Invasive ductal carcinoma (IDC) is the most common type of breast cancer. It begins within the milk ducts of the breast and then extends into the surrounding breast tissue. Ultrasound imaging is a common tool for detecting and evaluating breast abnormalities.
Understanding Invasive Ductal Carcinoma
Invasive ductal carcinoma originates in the milk ducts. The “invasive” aspect signifies that these cancerous cells have breached the duct walls and spread into the nearby breast tissue. This type of cancer accounts for approximately 70% to 80% of all breast cancer diagnoses.
The disease often presents as a palpable lump in the breast or armpit, though it can also be detected through routine imaging before it is large enough to be felt. While the risk of IDC generally increases with age, it can affect younger women and men as well. The rate at which IDC progresses can vary significantly among individuals, influenced by factors such as the cancer’s type and grade.
The Role of Ultrasound in Detection
Ultrasound imaging utilizes high-frequency sound waves to create detailed pictures of the internal structures of the breast. A technician applies a gel to the breast and moves a small handheld device called a transducer over the skin. This transducer emits sound waves that travel through the breast tissue, bounce back as echoes, and are then captured to form an image on a computer screen.
Ultrasound can effectively differentiate between solid masses and fluid-filled cysts. It is also valuable for examining dense breast tissue, where mammograms may be less clear due to the high density of glandular tissue obscuring potential tumors. Ultrasound also serves as a follow-up when a suspicious finding is noted on a mammogram or a palpable lump is present.
What Invasive Ductal Carcinoma Looks Like on Ultrasound
On an ultrasound image, invasive ductal carcinoma displays specific characteristics. A common finding is an irregular shape and spiculated margins, meaning the edges appear jagged or spiky. The mass may also exhibit a “taller-than-wide” orientation, where its vertical dimension exceeds its horizontal measurement, indicating infiltration into surrounding tissues.
These suspicious lesions appear hypoechoic, meaning they are darker than the surrounding normal breast tissue. Another characteristic feature is posterior acoustic shadowing, a dark area behind the lesion, suggesting sound waves are absorbed or blocked by the dense tumor. While calcifications are more commonly detected by mammography, punctate calcifications can sometimes be observed within the mass on ultrasound, appearing as bright dots. The presence of increased vascularity, or blood flow, within or around the mass, can also strongly suggest malignancy.
Next Steps After a Suspicious Ultrasound Finding
When a breast ultrasound reveals a suspicious finding, the next step involves a biopsy to obtain tissue for pathological examination. A core needle biopsy is a common procedure where a hollow needle is used to extract small tissue samples from the area of concern. This procedure is often guided by ultrasound to ensure precise sampling of the abnormality.
The tissue samples collected during the biopsy are then sent to a pathology lab to determine if cancer cells are present. If the biopsy confirms a diagnosis of invasive ductal carcinoma, additional imaging modalities such as mammography or magnetic resonance imaging (MRI) may be used for further evaluation or to determine the extent of the cancer. Follow-up and consultation with a healthcare provider are important to discuss the biopsy results and plan any necessary further steps.