Lipoma

It is benign tumor arising from the yellow fat. When it arises from brown fat, it is called hibernoma.
It is called as universal tumor (ubiquitous tumor) as it can occur anywhere in the body.

Types :
Painful lipomas are called neurolipomas.
Dercum's disease is tender deposition of fat especially on the trunk, is also called as adiposis dolorosa.
Fibrolipomas -with fibrous component
Naevolipoma - with telengiectasias

Sites :
Subcutaneous
Intramuscular
Intermuscular
Subfascial
Subdural
Parosteal
Submucosal
Subsynovial

Clinical features :
Localised swelling, which is lobular and non tender
Semifluctuant
Mobile (slip sign )
Skin is free
Pedunculated at times

Differential diagnosis :
Neurofibroma
Cystic swellings

Complications :
Sarcomatous change
Myxomatous change
Saponification
Calcification

Treatment :
Excision