Regular physical examinations and maintaining an accurate medical history are important for maintaining good health, especially when screening for cancer. When ductal carcinoma is identified in its earliest stages, survival rates dramatically increase and therapies are often much more tolerable.

Most cases of ductal carcinoma are diagnosed after a screening mammogram. Mammograms provide x-ray images of breast tissue that may identify abnormalities before they can be felt by the patient or a physician. Mammograms can identify tumors and tiny calcium deposits called microcalcifications, which are characteristic of ductal carcinoma.

In its earliest stages, ductal carcinoma in situ (DCIS) appears only on the mammogram as tiny specks or calcifications. These specks are the buildup of degenerated material left from dead cancer cells, which often become calcified. In contrast, invasive ductal carcinoma normally forms a hard lump and can be felt as well as detected by a mammogram. Although mammograms often offer the best way to detect ductal carcinoma at its earliest stages, they may produce false negatives or occur at too broad an interval to detect a fast spreading cancer.  False positives also may occur.

The National Cancer Institute (NCI) recommends that all women age 40 or older receive mammograms every one to two years. Women who are at greater risk for breast cancer may be advised to have mammograms performed more frequently. Women younger than 40 who are at an elevated risk for breast cancer should discuss their risk factors and screening needs with their physician.

In addition to mammograms, clinical breast examinations and breast self-examinations (BSE) are two more ways to screen for breast cancer. The clinical breast examination, which takes about 10 minutes, is performed by a physician or other healthcare provider who palpates the breasts with the pads of the fingers. Using this method, the entire breast area will be checked for signs of cancer, including under the arms, around the collarbone area and the nearby lymph nodes. Many women perform a BSE every month to check for possible changes in their breasts. BSEs are intended to supplement but not replace clinical breast examinations or mammograms.

If mammogram results are inconclusive, a physician may send the patient for a breast ultrasound or magnetic resonance imaging (MRI) scan. When a clinical breast examination, mammogram or ultrasound shows an area of possible concern, a breast biopsy is typically performed. A biopsy involves the removal of cells or tissues for analysis under a microscope by a pathologist. The pathologist can determine whether or not the cells are cancerous and specifics about the type of tumor, which may provide information for treatment planning.

Ductal lavage is another technique that may be used for some women at high risk for breast cancer. With this procedure, the physician inserts a tiny catheter into the lining of a duct within the breast. Through the catheter, a sample of cells can be removed and examined for changes that take place before tumors can be detected by a mammogram. Ductal lavage may be more useful to identify women at risk rather than diagnose the disease. Some studies of women already diagnosed with breast cancer have produced ductal lavages that showed no abnormalities.

Other tests may be performed to determine if cancer has spread to other areas. These may include chest x-rays to examine the lungs and CT scans or PET scans.