Cervical carcinoma

Carcinoma of the cervix is a malignancy arising from the cervix and is considered the third most common gynaecologic malignancy.

Epidemiology

It typically presents in younger women with the average age of onset at around 45 years. It is the third most common cancer in women worldwide.

Risk factors

• human papillomavirus (HPV) 16 and 18 infection: for most types except for clear cell carcinoma of the cervix and mesonephric carcinoma of the cervix
• multiple sexual partners or a male partner with multiple previous or current sexual partners
• young age at first intercourse
• high parity
• immunosuppression
• certain HLA subtypes
• oral contraceptives
• nicotine/smoking (except for cervical adenocarcinoma ²⁶)

Clinical presentation

Presenting symptoms include:

• vaginal bleeding
• vaginal discharge
• subclinical with an abnormality detected on Pap smear screening

Pathology

Invasive cervical carcinoma is thought to arise from the transformation of cervical intraepithelial neoplasia (CIN).

Histological types

The main histological types are:

• squamous cell carcinoma of the cervix: accounts for the vast majority (80-90%) of cases and is associated with exposure to human papilloma virus (HPV)
• adenocarcinoma of the cervix: rarer (5-20%) and can have several sub types which include ^11,20
  • clear cell carcinoma of the cervix
  • endometroid carcinoma of the cervix: ~7% of adenocarcinomas ²¹
  • mucinous carcinoma of the cervix
    • adenoma malignum: ~3% of adenocarcinomas
  • serous carcinoma of the cervix
  • mesonephric carcinoma of the cervix: ~3% of adenocarcinomas ²³
• neuroendocrine tumours of the cervix
  • small cell carcinoma of the cervix: rare (0.5-6%) ^18,22
• adenosquamous cell carcinoma of the cervix: rare

For a detailed overview, refer to:

• WHO histological classification of tumours of the uterine cervix

Location 

Cervical squamous cell carcinoma arises from the squamocolumnar junction while adenocarcinomas arises from the endocervix. This is situated on the ectocervix in younger patients though regresses into the endocervical canal with age. Hence cervical tumours tend to be exophytic in younger patients and endophytic with advancing age.

Radiographic features

General features

In order to be radiographically visible, tumours must be at least stage Ib or above (see staging). MRI is the imaging modality of choice to depict the primary tumour and assess local extent. Distant metastatic disease is best assessed with CT or PET, where available.

Although the FIGO staging system is clinically based, the revised 2009 FIGO staging encourages imaging as an adjunct to clinical staging. MRI can stratify patients to the optimum treatment group of primary surgery or combined chemotherapy and radiotherapy. Tumours stage IIa and below are treated with surgery.

Ultrasound

• hypoechoic, heterogeneous mass involving the cervix
• may show increased vascularity on colour Doppler
• although cervical cancer is staged clinically, ultrasound can be a useful adjunct by showing
  • size (<4 cm or >4 cm)
  • parametrial invasion
  • tumour invasion into the vagina
  • tumor invasion into adjacent organs
  • hydronephrosis: implies stage IIIB tumour.

CT

CT in general is not very useful in assessment of the primary tumour, but it can be useful in assessing advanced disease. It is performed primarily to assess adenopathy, but also has roles in defining advanced disease, monitoring distant metastasis, planning the placement of radiation ports, and guiding percutaneous biopsy.

On CT, the primary tumour can be hypoenhancing or isoenhancing to normal cervical stroma (~50% ¹⁹). 

PET-CT

PET-CT in conjunction with pelvic MRI is often used as an imaging strategy in helping stage cervical carcinoma.  

MRI

A dedicated MRI protocol is often useful for optimal imaging assessment.

The normal low signal cervical stroma provides intrinsic contrast for the high signal cervical tumour.

• T1: usually isointense compared with pelvic muscles
• T2
  • hyperintense relative to the low signal of the cervical stroma
  • hyperintensity is thought to be present regardless of histological subtype ¹

• T1 C+ (Gd)
  • contrast is not routinely used, though it may be helpful to demonstrate small tumours considered for trachelectomy
  • on contrast-enhanced T1-weighted images, tumour presents as a high signal relative to the low signal of the cervical stroma ²⁴

For further information, see the article: MRI reporting guidelines for cervical cancer.

Staging

The FIGO staging system is a most commonly adopted. See:cervical cancer staging

Treatment and prognosis

 Prognosis is affected by many factors which include:

• tumour stage
• volume of the primary mass
• histologic grade

Five-year survival rates vary between 92% for stage I disease and 17% for stage IV disease ¹⁸.

One of the keys roles of the radiologist is to help determine staging, as this may lead to appropriate management pathway either with surgery or chemo-radiotherapy. At the time of writing stage IIa vs. IIb is considered as a important separator in deciding whether a case is operable or not.

Differential diagnosis

For a mass involving the cervix consider:

• cervical polyp
• cervical leiomyoma
• invasion of the cervix from
  • primary uterine malignancy
  • vaginal cancer
• cervical lymphoma
• adenoma malignum: often considered a subtype of mucinous carcinoma of the cervix
• metastases to the cervix
• cervical ectopic pregnancy: consider with women of childbearing age with a high beta HCGβHCG