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Adrenal Incidentaloma: Evidence Based Approach. Dr Daniel Wong Department of Surgery Kwong Wah Hospital. Adrenal Incidentaloma- Definition. Adrenal mass >1cm Detected during investigation for extra-adrenal pathology Exclude workup of Known malignancy patients
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Adrenal Incidentaloma:Evidence Based Approach Dr Daniel Wong Department of Surgery Kwong Wah Hospital
Adrenal Incidentaloma- Definition • Adrenal mass >1cm • Detected during investigation for extra-adrenal pathology • Exclude workup of • Known malignancy patients • Hypertensive and hypokalaemic patients
Adrenal Incidentaloma- Definition • Prevalence 1.4-8.7% • Found in up to 5% CT scan Angeli Horm Res 1997 Barzon et al Eur J Endocrinol 2003
Adrenal Incidentaloma- Aetiology • Adrenal cortical tumours • Adenoma, nodular hyperplasia, carcinoma • Adrenal medullary tumours • Pheochromocytoma • Rare tumours • Lipoma, myelolipoma • Metastatic lesion • Others- cyst, abscess, haematoma
Adrenal Incidentaloma- Aetiology • Risk of malignancy & functional tumours overestimated Cawood et al Eur J Endocrinol 2009
Adrenal Incidentaloma- Natural History • Most are non functional adenoma • Size of lesion crucial • >25% malignant if >6cm • 2% malignant if <4cm • 20% develop subsequent hormone production • 25% may increase in size NIH State of the Science guidelines 2002
Management Guidelines • National Institute of Health State of the Science guidelines 2002 • Young NEJM 2007 guidelines • Singh et al ACP best practice guidelines • J Clin Pathol 2008
Adrenal Incidentaloma Workup • Whether it is functional • Blood pressure, potassium (not reliable) • Aldosterone/renin ratio • 1mg overnight dexamethasone suppression test • 24 hour urine metanephrine, catecholamines • Plasma DHEAS level (optional) NIH State of the Science Guidelines 2002
Adrenal Incidentaloma Workup • Whether it is malignant: CT scan findings • >6cm high chance of malignancy • Ideal lower cut off controversial • 4cm cutoff- 90% sensitivity for cancer • 76% of lesion excised were benign • Smooth, sharp border, calcifications Angeli Hormone Res 1998 NIH State of the Science Guidelines 2002 Yong NEJM 2007
Adrenal Incidentaloma Workup • Whether it is malignant: CT scan findings • Adenoma has higher fat content • Density (Hounsfield Unit): <10 likely adenoma • Enhancement washout >50% at 15 minutes likely adenoma NIH State of the Science Guidelines 2002
Adrenal Metastasis Adrenal Carcinoma Adapted from Dunnick AJR 2002
2.8x2.8x2.3cm pheochromocytoma 9x8x8cm benign adenoma Linos Hormone 2003
Adrenal Incidentaloma Workup • CT guided biopsy • Only recommended if known primary cancer • i.e. not true incidentaloma • Need to exclude phaeochromocytoma first! • Random use give low diagnostic yield
Yield of CT Guided Biopsy Mazzaglia Arch Surg 2009
Adrenal Incidentaloma Workup • MRI • No proven benefit over CT scan • Role of PET scan • Only if known history of carcinoma • 100% sensitivity in detecting metastasis Frilling et al Surgery 2004
Management- Surgery • If hormonal active or suspicious CT scan • Laparoscopic approach recommended • Crucial to consider the indication of surgery Conzo Can J Surg 2009
Management- Follow up • CT scan at regular intervals • 6/12/24 months • Annual hormonal workup • Discharge if static for 4 years NIH State of the Science Guidelines 2002
Subclinical Cushing’s Syndrome • Subclinical Cushing’s Syndrome (SCS) • Mild secretion of cortisol without clinically evident signs of hormone excess • No universally accepted definition Rossi J Clin Endocrinol Metab 2000
Subclinical Cushing’s Syndrome • 5-20 % AI patients • Large percentage with hyperlipidaemia, hypertension, diabetes • Risk of cardiovascular diseases • Lower bone density, increased fracture risk • Surgery improves diabetic, BP control, lipid profile and obesity Comlekci et al Endocrine 2009 Chiodini J Clin Endocrinol Metab 2009 Toniato Ann Surg 2009
Conclusions • AI - common radiological finding • Most are benign and indolent • Size good predictor of malignant risk • Regular follow up needed • Expanding indications for surgery in laparoscopic era