The lump you have could be an epitrochlear lymph node. Lipomas and neuromas and other-omas can also produce similar lumps. Pulsatile lumps are usually vascular. Sebaceous cysts are usually adherent to skin but not underlying tissue. there are different sorts of Lipomas, some are small,hard and encapsuled others are a bit bigger,softer and not encapsuled.
Lipomas aren't dangerous, but you should go to a doc and get it checked just to make sure what it is.