What type of tumor is a lipoma?

A lipoma is classified as a benign tumor of fat tissue. This type of tumor is composed of adipose (fat) cells and typically presents as a soft, movable lump under the skin. Lipomas are generally slow-growing and painless, and they do not invade surrounding tissues or metastasize, which is characteristic of benign tumors.

The nature of a lipoma is non-cancerous, distinguishing it from malignant tumors, which are aggressive, can invade nearby tissues, and may spread to other parts of the body. Additionally, lipomas are not cystic tumors filled with pus, as would characterize an abscess or other types of infectious or inflammatory conditions. They also do not originate from blood vessels, which would be the case with tumors such as hemangiomas.

Overall, the benign nature and specific composition of lipomas as fat tumors fundamentally define their classification in the realm of tumors.