I have a large lump that Ive had on my leg for years and sometimes it swells but yesterday I noticed that it had a dark opening the size of and ball point pin tip. I was able to sanitze a needle and entered into the hole with it. It wasn't painful as if it has been opened up for a long time and it left a half inch deep hole into the center of the cyst. I cleaned it with alcohol and I proceeded to purge the discharge out of the hole and out came this black thick hard substance. Thicker than paste and dark brown or black in color and very smelly. Is this something that can be medicated with over the counter medicine?