What Is Carcinoma?
Carcinoma is any cancer that arises from epithelial cells. It is malignant by definition: carcinomas invade surrounding tissues and organs, and may spread to lymph nodes and distal sites (metastasis). Carcinoma in situ (CIS) is a pre-malignant condition, in which cytological signs of malignancy are present, but there is no histological evidence of invasion through the epithelial basement membrane.
Types of Carcinoma
Carcinoma, like all neoplasia, is classified by its histopathological appearance. Adenocarcinoma and squamous cell carcinoma, two common descriptive terms for tumours, reflect the fact that these cells may have glandular or squamous cell appearances respectively. Severely anaplastic tumours might be so undifferentiated that they do not have a distinct histological appearance.
Some of the most common carcinomas are: basal cell carcinoma, squamous cell carcinoma, renal cell carcinoma, small cell carcinoma, cervical carcinoma, hepatocellular carcinoma, ductal carcinoma, transitional cell carcinoma, adenoid cystic carcinoma, merkel cell carcinoma, neuroendocrine carcinoma, papillary carcinoma, bronchogenic carcinoma...
Sometimes a tumour is referred to by the presumptive organ of the primary (eg carcinoma of the prostate) or the putative cell of origin (hepatocellular carcinoma, renal cell carcinoma).
Source: Carcinoma - Wikipedia