Etiology: excess growth hormone ← eosinophilic adenoma / hyperplasia in anterior pituitary

• gigantism in children: advanced bone age + excessive height (DDx: Sotos syndrome of cerebral gigantism = large skull, mental retardation, cerebral atrophy, advanced bone age)

• osseous enlargement (phalangeal tufts, vertebrae)
• flared ends of long bone
• cystic changes in carpals, femoral trochanters
• osteoporosis

• Hand
  • spadelike hand
  • widening of terminal tufts
• Skull
  • prognathism (= elongation of mandible) in few cases
  • sellar enlargement + erosion
  • enlargement of paranasal sinuses: large frontal sinuses (75%)
  • calvarial hyperostosis: especially inner table
  • enlarged occipital protuberance
• Vertebrae
  • posterior scalloping in 30% ← pressure of enlarged soft tissue
  • anterior new bone
  • loss of disk space (weakening of cartilage)
• Soft tissue
  • heel pad >25 mm
• Joints
  • premature osteoarthritis (commonly knees)