Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Carcinoma of the breast, infiltrating lobular
Medically reviewed by Dr. Otari Nergadze, Neurosurgeon | Updated: January 2026
Carcinoma of the breast, infiltrating lobular: The second most common type of invasive breast cancer. Infiltrating lobular carcinoma starts in the glands that secrete milk (lobules). On a mammogram, a lobular carcinoma can look similar to a ductal carcinoma, appearing as a mass with fine spikes radiating from the edges (spiculation). Infiltrating lobular carcinoma can cause a thickening of the breast tissue. Lobular carcinoma can occur in more than one site in the breast or in both breasts at the same time. Treatment may include radiation, chemotherapy, and surgery.