Gigantism and dwarfism. Historical artwork of 18th century Scottish soldiers, one suffering from gigantism (Samuel McDonald, 1762-1802) and one from dwarfism (George Cranstoun). Gigantism (excessive growth) is caused by the overproduction of growth hormone, resulting from a tumour at its site of production, the pituitary gland. If untreated, the tumour may destroy the gland, resulting in death. Dwarfism (short stature) has a variety of causes, including hereditary disorders such as achondroplasia and hormonal disorders such as growth hormone deficiency.