Acromegaly - Diagnosis and Management Summary - GrepMed Handbook 



Clinical Presentation: 

 • Classic Acromegaly: frontal bossing, enlarged jaw (macrognathia), ↑ hand + feet size, coarsening facial features, soft tissue swelling and organomegaly

    - c/f ring tightening, ↑ glove & shoe size, ↑ heel-pad thickness, paresthesias (carpal tunnel) and OSA

    - Arthralgias, hypertrophic arthropathy

 • Insidious onset, often undiagnosed for 10+ years. 

    - Usually presents ~5th decade → peripheral/acral enlargement

     - If GH excess occurs before epiphyseal fusion (children) → Gigantism

 • Organomegaly: Visceral organs, macroglossia, goiter, LV hypertrophy, colon (↑polyps & malignancy)

 • Cutaneous: hyperhidrosis, hair growth, skin tags, skin thickening, acanthosis nigricans, cutis verticis gyrata. 

 • Macroadenoma direct effects: Headache (60%), Vision Δs (bitemp hemianopia 10%), HyperPRL (30%), Hypogonad (50%)

 • Metabolic: Insulin resist + DM, Hyperphosphatemia (70%)

 • ↑Mortality due to CVD & colon malignancy



Pathophysiology: 

 • Acromegaly occurs secondary to GH hypersecretion.

 • GH stimulates liver IGF-1 (somatomedin C) secretion. GH + IGF-1 → multisystemic anabolic effects with acromegaly and organomegaly. 

 • ~98% - GH-secreting pituitary adenoma (Up to 30% of pituitary adenomas are mixed GH & PRL) 

 • ~2% - Extrapituitary secretion: pancreatic islet cell tumor, excess GHRH release, central (hypothalamic hamartoma) or peripheral (bronchial/abdominal carcinoid or SCLC).



Differential Diagnosis (Pseudoacromegaly/Acromegaloid): insulin resistance pseudo-acromegaly, obesity, hypothyroidism, pachydermoperiostosis, drugs (phenytoin, minoxidil), genetic (Beckwith Wiedemann syndrome) 



Diagnosis and Workup:

 • Serum IGF-1 level (↑Sens) - GH levels not useful as levels are variable

    - If IGF-1 equivocal: Oral glucose suppression test → ⨁ if failure to suppress GH levels to <1ng/mL. 

 • Pituitary testing: ↑PRL in mixed adenoma, ↓(TFT, LH, FSH & ACTH) 2/2 adenoma mass effect

 • Pituitary MRI+contrast



Management:

 • 1st line - Transsphenoidal surgical resection for adenoma

 • Medical Tx (non-surgical candidates, adjuvant Tx, or post-op residual dz): Somatostatin analogues (Lanreotide) ± GH receptor antagonist (Pegvisomant) ± D2 agonist (Carbergoline)

 • Radiotherapy: Relapse or refractory cases



By Dr. Anuj Thakre (@thakre_anuj)



#Acromegaly #Diagnosis #Management #Endocrinology #Treatment #Pathophysiology