Final answer:
Invasive/Infiltrating Carcinoma of No Special Type was previously known as Invasive Ductal Carcinoma. This invasive tumor is capable of invading surrounding tissues, distinct from non-invasive pre-malignancies. Carcinomas are classified by the cell type they resemble, and their malignancy is characterized by the ability to invade and form metastases.
Step-by-step explanation:
The Invasive/Infiltrating Carcinoma of No Special Type (NST) was previously known as Invasive Ductal Carcinoma (IDC). This form of cancer is an invasive tumor, implying that it has the capability to invade surrounding tissues, which is a defining property of invasive carcinomas. It differs from pre-malignancies (such as atypia, dysplasia, and carcinoma in situ) which are non-invasive but have the potential to progress to invasive cancer if left untreated.
Understanding different types of skin cancer, such as squamous cell carcinoma and basal cell carcinoma, is important. Squamous cell carcinoma affects the keratinocytes in the epidermis and can present as lesions, while basal cell carcinoma, the most common skin cancer, occurs in basal cells, is rarely metastatic, and responds well to treatment if caught early. Both of these carcinomas contrast with melanoma, which is a more serious type of skin cancer that affects melanocytes and is prone to metastasize.
Cancers, including carcinomas, are classified by the type of cell that the tumor resembles. The acquisition of the ability to invade neighbouring tissues and the ability to form metastases are classical properties of malignant tumors.