Teaching Case

A 59-year-old woman, with no symptoms and no relevant abnormalities at physical examination, underwent a routine gynaecological ultrasound that showed an endometrial thickening.
An endometrial biopsy was performed and pathological diagnosis was serous papillary endometrial cancer.
The patient was referred to our institution for endometrial cancer staging and treatment planning.

A magnetic resonance (MRI) protocol for staging endometrial cancer was performed which included: axial T2-weighted images (T2WI) and diffusion-weighted images (DWI) sequences of the abdomen; axial T1-weighted images (T1WI), T2WI and DWI of the pelvis; sagittal T2WI of the pelvis; axial oblique (perpendicular to the endometrial cavity) T2WI and DWI; axial oblique dynamic multiphase and late phase contrast-enhanced (perpendicular to cervix) sequences.
MRI depicted a normal-sized uterus with bright foci and cyst-like inclusions on T2WI, predominantly in the inner myometrium, related to adenomyosis, and polypoid endometrial cancer. The presence of adenomyosis impairs the evaluation of the depth of myometrial invasion. There were no signs of deep myometrial invasion nor cervical stroma invasion. Neither suspicious lymph nodes nor peritoneal metastases were identified.
The ovaries had normal morphology and signal intensity in all sequences.

Endometrial cancer is the most common gynaecological malignancy in developed countries. The majority of the cases occur between ages 55 and 65 and white women are more frequently affected. [1]

The vast majority of patients presents with abnormal vaginal bleeding. Less often, patients present with pelvic pain or pressure or atypical glandular cells on cervical cytology. [2]
Several risk factors have been associated with endometrial cancer, such as unopposed oestrogen intake, nulliparity, obesity, diabetes and use of tamoxifen. [1]
Although endometrial cancer is staged on the basis of surgico-pathological findings, pre-operative magnetic resonance imaging (MRI) is recommended.

The first line imaging method in the evaluation of abnormal vaginal bleeding is transvaginal ultrasound. [2]
On morphologic MRI sequences, endometrial cancer is often heterogeneous, with intermediate to hyperintense on T2WI and isointense to the endometrium on T1WI. [2]
The use of only morphologic sequences in the evaluation of the depth of myometrial invasion may be limited in the presence of pitfalls, specifically, the loss of junctional zone definition, myometrial stretching with a polypoid tumour, leyomiomas, adenomyosis and poor tumour to myometrium contrast. [1] As a result, functional MRI sequences – dynamic multiphase contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DWI) are recommended nowadays.
The ideal phase for assessment of the depth of myometrial invasion is in the equilibrium phase (2 minutes post injection), when there is maximum tumour to myometrium contrast. [1] In this phase the tumour is hypointense to the myometrium. [2] The tumour shows restricted diffusion, with high signal intensity on high b-value sequences and low signal intensity on the respective ADC map. [2] Potential pitfall may occur in areas of retained mucus, coagulative necrosis and abscesses. Well differentiated tumours may not exhibit restricted diffusion. [1]
DWI may be limited due to its low spatial resolution and poor anatomic detail. Fused T2WI and DWI may overcome these limitations, providing simultaneously anatomic and functional information on the tumour. [3] Fused T2WI and DWI has had good results in gynaecological cancer compared to T2WI alone.

In stage I disease, hysterectomy with bilateral salpingo-oophorectomy is always performed. Bilateral pelvic para-aortic lymphadenectomy is advised in stages IA G3 and IB G1, G2 and G3. Depending on the risk assessment, vaginal brachytherapy, pelvic radiation therapy and chemotherapy may be indicated. [4]

In pre-operative planning it is pivotal to know the histological grade – determined at endometrial biopsy - and depth of myometrial invasion – assessed in MRI.