Giantism is a rare endocrine disorder caused by excessive secretion of growth hormone (GH) during childhood. Giantism is the result of somatotropic cells hyperplasia and it's characterized by abnormal length and height .
An endocrinologist is a doctor who specializes in hormone diseases, metabolism and nutritional problems.
Remember that for the proper selection of health professional that treats giantism you must consider the nature, severity and symptoms you are presenting.