What is the definition of Lobular Hyperplasia - Atypical Lobular Hyperplasia (ALH)/ Lobular Carcinoma in Situ (LCIS?)

ALH and LCIS together are called lobular neoplasia
Proliferation of atypical lobular cells in the terminal ductal lobular unit.
Lobular cells lack a cell surface adhesion molecule called E-cadherin, differentiating them from atypical ductal cells which have E-cadherin.
ALH is when <=50% of the acini are distended and LCIS is when >50% are distended.