Adrenal incidentaloma by Supphachoke Khemla MD. Supphawatana phaphun MD. 20 March 2552
Dec 23, 2015
Adrenal incidentaloma
bySupphachoke Khemla MD.Supphawatana phaphun
MD.20 March 2552
Cross Sectional Anatomy
• Normal size (Lt or Rt adrenal) : 3 cm × 6 mm
• Retroperitoneum organ• Gerota’s fascia : connect the gland to
upper pole of the kidney
Introduction
• Mass lesion greater than 1 cm.• Serendipitiously discovered by
radiologic examinations• Such as : - Computed tomography (CT) - Magnetic resonance
imaging (MRI)• Two questions - Is it malignancy ? - Is it functioning ?
Prevalence• Autopsy : Total 739 cases (adrenal masses between 2 mm – 4
cm) - 9 % normotensive - 12 % hypertension• The Mayo clinic - 61,054 abdominal CT scans - 1985 – 1990 - adrenal masses : 2,066 cases (3.4%)
Prevalence• The Mayo clinic 2,066 cases : - 50% metastasis cancer - 25% other known lesions - 7.5% symptomatic tumors - 16.5% incidental (include nodules <
1cm) - Overall incidental adrenal tumor (> 1cm) = 0.4 %
Prevalence
• Recent study : high resolution scanner - report prevalence from CT
abdomen = 4.4%• Demonstration : enlarged & unusually
shaped 1. one adrenal mass 2. bilateral adrenal masses
Bilateral masses
• Studies : 887 and 202 cases (with adrenal incidentaloma)
- bilateral 10-15% - causes : - metastasis - pheochromocytoma
- congenital adrenal hyperplasia - amyloidosis - cortical adenoma - infiltrative disease of
adrenal gl. - lymphoma - Infections : TB, fungus - hemorrhage - ACTH-dependent
Cushing’s - ACTH-independent bilateral macronodular adrenal
hyperplasia
Bilateral masses
• One adrenal mass : non-functioning cortical adenoma
• Contralateral adrenal mass : hormone secreting
+++ All patients with bilateral adrenal masses should be screened for adrenocortical hyper/hypo function +++
Evaluate for malignancy
• Primary adrenal carcinoma : quite rare
• Others : - metastasis (particularly lung cancers)• Evaluate : size and imaging
characteristics (imaging phenotype)
Size
• The maximum diameter is predictive of malignancy
• Important : if the smaller is at the time of diagnosis, the better overall prognosis
• Adenocortical carcinomas - significantly asso. with mass size - 90% > 4 cm
Size
• The National Italian Study Groups - 4 cm cutoff - sensitivity 93 % - specificity 76 %
Imaging phenotype
• MRI or CT• 3-5 mm. cuts : predict histological type
of adrenal tumor• Characteristics of the mass example ; lipid-rich nature of cortical
adenomas (benign tumor)
CT scan• Density (black is less dense)• Spectrum : Air -black, Bone-white• Hounfield scale is a semiquantitative method
of measuring x-ray attenuation• Typical precontrast Hounsfield unit (HU)
valves adipose tissue = -20 to – 150 HU kidney = 20 to – 150 HU if adrenal mass < 10 HU on unenhanced CT (ie, has density of fat) likelihood benign adenoma 100 %
CT scan• contrast-enhanced CT - adenoma : rapid contrast medium
washout - non-adenoma : delayed contrast medium
washout • 10 mins after administration pf contrast - adenoma : absolute contrast media
washout > 50 % ( 100% sensitivity & specificity)
if compared with carcinomas, metastasis or pheochromocytoma
CT scan
• Imaging phenotype does not predict hormone function, it can predict underlying pathology, and surgical resection
MRI
• Although CT : primary adrenal imaging• MRI has advantages in certain clinical
situations• Several difference MRI1. - conventional spin-echo MRI - was the first - T1 and T2 - distinguish benign adenomas
from malignancy and
pheochromocytoma
MRI
2- gadolinium-DPTA-enhanced MRI - adenoma : mild enhancement and
rapid washout of contrast - malignancy : rapid and marked enhancement and a slower washout pattern
MRI3 - Chemical shift imaging (CSI) - lipid sensitive imaging - principle : hydrogen protons in water, lipid molecules - chemical shift technique 1. in-phase : water & lipid are aligned : signal intensity high 2. out of phase : opposite from each
other : signal intensity low
MRI
• Interpretation - benign adrenal cortical adenoma :
lose signal on out-of-phase images, but appear relatively bright on in-phase images
Others • PET (Positron emission tomography) - fluoro-2-deoxy-D-glucose (FDG) - high sensitivity for detect malignancy - however : 16% benign cortical lesions
may have FDG-PET uptake - Metomidate (MTO) PET : lack of MTO – specific to non-adrenal cortical origin (metastasis & pheochromocytoma
Others
• PET (Positron emission tomography) - FDG-PET and MTO-PET are not
recommend (cost and insufficiency data to
support their routine use)
Imaging characteristics
Benign adenoma
• Benign cortical adenoma• Round & homogenous density < 4 cm, unilateral• low unenhanced CT
attenuate values (<10HU)• Rapid contrast washout (10
min)• Absolute contrast washout
>50%• Isointensity with liver on both
T-1 & T-2 (MRI)• Chemical shift : lipid on MRI
Pheochromocytoma
• Increase attenuate on nonenhanced CT (>20HU)
• Increase mass vascularity• Delayed contrast
washout (<10 cm)• Absolute contrast
washout <50 %• High signal intensity on T-
2 MRI• Cystic and hemorrhage • Variable size
Pheochromocytoma
Adrenocortical carcinoma• Irregular shape• Inhomogenous density (central
necrosis) > 4 cm, unilateral, calcify• High unenhanced CT (>20HU)• Delayed contrast washout (10
min)• Absolute contrast washout < 50
%• Hypointensity compared with
liver T-1 and high to intermidiateintensity T-2 MRI
• High standard uptake value (SUV) on FDG-PET-CT study
• Evidence of local invasion or metas.
Metastasis
• Irregular, inhomogenous• Bilateral• High enhanced CT (>20 HU)• Enhancement with contrast• Delayed contrast washout (10 min)• Absolute contrast washout < 50%• Isointensity or slightly less intense than liver T-1 ,
high to intermediate intensity T-2 MRI (represent water increase)
Others
• Adrenal cysts• Adrenal hemorrhage• myelolipoma
Fine-needle aspiration biopsy
• Cannot distinguish a benign adrenal mass from the rare adrenal carcinoma
• Thus; FNA biopsy - indicated a suspicion of cancer
outside the adrenal gland - staging evaluation for a known
cancer - not useful routine evaluation
IS IT FUNCTIONAL?
• 6% - 20% of adrenal incidentalomas have hormonal abnormality.
• Hormonal hypersecretion is most likely in mass are at least 3 cm in diameter.
• Occurs mostly within the first 3 years after diagnosis.
85 percent of the masses were non fuctioning.
• 9 percent secreted sufficient cortisol to produce subclinical Cushing's syndrome .
• 4 percent were pheochromocytomas (less than half caused hypertension) .
• 2 percent were aldosteronomas .
• A careful personal and family history, review of systems, PE.
• At minimum for the following condition.– Pheochromocytoma– Cushing syndrome (including subclinical
disease)– Primary aldosteronism (only if
hypertensive)
Pheochromocytoma
• 3-10% of adrenal incidentalomas prove to be pheochromocytomas.
• Screening for pheochromocytoma is mandatory in all case.
• Because high rate morbidity and mortality.
• It is symptomatic up to 15% of case.
• Screening test is measurement of plasma free metanephrines or 24 hr urine metanephrine .
• Plasma free metanephrines is 99% sensitive.
• Not very specific 85-89%
Cushing syndrome
• 5-20% of pt with adrenal incidentaloma are report to have subclinical Cushing syndrome.
• Subclinical Cushing's syndrome– mild hypercortisolism without clinical
manifestations of Cushing's syndrome .
• most frequent hormonal abnormality detected in patients with adrenal incidentalomas .
• In 2002 ,a National institutes of Health consensus panel recommened a 1 mg over night dexamethasone supression test.
• Lack of supression interfering condition.– Decrease dexamethason absorbtion.– Drug : barbiturate, phenyltoin,
carbamazepine, rifampicin.– Increase concentration of corticosteroid-
binding globulin– Pseudo Cushhig state
• Hormonal evaluation in subclinical Cushing's syndrome showed the following– Low baseline secretion of corticotropine
(ACTH) in 79 percent – Lack of suppressibility of cortisol secretion
after 1 mg dexamethasone in 73 percent – Supranormal 24-hour urinary cortisol
excretion in 75 percent
– Disturbed cortisol circadian rhythm in 43 percent
– Blunted plasma ACTH responses to corticotropin-releasing hormone in 55 percent
• If the post-overnight DST
• Then baseline serum ACTH, two-day high-dose DST is indicated to confirm the excess hormone secretion.
Primary Hyperaldosteronism
• 1.6-3.8% of adrenal incidentalomas.• Pt with hypertension should be evaluated
for primary aldosteronism.• Hypokalemia suggest aldosteronism.• Normal K not exclude.• The best screening test is the ratio of the
plasma aldosterone to the plasma renin activity.
Management of adrenal incidentaloma
Clinical and CTapperance
investigation
Treatment
F/U
True cyst
Aspirate?
Repeat CT at 1 yr
adrenolipoma
resect
or
Metastasiscarcinoma
FNAB
Metastasia CA
Resect if appropriate
Diagnosis unclear
Non fuctioning functioning
BPserumK
CatecholamineOvernigth 1 gm DSTUrine 17 OHCS 17KS
FNA < 6 CM > 6CM
Adenal tissue
resect resect
Repeat CT at 2,8,18 mo
• subclinical Cushing's syndrome and unilateral adrenalectomy?
• absence of a prospective randomized study• candidates for adrenalectomy.• who have attributable to excess
glucocorticoid secretion (eg, recent onset of hypertension, diabetes, obesity, and low bone mass)
• lack of suppression to both an overnight DST) and a two-day high-dose DST.
Bilateral adrenal masses
• The management of bilateral adrenal masses is different from that for unilateral masses.
SUMMARY
• All patients should be evaluated for subclinical hormonal hyperfunction and cancer.
• History and physical examination are important in the initial assessment.
Benign cortical adenoma. A homogeneous adrenal mass <4 cm in
diameter, with a smooth border, and an attenuation value <10 HU on
unenhanced CT, and rapid contrast medium washout (eg,
>50 percent at 10 minutes)
The imaging suggest adrenal carcinoma or metastases include: irregular shape. inhomogeneous density. high unenhanced CT attenuation values
(>20 HU), delayed contrast medium washout (eg, <50 percent at 10 minutes),
diameter >4 cm, and tumor calcification. Other characteristics are described above.
• Pheochromocytoma should be excluded by measuring 24-hour urinary fractionated metanephrines and catecholamines.
• Subclinical Cushing's syndrome should be ruled out by the 1-mg overnight dexamethasone.
• primary aldosteronism. should be screen in patient is hypertensive by a plasma aldosterone-to-plasma renin activity ratio and plasma potassium concentration
• Recommend surgery: pheochromocytoma, aldosteronoma.
• Suggest surgery for patients with subclinical Cushing's syndrome who are younger and who have disorders potentially attributable to autonomous glucocorticoid secretion.
• Suggest surgery for patients with adrenal masses greater than 4 cm in diameter .
• If there is evidence of metastasis and after excluding pheochromocytoma with biochemical testing, suggest performing a diagnostic CT-guided FNA biopsy .
THANK YOU