Let’s describe a sebaceous cyst that has not ruptured or become infected.
The lump will look skin coloured. The feel of the lump is at least as important as the look of it. The lump is fairly firm but not usually hard. The lump almost feels “underneath” the skin and you’ll be able to move the lump around.
There may be a tiny central plug at the top of the cyst. This is punctum represents the follicle from which the cyst developed.
The main alternative diagnosis to a sebaceous cyst is a lipoma. A lipoma is a benign fatty growth. The lipoma is usually softer and a little deeper than a cyst. The surface of a large lipoma may feel a little lumpy because the benign tumour consists of lumps of fat.