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Invasive Lobular Carcinoma (ILC)

Invasive Lobular Carcinoma (ILC), also known as infiltrating lobular carcinoma, is the second most common form of breast cancer diagnosed in the United States, representing 10-15 percent of diagnosed invasive breast cancers. This type of cancer is more difficult to see on imaging because of the way the cells stream through the breast tissue. Invasive lobular carcinomas are usually larger than expected from the mammogram. Most patients will have a breast MRI to get a better sense of the extent. Invasive lobular carcinomas are usually strongly estrogen receptor positive which makes them very sensitive to the anti-hormonal medications like tamoxifen. 

How is invasive lobular carcinoma (ILC) diagnosed?

Same Day Results

At the Johns Hopkins Breast Center, our team of breast specialists understands how quickly patients want results from a biopsy or scan if there is a suspicion of breast cancer, so we follow strict guidelines for biopsies and pathology reports. Patients are told the probability of cancer immediately following their biopsy procedure, and receive pathology confirmation within 24 hours.

Learn more about the steps of diagnosis, including:

  • Digital mammography
  • Ultrasound
  • MRI
  • Staging workup
  • Biopsy
  • Pathology

What is the treatment for invasive lobular carcinoma?

Women with a diagnosis of ILC must choose their surgeon carefully. For any breast cancer surgery to be a success, it’s important that the cancerous area is removed with a rim of normal breast tissue on every side. The branch-like growth pattern of ILC can make this difficult.

ILC is treated with a lumpectomy or mastectomy, depending on the size and location of the tumor. In addition, your medical oncologist and radiation oncologist may recommend chemotherapy and/or radiation. Hormonal therapy is nearly always part of the treatment for lobular cancers.

What is the prognosis for invasive lobular carcinoma?

Based on individual markers and prognostic factors including the staging of your tumor, your physician will provide you with information about your prognosis. Early stage breast cancers carry a higher survival rate than advanced stages. In general, with modern treatments, the prognosis of lobular carcinoma is similar to ductal carcinoma.