Introduction
Acromegaly and gigantism are hormonal disorders caused by excessive growth hormone secretion usually due to a pituitary tumor
-Acromegaly develops if excessive GH exposure occurs after closure of the long bone epiphyses (Adults = Acromegaly); where as gigantism develops if it occurs before closure of the epiphyses
-Grown hormone hypersecretion leads to excessive generation of IGF-1, which acts as the mediator of most of the effects of GH
-The average age at the time of diagnosis is 40 to 45 years
Symptoms & Signs
Facial Features: Frontal bossing, macroglossia, Jaw enlargement (prognathism), widened teeth spacing
Musculoskeletal features: Increased hat, shoe, glove and ring size; Enlargement of hands and feet with a doughy texture; arthropathy, carpal tunnel syndrome, kyphoscoliosis
ENT: Large fleshy nose, deepening of the voice, snoring
Skin: Doughy texture, cutis verticis gyrata, acanthosis nigricans, skin tags, thick heel pads, hyperhidrosis, hirsutism
Eyes: Bitemporal hemianopsia (due to optic chiasm compression from the tumor)
Associated conditions: Diabetes, hypertension, glucose intolerance, cardiomyopathy, left ventricular hypertrophy, diastolic dysfunction
Diagnosis
Insulin-like growth factor – 1 : Elevated levels
Growth hormone: Elevated levels in serial measurements; Failure to suppress Growth hormone levels by oral glucose-tolerance test
Imaging: MRI of the pituitary may show macroadenoma
Treatment
Surgery: Removal of adenoma by transsphenoidal surgery
Somatostatin analogues: Octreotide, lanreotide, pasireotide
Dopamine agonists: Bromocriptine, cabergoline
GH receptor antagonist: Pegvisomant
Radiation: Pituitary irradiation
Q. What is the most important requirement for diagnosis of GH excess? Demonstration of unsuppressable GH secretion