Tags: Disease.
A mastocytoma or mast cell tumor is a type of round-cell tumor consisting of mast cells. It is found in humans and many animal species; in human medicine it also can refer to an accumulation or nodule of mast cells that resembles a tumor.Mast cells originate from the bone marrow and are normally found throughout the connective tissue of the body as normal components of the immune system. As they release histamine they are associated with allergic reactions.