Our eyes meet fleetingly … I try my best to keep my facial expression calm so as not to instill panic in my patient … we move our attention back to the shocking ultrasound screen … a large mass, deep in her armpit, not seen on the mammogram and totally unexpected!
One of the most common questions my patients ask me, when they are taken through for an ultrasound examination of the breast is, “why am I having one, they didn’t do one previously?” I am a firm believer that the two examinations must be done together as far as possible for complete assessment of the breast, as the case in point shows! My patient had gone for previous mammograms, performed elsewhere, but never had an ultrasound. My examination was a life changing and lifesaving discovery.
So you ask:
“Why a mammogram?”, “Why an ultrasound?”
Let’s start with what they are. A mammogram is a low-dose x-ray of the breast, the worldwide, gold standard in screening for early breast cancer. Ultrasound, on the other hand, utilises high frequency sound waves (not radiation as used in x-rays) to detect lumps, cysts, glands, etc within the breast tissue and underarm area, and is used to complement mammogram findings. Sadly, ultrasounds are not always performed, for many reasons including time constraints and the patient having mainly fatty breast tissue (as opposed to dense, fibroglandular breast tissue).
A mammogram can detect cancer 3-5 years before a lump can be felt by you or your doctor! The main advantage of a mammogram is that of showing micro-calcifications (small calcifications) that can be a sign of early cancer (ductal carcinoma in situ or early invasive ductal cancer). This finding is not easily or completely seen on ultrasounds. The disadvantages of mammograms is that dense, pre-menopausal fibroglandular breast tissue (the hormone sensitive tissue of your reproductive life) is seen as white tissue and can mask – yes disguise or hide! – masses and cysts … hence the need for an ultrasound.
The advantage of ultrasound is that densities or lumps in your breast are better characterised on ultrasound; for example determining whether a white lump on the mammogram is a cyst or a solid mass. Lymph nodes are better assessed on ultrasound, and the nodes in the armpit are very important to check (as seen in my patient’s case). Glands grow and change appearance when there is infection, inflammation or cancer.
The use of both ultrasound and mammography is thus very important, each having different advantages, for the complete assessment of your breasts: the mammogram particularly for microcalcifications and the ultrasound to analyse breast tissue that may be dense on mammography and to characterise lumps.
The proof of a pudding is in the eating. My patient is now recovering after surgery for the lump and says:
“Doctor, thank goodness you did that ultrasound!”
Written by Dr Nadia Jajbhay