Related Subjects:
|Male Infertility
|Prolactin
|Prolactinoma
|Sheehan's syndrome
|Acromegaly and Giantism
𧬠It is important to measure serum IGF-1 to rule out acromegaly β
and not rely on random GH levels (which fluctuate and are unreliable).
π About
- π¨ββοΈ Pituitary tumour (somatotroph adenoma) β usually requires surgery
- π Gigantism: GH excess before epiphyseal fusion (adolescents)
- π§ Acromegaly: GH excess in adults, usually 20β40 yrs
π§ͺ Aetiology
- βοΈ Pituitary somatotroph adenomas (often βacidophilβ macroadenomas)
- 𧬠Sometimes due to G-protein mutations
π©Ί Clinical Features
- π Hypertension, π¦ sweating, offensive odour
- π Enlarged nose, π¦· interdental spacing
- π Spade-like hands, βοΈ thickened skin, hats/rings donβt fit
- 𦴠Prominent supraorbital ridges, frontal sinus enlargement
- π¬ Prognathism (enlarged jaw)
- π« Organomegaly: liver, heart, tongue, lips, hands/feet (β heel pad)
- π§ Pituitary tumour mass effect (headache, visual field loss)
- π Hyperglycaemia, T2DM, myopathy
- π« Carpal tunnel syndrome
- π Colonic cancer risk ~5% if >50 yrs, >10 yrs disease, β₯3 skin tags
π€ Associated Conditions
- π΄ Sleep apnoea
- π Type 2 diabetes
- 𦴠Debilitating arthritis
- β Carpal tunnel syndrome
- π¦ Hyperhidrosis
- π Hypertension
π Investigations
- π§ͺ Basic bloods: FBC, U&E, LFTs, glucose, HbA1c
- π Screening: β Serum IGF-1 (3β10Γ) β first test, stable levels, monitor therapy
- β
Diagnostic: GH suppression test β 75 g glucose should β GH < 0.4 mcg/L within 1β2h (failure = acromegaly)
- π§ Pituitary MRI + gadolinium β macroadenoma in 90%, bony changes (enlarged sella, thickened skull)
- ποΈ Formal perimetry if tumour abuts optic chiasm
- π Hormone screen: PRL, TFTs, FSH/LH, cortisol, testosterone/estradiol
- πΊ CT brain if MRI contraindicated
- π Colonoscopy (β risk of colonic neoplasia)
- β€οΈ BNP, ECG, echocardiogram (exclude cardiomyopathy/heart failure)
π§Ύ Differential Diagnosis
- GH-secreting pituitary tumour
- Mixed GH/PRL pituitary adenoma
- GH/GHRH-secreting neuroendocrine tumour (e.g., pancreatic islet)
- βAcromegaloidismβ in severe insulin resistance
π Management
- π― Target: age-normalised IGF-1 + random GH < 1.0 mcg/L
- πͺ Surgery: Trans-sphenoidal resection = 1st-line (repeatable). Transfrontal only for massive tumours
- β’οΈ Radiotherapy: used post-surgery; risks = hypopituitarism, cranial nerve damage, secondary tumours
- π Medical therapy:
- Somatostatin receptor ligands (octreotide, lanreotide) β β GH, shrink tumour (50% cases)
- Dopamine agonist (cabergoline)
- GH receptor antagonist (pegvisomant) β β IGF-1, adjunctive
- Often combined for efficacy + β side effects
- π§© Pituitary hormone replacement as needed (thyroxine, hydrocortisone, sex hormones)
- π Repeat MRI every 3β6 months post-treatment
π References