Acrogigantism

Acrogigantism is a medical condition in which growth hormone (GH) secretion is excessive in children before the growth plates (epiphyseal plates) close, leading to rapid and extreme linear growth or gigantism. The term is used to describe GH excess beginning in childhood and is contrasted with acromegaly, which occurs after puberty when the growth plates have fused.

Most cases are due to a GH-secreting pituitary somatotroph adenoma or somatotroph hyperplasia. Less commonly, increased GH can result from hypothalamic disorders that raise GHRH (growth hormone–releasing hormone) levels, or from genetic conditions such as X-linked acrogigantism (X-LAG) caused by GPR101 duplication, as well as other syndromes like McCune-Albright and MEN1. The excess GH stimulates IGF-1 production, driving disproportionate growth of bones and soft tissues.

Clinical features include a rapid rise in height with a growth rate well above normal for age, enlarged hands and feet, prognathism, frontal bossing, thickened skin, and macroglossia. Patients may develop sleep apnea, joint pain, and metabolic disturbances such as insulin resistance and glucose intolerance. Puberty can be affected, and early diagnosis is important to limit final height and complications.

Diagnosis rests on biochemical and imaging findings. Serum IGF-1 is typically elevated for age, and an oral glucose tolerance test fails to properly suppress GH levels. MRI of the pituitary is used to identify an adenoma or other pituitary abnormalities. Genetic testing may be considered in early-onset cases, particularly for suspected X-LAG.

Treatment aims to normalize GH/IGF-1, control tumor growth, and reduce metabolic risks. Management includes surgical removal of a pituitary tumor when feasible, and adjunctive medical therapy with somatostatin receptor ligands, GH receptor antagonists, or dopamine agonists. Radiotherapy may be used for residual disease. Early and effective treatment improves final height outcomes and lowers complication risks.