Transcript Adrenal incidentaloma

Adrenal incidentaloma
by
Supphachoke 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 MRI
1. - 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
MRI
3 - 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 corticosteroidbinding 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 highdose 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 CT
apperance
True cyst
adrenolipoma
Metastasis
carcinoma
FNAB
investigation
Metastasia CA
Treatment
Aspirate?
resect
or
F/U
Repeat CT at 1 yr
Resect if
appropriate
Diagnosis
unclear
BP
serumK
Catecholamine
Overnigth 1 gm DST
Urine 17 OHCS 17KS
Non fuctioning
FNA < 6 CM
functioning
> 6CM
Adenal tissue
resect
Repeat CT at 2,8,18 mo
resect
• 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