Infiltrating Carcinoma of No Special Type

Abstract

Infiltrating breast carcinoma is a category of malignant epithelial tumors characterized by adjacent tissue invasion and distance metastasis. This category includes several microscopic types that differ from one another from morphological, immunohistochemical, molecular, and prognostic points of view. It is currently known that all these microscopic types have their origin in the terminal duct/lobular unit. The WHO 2012 classification categorized both invasive carcinomas of no special type (NST), previously termed as ductal carcinomas, and lobular and other special and rare subtypes of carcinomas, as infiltrating epithelial tumors, only distinguishing between these types in terms of morphological appearance, but disregarding the origin of proliferation [1].