Clinical Guideline
SUSPECTED ADRENAL ‘INCIDENTALOMA’
SETTING
Trust-wide
FOR STAFF
Part 1 - Medical staff, including radiologists, who identify a possible case
Part 2 – Specialist medical staff within Endocrine Team
PATIENTS
Patients with an unexpected adrenal lesion following diagnostic imaging
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BACKGROUND
‘Incidentaloma’ is an internationally accepted term for a lesion incidentally discovered through
diagnostic imaging, without prior clinical suspicion of tumour / disease.
Published evidence (1,2) suggest the following pathology for adrenal incidentalomas;


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


Endocrine inactive adenoma
Metastases
Cortisol secreting adenoma
Adrenocortical carcinoma
Phaeochromocytoma
Conn’s
Other causes
41 - 85% of cases
‘’
15 - 19%
‘’
5 - 10%
%
‘’
2 - 10
‘’
3 - 8%
‘’
2 - 5%
%
‘’
2- 9
Part 1
REFERRAL TO ENDOCRINE TEAM
Medical staff that identify a possible adrenal incidentaloma should refer the patient to
the Endocrine Team for further investigation.
Referral details should include


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Hospital Registration Number
Surname
Forname
Date of Birth
Date of diagnostic imaging
Imaging report number
Part 2
ENDOCRINE TEAM ONLY (overleaf)
Version 1 Sept 2011 - Review Sept 2014
Author Dr Karin Bradley, Endocrinology Consultant
Page 1 of 3
Part 2
ENDOCRINE TEAM ONLY
The algorithm below describes the diagnostic pathway
There are no long term data to be confident of the appropriate duration of imaging or hormonal surveillance but
abnormal secretion has been detected during prolonged follow-up 3,4,5. The risk of endocrine abnormalities was
higher in patients with a baseline lesion ≥ 3cm. This guideline is consistent with recent clinical practice
guidelines1,6,7,8.
ASSESSMENT OF ENDOCRINE STATUS
Careful personal and family history and full examination
Proceed as appropriate if underlying endocrinopathy suspected
RECOMMENDED OUT-PATIENT TESTS IF NO ENDOCRINE PHENOTYPE SUSPECTED
1.
2.
3.
Two 24 hour urine collection samples for catecholamines (N.B. regional laboratories may use alternative baseline screening
tests) to help exclude phaeochromocytoma#. Ideally avoid interfering medication including paracetamol, many
antihypertensives, catecholamine containing drugs & some antidepressants). Plasma metanephrines may be indicated,
especially in the context of a genetic phaeo/paraganglioma syndrome.
1mg overnight dexamethasone suppression test to exclude subclinical Cushing's (*see below). (1mg dexamethasone at
11PM followed by serum cortisol at 9 am next morning. The morning cortisol should ideally be <50nmol/l. Values 50nmol/l138nmol/l fall into an area of clinical uncertainty and surgery may be discussed as an option especially in the presence of
diabetes or hypertension. In the absence of any classic phenotype further Cushing’s investigations probably only helpful if
overnight result >138nmol/l or clinical progression9. However, UFC (urinary free cortisol), low dose dexamethasone
suppression test, morning ACTH or midnight salivary cortisol may be considered.
Aldosterone/Renin ratio (ARR) only in hypertensive patients to exclude Conn's syndrome. Aldosterone and renin levels are
affected by many anti-hypertensive agents. Ideally use doxasozin alone for 4-6 weeks pre-testing. Correct potassium to
normal pre test. If ARR sufficiently elevated (refer to local laboratory range) then proceed to a confirmatory test e.g. saline
infusion or fludrocortisone suppression and adrenal CT. Adrenal vein sampling should be considered unless patient <40years
with clear unilateral >1cm adenoma10.
BIOCHEMICALLY FUNCTIONING
(Include subclinical Cushing’s in this
category but remember that surgery for
this indication remains controversial.
BIOCHEMICALLY NON-FUNCTIONING
Consider presence of diabetes,
hypertension or other CV risk and patient
choice when counselling)
Less than 4cm in size
Baseline malignancy risk ~ 2%
Hounsfield
units less
than 10,
benign
appearance
on CT & no
personal
history of
malignancy
1.
2.
3.
4.
4cm or greater in size
Baseline malignancy risk
Size 4-6cm ~ 6% risk6, Size >6cm ~ 25% risk6
Hounsfield units more
than 10 (? fat poor
benign adenoma in 25
% cases) or history of
malignancy11,12
Repeat CT scan 6 months after
baseline scan and calculate
contrast washout at 10 minutes.
Consider MRI in women of
reproductive age or where there
is impaired renal function or
known contrast sensitivity
No repeat imaging required2.
Hormonal surveillance at baseline and at 2 years.
Hormonal surveillance at 4 years if baseline size ≥
3 cm3. Up to 20% will become hormonally active2.
Consider surgery if mass becomes hormonally
active.
When discharging to GP care recommend referral
for re-evaluation if symptoms dictate as rarely
functional activity has been described after
prolonged follow-up.
Version 1 Sept 2011 - Review Sept 2014
Consider surgery. Refer to
neuroendocrine tumour (NET)
MDT. Remember the need for
peri- and post-operative steroids
if evidence of endogenous
hypercortisolaemia. Postoperatively ensure resolution of
any abnormal biochemistry.
If adrenal carcinoma suspected
measure testosterone, DHEA,
17OHP & androstenedione and CT
chest. FDG-PET can be a useful
tool for identifying adrenal
malignancy.
Contrast washout
greater than 60%
in 10 minutes3 –
likely fat poor
benign adenoma
Contrast washout less than 60% at 10
minutes3 or an increase in size >1cm.
Author Dr Karin Bradley, Endocrinology Consultant
Page 2 of 3
#It
is worth noting that a phaeochromocytoma is extremely unlikely if Hounsfield units are less than 10. A phaeochromocytoma
diagnosis becomes more likely if the Hounsfield units are more than 10 and the lesion is more than 3cm in size.
*Various medications may interfere with dexamethasone metabolism and this should be taken into account when interpreting the
overnight dexamethasone suppression test. These include sertraline, fluoxetine, paroxetine, trazodone, citalopram, bupropion,
venlafaxine, atorvastatin, simvastatin, verapamil, diltiazem, amlodipine, nifedipine, felodipine, irbesartan, losartan, olanzapine,
quetiapine, proton pump inhibitors, propranolol, pioglitazone, clonazepam and topiramate13.
_________________________________________________________________________
REFERENCES
1. National Institute of Health consensus statement. Management of the Clinically
Inapparent Adrenal Mass 2002. Volume 19 (2)
2. Mansmann G, Lau J, Balk E, Rothberg M, Miyachi Y & Bornstein SR. The Clinically
Inapparent Adrenal Mass: Update in Diagnosis and Management. Endocrine Reviews
25(2):309–340.
3. Barzon L et al. Development of overt Cushing’s syndrome in patients with adrenal
incidentaloma. European Journal of Endocrinology (2002) 146 61–66
4. Funder JW, Carey RM, Fardella C, Gomez-Sanchez CE, Mantero F, Stowasser M, Young
WF, Jr, Montori VM, Endocrine Society 2008 Case detection, diagnosis, and treatment of
patients with primary aldosteronism: An endocrine society clinical practice guideline. J
Clin Endocrinol Metab 93(9):3266-3281.
5. AACE/AAES Medical Guidelines for the Management of Adrenal Incidentalomas .
Endocrine practice 2009; 15 (Suppl 1)
6. Hamrahian H et al. Clinical utility of non contrast computed tomography attenuation value
(hounsfield units) to differentiate adrenal adenomas/hyperplasias from nonadenomas:
Cleveland Clinic experience. J Clin Endocrinol Metab 2005; 90(2):871-7.
7. Szolar D et al. Adrenocortical Carcinomas and Adrenal Pheochromocytomas: Mass and
Enhancement Loss Evaluation at Delayed Contrast-enhanced CT. Radiology 2005: 234
(2). 479-485
8. Barzon et al. Risk factors and long-term follow-up of adrenal incidentalomas. J. Clin.
Endocrinol. Metab. 1999 84: 520-526
9. Libe et al. Long-term follow-up study of patients with adrenal incidentalomas. European
Journal of Endocrinology (2002) 147 489–494
10. Bulow B et al. Adrenal incidentaloma – follow-up results from a Swedish prospective
study. European Journal of Endocrinology (2006) 154 419–423
11. Gopan T et al. Evaluating and managing adrenal incidentalomas. Cleve Clin J Med. 2006
Jun;73(6):561-8
12. Young W. The Incidentally Discovered Adrenal Mass. N Engl J Med 2007;356:601-10
13. Valassi E et al. Concomitant medication use can confound interpretation of the combined
dexamethasone-corticotropin releasing hormone test in Cushing’s syndrome. JCEM
2009; 94: 4851-9.
QUERIES
Endocrine Specialist Registrar (referrals)
bleep 6216
Endocrine Consultants
Dr K Bradley,
Dr B Ahmad
Dr N Thorogood
Prof S Lightman
Prof A Levy
Prof D Wynick
via switchboard
Version 1 Sept 2011 - Review Sept 2014
Author Dr Karin Bradley, Endocrinology Consultant
Page 3 of 3