Dr Daniel WongDepartment of SurgeryKwong Wah Hospital

Adrenal Incidentaloma- DefinitionAdrenal mass >1cm Detected during investigation for extra-

adrenal pathologyExclude workup of

Known malignancy patientsHypertensive and hypokalaemic

patients

Adrenal Incidentaloma- Definition

Prevalence 1.4-8.7%Found in up to 5% CT

scan

Angeli Horm Res 1997Barzon et al Eur J Endocrinol 2003

Adrenal Incidentaloma- AetiologyAdrenal cortical tumours

Adenoma, nodular hyperplasia, carcinoma

Adrenal medullary tumoursPheochromocytoma

Rare tumours Lipoma, myelolipoma

Metastatic lesionOthers- cyst, abscess, haematoma

Adrenal Incidentaloma- AetiologyRisk of malignancy & functional tumours

overestimated

Condition Prevalence

Adrenal cancer 1.9%

Metastasis 0.7%

Phaeochromocytoma 3.1%

Conn’s syndrome 0.6%

Subclinical Cushing’s Syndrome

6.4%

Cawood et al Eur J Endocrinol 2009

Adrenal Incidentaloma- Natural History

Most are non functional adenoma Size of lesion crucial

>25% malignant if >6cm2% malignant if <4cm

20% develop subsequent hormone production

25% may increase in size

NIH State of the Science guidelines 2002

Management GuidelinesNational Institute of Health State of the

Science guidelines 2002Young NEJM 2007 guidelinesSingh et al ACP best practice guidelines

J Clin Pathol 2008

Adrenal Incidentaloma WorkupWhether it is functional

Blood pressure, potassium (not reliable)Aldosterone/renin ratio1mg overnight dexamethasone

suppression test24 hour urine metanephrine,

catecholaminesPlasma DHEAS level (optional)

NIH State of the Science Guidelines 2002

Adrenal Incidentaloma WorkupWhether it is malignant: CT scan findings

>6cm high chance of malignancyIdeal lower cut off controversial4cm cutoff- 90% sensitivity for cancer

76% of lesion excised were benignSmooth, sharp border, calcifications

Angeli Hormone Res 1998NIH State of the Science

Guidelines 2002Yong NEJM 2007

Adrenal Incidentaloma Workup

Whether it is malignant: CT scan findingsAdenoma has higher fat contentDensity (Hounsfield Unit): <10 likely

adenomaEnhancement washout >50% at 15

minutes likely adenoma

NIH State of the Science Guidelines 2002

Adapted from Dunnick AJR 2002

Adrenal Metastasis

Adrenal Carcinoma

Linos Hormone 2003

9x8x8cm benign adenoma

2.8x2.8x2.3cm pheochromocytoma

Adrenal Incidentaloma Workup

CT guided biopsyOnly recommended if known primary

canceri.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 WorkupMRI

No proven benefit over CT scanRole of PET scan

Only if known history of carcinoma100% sensitivity in detecting metastasis

Frilling et al Surgery 2004

Management- SurgeryIf hormonal active or suspicious CT scanLaparoscopic approach recommendedCrucial to consider the indication of

surgerySurgical Unit

Nonfunctioning adenomas

Secreting adenomas

Others Total

Endocrine 18 (29.0) 41 (66.1) 3 (4.8) 62

General 95 (50.5) 54 (28.7) 39 (20.7) 188

Conzo Can J Surg 2009

Management- Follow upCT scan at regular intervals

6/12/24 monthsAnnual hormonal workupDischarge if static for 4 years

NIH State of the Science Guidelines 2002

Subclinical Cushing’s SyndromeSubclinical 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 diseasesLower bone density, increased fracture

riskSurgery improves diabetic, BP control,

lipid profile and obesityComlekci et al Endocrine 2009

Chiodini J Clin Endocrinol Metab 2009

Toniato Ann Surg 2009

ConclusionsAI - common radiological findingMost are benign and indolentSize good predictor of malignant riskRegular follow up neededExpanding indications for surgery in

laparoscopic era