Hypoglycemia, hypocalcemia, hypercholesterolemia, and hyperlipidemia are the constant features. Fetal hyperinsulinism is believed to be involved. The initial normal or even subnormal growth early in infancy eventually evolves into accelerated bone maturation and somatic gigantism. Intelligence is frequently normal but mental retardation was observed in some cases. Bone age is usually advanced.
Some patients develop hemihypertrophy.
Most cases are sporadic but other are transmitted as an autosomal dominant trait, some of which are familial. Malignant tumors include nephroblastoma, adrenal cortex carcinoma, hepatoblastoma, hepatocellular carcinoma, glioblastoma, neuroblastoma, rhabdomyosarcoma, lymphoma, and teratoma. Benign tumors include adrenal adenoma, carcinoid tumor, fibroadenoma, hamartoma, ganglioneuroma, and myxoma.