Endometrial hyperplasia
Dr Rohit Sharma and Dr Yuranga Weerakkody ◉ et al.
Endometrial hyperplasia is abnormal proliferation of the endometrial glands and stroma, defined as diffuse smooth thickening >10 mm One of the main concerns is the potential malignant transformation of the endometrial hyperplasia to endometrial carcinoma.
Epidemiology
Endometrial hyperplasia affects women of all age groups
Clinical presentation
A great majority of patients present with abnormal vaginal bleeding.
Pathology
Hyperplasia with increased gland-to-stroma ratio; there is a spectrum of endometrial changes ranging from glandular atypia to frank neoplasia.
There are several types of endometrial hyperplasia, which include:
simple hyperplasia without atypia also known as cystic endometrial hyperplasia
simple hyperplasia with atypia
complex hyperplasia without atypia
complex hyperplasia with atypia
Hyperplasia can be also classified into two broad groups
hyperplasia without cellular atypia
hyperplasia with cellular atypia
Associations
Unopposed oestrogen stimulation (either from an endogenous or exogenous source) is implicated in its pathogenesis; some of these conditions include:
obesity
polycystic ovary syndrome
pregnancy (and ectopic pregnancy)
oestrogen-secreting ovarian tumours
granulosa cell tumour of the ovary
tamoxifen
Radiographic features
Ultrasound
Imaging the endometrium 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 >15 mm is considered the upper limit of normal in the secretory phase
hyperplasia can be reliably excluded in patients only when the endometrium measures less than 6 mm
postmenopausal
a thickness of >5 mm is considered abnormal
The appearance can be non-specific and cannot reliably allow differentiation between hyperplasia and carcinoma
Usually, there is a homogeneous smooth increase in endometrial thickness, but endometrial hyperplasia may also cause asymmetric/focal thickening with surface irregularity, an appearance that is suspicious for carcinoma. Cystic changes can also be seen in endometrial hyperplasia.
Ultrasound features that are suggestive of endometrial carcinoma as opposed to hyperplasia include
heterogeneous and irregular endometrial thickening
polypoid mass lesion
intrauterine fluid collection
frank myometrial invasion
MRI
T2: hyperplasia is often isointense to hypointense to normal endometrium
Treatment and prognosis
Up to one-third of endometrial carcinoma is believed to be preceded by hyperplasia. A 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 (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
submucosal uterine fibroids
endometrial cancer
adherent intrauterine blood clot
pregnancy (and ectopic pregnancy)
incomplete abortion