Breast Lobular Carcinoma In Situ

**Semantic type:** Neoplastic Process

**Definition:** A non-invasive adenocarcinoma of the breast characterized by a proliferation of monomorphic cells completely filling the lumina. The overall lobular architecture is preserved. It is frequently multifocal (90% in some series) and bilateral. It seldom becomes invasive; however there is an increased risk of infiltrating ductal adenocarcinoma.

**Synonyms:** - LCIS - LCIS - LCIS, NOS - Lobular Breast Carcinoma In Situ - Lobular Breast Carcinoma In Situ - Lobular Ca in situ of Breast - Lobular Ca in situ of the Breast - Lobular Carcinoma In Situ (LCIS) - Lobular Carcinoma In Situ of the Breast - Lobular Carcinoma In Situ of the Breast (LCIS) - Lobular Carcinoma in situ - Lobular Carcinoma in situ of Breast - Lobular carcinoma in situ - Lobular carcinoma in situ of breast - Lobular carcinoma in situ of unspecified breast - Lobular carcinoma in situ, NOS - Non-Infiltrating Lobular Breast Carcinoma - Non-Infiltrating Lobular Carcinoma - Non-Infiltrating Lobular Carcinoma of Breast - Non-Infiltrating Lobular Carcinoma of the Breast - Non-Invasive Lobular Breast Carcinoma - Non-Invasive Lobular Carcinoma of Breast - Non-Invasive Lobular Carcinoma of the Breast - lobular carcinoma in situ