Tubular carcinoma doesn't always have obvious symptoms in the breast. The following are symptoms you may have and the ways doctors make a diagnosis.
Signs and symptoms
Like other types of breast cancer, tubular carcinoma of the breast may not cause any symptoms at first. Over time, a lump may grow large enough to be felt during breast self-exam or examination by a doctor. Tubular carcinomas are usually small — 1 cm or less in diameter — and feel firm or hard to the touch.
Most tubular carcinomas are first detected by a screening mammogram or during breast examination. On a mammogram, it can be very hard to tell the difference between a tubular carcinoma and a true invasive ductal carcinoma. Like invasive cancers, most tubular carcinomas have "spiculated" margins, meaning that they appear to have thin lines radiating out from the tumor. Further testing is needed to tell for sure whether a mass is truly a tubular carcinoma.
Diagnosing tubular carcinoma usually involves a combination of steps:
- A physical examination of the breasts. Your doctor may be able to feel the lump in the breast, or you may feel it yourself during a breast self-exam.
- A mammogram can locate the tumor and check for evidence of cancer in both the affected breast and the other breast.
- MRI, ultrasound, or both may be used to obtain additional images of the breasts and check for other areas of cancer.
- Biopsy. A biopsy involves taking out some or all of the tumor to look at it under the microscope. The sample can be taken by inserting a fine needle through the skin of the breast or making a small incision. Biopsy is the key to accurate diagnosis, because imaging tests alone can't distinguish tubular carcinoma from other types of breast cancer and benign (noncancerous) breast conditions.
When a pathologist examines the tumor samples under a microscope, he or she looks for the tube-shaped structures that give tubular carcinoma its name. Experts generally agree that more than 90% of the tumor must have this characteristic appearance in order to be called "pure" tubular carcinoma. If it doesn't, then it is diagnosed as a "mixed" tubular carcinoma. The more "tubular" it is, the less likely it is to spread and the easier it should be to treat.
Most tubular carcinomas do have a small amount of another type of breast cancer, called ductal carcinoma in situ or DCIS, within or next to the mass. Less often, doctors may find a lobular carcinoma in situ (LCIS, a precancerous condition confined to the lobule) next to or near the tubular carcinoma. Research also suggests there is some risk of finding other cancerous areas within the same breast once a tubular carcinoma is diagnosed.
In addition, individual studies have found that anywhere from 4.5-38% of women with tubular carcinoma in one breast also have cancer in the other breast. The cancer in the other breast is usually invasive ductal carcinoma (IDC), the most common type of breast cancer. This is why it's so important to have both breasts checked thoroughly.
The tissue should be tested for some other important features of a true tubular carcinoma of the breast:
- Hormone-receptor-positive (HR+) status: Studies show that tubular carcinomas test positive for estrogen receptors 70-100% of the time and for progesterone receptors about 60-83% of the time.
- HER2-negative (HER2-) status: Tubular carcinomas usually test negative for receptors for the protein HER2/neu.
Both of these features — along with tubular carcinoma's tendency to be small and stay within the breast — help explain why you may hear your doctor say that tubular carcinoma has a "favorable prognosis" or "good outlook." HR+/HER2- cancers tend to be less aggressive cancers. Research also suggests that tubular carcinomas are much less likely to have the chromosomal abnormalities typically found with invasive breast cancers. (Chromosomes are the threadlike structures that contain cells' genetic material.)
As with the other less common types of breast cancer, diagnosing tubular carcinoma takes special skill. You may want to ask for a second opinion if this is your diagnosis. You also can ask for repeat testing if you're told you have a tubular carcinoma that is hormone-receptor negative or HER2-positive.
For more information about how breast cancer is diagnosed, see Your Diagnosis.