What is a carcinoma tumor?

Carcinoma is a type of cancer that produces cancerous tumors throughout much of the body, according to WebMD. This type of cancer begins in the cells that line organs or that make up the skin.

Carcinoma cancers can occur throughout much of the body, states WebMD. However, the most common carcinomas include basal cell carcinoma, squamous cell carcinoma and renal cell carcinoma. Basal cell carcinoma and squamous cell carcinoma both refer to cancers that affect the skin. Both types can spread to other parts of the body and become very serious. Renal cell carcinoma affects the kidneys and can also spread throughout most of the body.