text: they are very common benign tumors (the most common tumor in women) of the smooth muscle tissue in the muscular layer of the uterus. They are a celular proliferation of fusiform cells  with very low mitotic activity that usually arise in several groups.\n\nThey are benign, I insist, because they are well limited and have little or no mitotic activity (cell division), which isn't irregular either (the DNA does not get mutated when they divide). they may cause bleeding or discomfort, which is why the woman should go to her gyno. surgical treatment is usually completely curative and doesn't involve any loss of function (as in a histerectomy or anything).