasia?

Endometrial hyperplasia is broadly defined as an excessive cellular proliferation leading to an increased volume of endometrial tissue. It is characterised by an increase in the endometrial gland-to-stroma ratio greater than 1:1.

Endometrial hyperplasia is further classified as simple or complex, with or without atypia. This classification system is based on the complexity and crowding of the glandular architecture.

The most common presenting symptom of endometrial hyperplasia is abnormal uterine bleeding, including:

However, endometrial hyperplasia can also be asymptomatic and can spontaneously regress without being detected.

Histological classification of endometrial hyperplasia

Aetiology and risk factors

Oestrogen stimulates endometrial proliferation.A relative excess of oestrogen (exogenous or endogenous) compared with progesterone is considered to be one of the principle causes in endometrial hyperplasias.

Key risk factors in post-menopausal women include:

• Unopposed oestrogen^,
• Obesity, particularly in nulliparous women^,

Other risk factors include:

• Diabetes^,
• Hypertension
• Polycystic ovary syndrome^,

Incidence and diagnosis

Mirena® Prescribing Information 

Efficacy and safety profile

The efficacy of Mirena^® in preventing oestrogen-induced hyperplasia in peri-menopausal and postmenopausal women has been assessed in various studies.