Thanks for the query. Lumps in the skin are not uncommon in general population but since in your case it's painful and increasing in size, it requires medical attention. Consider meeting a Dermatologist or plastic surgeon for physical examination. If needed an FNAC or skin biopsy can be done to ascertain the nature of this lump. Skin biopsy will be both diagnostic and therapeutic if it's done. Don't delay the consultation. Hope it helps.