1. Adrenal Incidentaloma: Evidence Based Approach
Dr Daniel Wong
Department of Surgery
Kwong Wah Hospital

2. Adrenal Incidentaloma- Definition
Adrenal mass >1cm
Detected during investigation for extra-adrenal pathology
Exclude workup of
Known malignancy patients
Hypertensive and hypokalaemic patients

3. Adrenal Incidentaloma- Definition
Prevalence %
Found in up to 5% CT scan
Angeli Horm Res 1997
Barzon et al Eur J Endocrinol 2003

4. Adrenal Incidentaloma- Aetiology
Adrenal cortical tumours
Adenoma, nodular hyperplasia, carcinoma
Adrenal medullary tumours
Pheochromocytoma
Rare tumours
Lipoma, myelolipoma
Metastatic lesion
Others- cyst, abscess, haematoma

5. Adrenal Incidentaloma- Aetiology
Risk 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%
Ca half of quoted, phaeo 2/3, conn’s half by excluding surgical series
Cawood et al Eur J Endocrinol 2009

6. 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

7. 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

8. 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

9. 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

10. 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

11. Adapted from Dunnick AJR 2002
Adrenal Metastasis
Adrenal Carcinoma
Adapted from Dunnick AJR 2002

12. 2.8x2.8x2.3cm pheochromocytoma
9x8x8cm benign adenoma
Linos Hormone 2003

13. 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

14. Yield of CT Guided Biopsy
Mazzaglia Arch Surg 2009

15. 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
81% if CT only
Frilling et al Surgery 2004

16. Nonfunctioning adenomas
Management- Surgery
If hormonal active or suspicious CT scan
Laparoscopic approach recommended
Crucial to consider the indication of surgery
Surgical 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

17. NIH State of the Science Guidelines 2002
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

18. Subclinical Cushing’s Syndrome
Subclinical Cushing’s Syndrome (SCS)
Mild secretion of cortisol without clinically evident signs of hormone excess
No universally accepted definition
At least 2 HPA axis functional parameters
Rossi J Clin Endocrinol Metab 2000

19. 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
376 AI patients
The overall prevalence of Type 2 diabetes mellitus, hypertension, hyperlipidemia, and metabolic syndrome was 18.4, 54.9, 59.6, and 48.1%, respectively.
Comlekci et al Endocrine 2009
Chiodini J Clin Endocrinol Metab 2009
Toniato Ann Surg 2009

20. 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