Breast Histiocytoid Carcinoma

**Semantic type:** Neoplastic Process

**Definition:** A rare variant of invasive lobular breast carcinoma characterized by the presence of histiocyte-like malignant cells with pale cytoplasm forming sheets or linear patterns. Apocrine differentiation may be present. It usually has an aggressive clinical course.

**Synonyms:** - HBC - Histiocytoid Breast Carcinoma - Histiocytoid Breast Carcinoma - Histiocytoid Lobular Breast Carcinoma - Infiltrating Histiocytoid Breast Carcinoma - Infiltrating Histiocytoid Lobular Breast Carcinoma - Invasive Histiocytoid Breast Carcinoma - Invasive Histiocytoid Lobular Breast Carcinoma