<unk>  <unk>  is an incidental microscopic finding with characteristic cellular morphology and multifocal tissue patterns. The condition is a laboratory diagnosis and refers to unusual cells in the lobules of the breast. The lobules and acini of the terminal duct-lobular unit (TDLU), the basic functional unit of the breast, may become distorted and undergo expansion due to the abnormal proliferation of cells comprising the structure. These changes represent a spectrum of atypical epithelial lesions that are broadly referred to as lobular neoplasia (LN). One subset of LN can be defined as<unk>  based on specific cellular traits and tissue changes seen histologically. These lesions are preceded by atypical lobular hyperplasia and may follow a linear progression to invasive lobular carcinoma (ILC), with specific genetic aberrations. This process coincides with the progression of ductal neoplasia to ductal carcinoma in<unk>  and invasive carcinoma. Rarely, terminal ducts may be involved in lobular neoplasia, known as pagetoid spread. Many do not consider<unk>  to be a true case of cancer, but it can indicate an increased risk of future cancer. In 2018, the eighth edition of the American Joint Committee on Cancer (AJCC) removed<unk>  from tumor staging and considers it a benign entity.
Lobular carcinoma in situ
Ductal carcinoma in situ
Sister Mary Joseph nodule
Invasive lobular carcinoma
Invasive carcinoma of no special type
Lymphoepithelioma-like carcinoma
Focal nodular hyperplasia
Atypical ductal hyperplasia