Diagnostic Mammography

Authors: Dr Helen Frazer*
                            A/Prof Liz Wylie *

What is diagnostic mammography?

Diagnostic mammography is a term describing the situation where a mammogram is carried out in a symptomatic patient; that is, a patient who has signs or symptoms of breast cancer, such as a palpable lump, nipple discharge, skin changes and so on.

It differs from screening mammography in that the patients undergoing a screening mammogram are, by definition, asymptomatic and hence have a lower probability of a cancer being present.

What are the generally accepted indications for a diagnostic mammogram?

Diagnostic mammography is the recommended first investigation for a woman over the age of 40 years with significant, new breast symptoms.1 Diagnostic mammography is part of the ‘triple test’, which includes a clinical examination and a needle biopsy of any pathological findings.

What are the prerequisites for having diagnostic mammography done?

The patient must be able to provide verbal and informed consent for the procedure. There should be symptom/s or clinical concern indicating possible breast pathology (asymptomatic patients should undergo screening mammography).

What are the absolute contraindications for diagnostic mammography?

There are no absolute contraindications for diagnostic mammography.

What are the relative contraindications for diagnostic mammography?

Diagnostic mammography is rarely carried out in women aged younger than 30 years, because of the high radiographic density and radiation sensitivity of the breast tissue. Pregnancy and breast-feeding are also relative contraindications due to the adverse effects of exposure to radiation. Lactating breasts are more sensitive to radiation, with regard to the likelihood of cancer being induced, compared with the breasts of women who are not breast-feeding. However, this small risk must be balanced against the risk of missing the diagnosis of breast cancer, as breast cancer does sometimes occur in pregnant and breast-feeding women. Radiation protection measures can be put in place to obtain mammograms for these patients.

What are the adverse effects of diagnostic mammography?

The risk of getting breast cancer from diagnostic mammography is very low. Very occasionally, bruising or splitting of the skin occurs. Breast implant rupture has been reported during mammography; however, it is extremely uncommon.

The Health Protection Agency of the United Kingdom estimates the risk of an additional cancer in a lifetime from a single mammographic examination to be in the low-risk range: 1 in 100,000 to 1 in 10,000.2 This is the same risk of developing any cancer as that which arises from exposure to the natural background radiation accumulated from the normal environment in 1 year.

Is there any specific post procedural care required following a diagnostic mammography?

There is no specific postprocedural care required.

Are there alternative imaging tests, interventions or surgical procedures to diagnostic mammography?

For women with a palpable lump, it is important to note that mammography does not detect all breast cancers, even when the cancer has caused a lump that can be felt. In such a circumstance, a normal mammogram does not mean that the lump can be ignored. In this situation, other diagnostic tests, such as breast ultrasound, fine-needle aspiration (see InsideRadiology: Breast FNA) or vacuum-assisted core biopsy (see InsideRadiology: Core Biopsy), may be necessary to find out the cause of the lump.

Further information about diagnostic mammography:

Tomosynthesis (3D mammography) is now available in many practices. Tomosynthesis is particularly helpful in detecting stellate breast lesions, and is moderately more sensitive than conventional digital mammography.

Reference:

1. Cancer Australia – Investigation of a new breast symptom – a guide for general practitioners
2. The Health Protection Agency, X-rays – How safe are they?, May 2001, https://www.phe-protectionservices.org.uk/cms/assets/gfx/content/resource_3317cs2c758933af.pdf

*The author has no conflict of interest with this topic.

Page last modified on 31/8/2018.