Carcinoma is a type of what?
Invasive carcinoma of no special type Invasive carcinoma of no special type Invasive carcinoma of no special type (NST) also known as invasive ductal carcinoma or ductal NOS and previously known as invasive ductal carcinoma, not otherwise specified (NOS) is a group of breast cancers that do not have the "specific differentiating features". Those that have these features belong to other types. In this group are: pleomorphic carcinoma, carcinoma with osteoclast-like stromal giant cells, carcinoma with choriocarcinomatous features, and carcinoma with melanotic features. It is a diagnosis of exclusion, which means that for the diagnosis to be made all the other specific types must be ruled
Metaplastic carcinoma The epithelial-type is further classified as squamous cell carcinoma, adenocarcinoma with spindle cell differentiation, and adenosquamous carcinoma. The mixed-type is further classified as carcinoma with chondroid metaplasia, carcinoma with osseous metaplasia, and carcinosarcoma. Wargotz et al. proposed a classification system for MCB according to its cytopathological features. These classifications are spindle cell, squamous cells, matrix-producing, carcinosarcoma, and MCB with osteoclastic giant cell. Another research group, Oberman et al., proposed a classification system consisting of spindle cell carcinoma, invasive ductal carcinoma with extensive squamous metaplasia, and invasive ductal carcinoma with pseudosarcomatous metaplasia. The lack of consensus between these various classification systems