A xanthogranuloma is a nodule
or benign tumor
that contains granulation tissue with fat deposits in it.
(xantho = fat, granul = granulation tissue, oma = tumor) it is difficult to tell you what it means and what it is caused by without knowing the locations of the lesions, other illnesses or organ involvement, your age or gender. You should call your doctor or the doctor who ordered the testing and speak with them. They have all your information and know why they ordered the testing, so they are the best person to interpret the results for you.