Adrenal gland Incidentaloma

Transcription

1 Adrenal gland Incidentaloma Topic review 17 sep 2008 Anatomy 1

2 Anatomical consideration Blood supply Artery: small branches from Inf. phrenic, renal artery and aorta Vein: Rt : medial aspect to IVC Lt : inferomedial aspect to Lt renal vein Retroperitoneal organs, suprarenal spaces 2

3 Histophysiology Adrenal Cortex : Steroidogenesis Zona glomerulosa: Mineralocorticoid (Aldosterone) Zona fasiculata: Glucocorticoid (Cortisol) Zona reticularis: Adrenal androgens / sex steroid Adrenal medulla : Epinephrine Norepinephrine Dopamine Renin-Angiotensin Angiotensin-AldosteroneAldosterone Pathway 3

4 Glucocorticoids Diurnal variation Peak : Morning Lowest : evening Negative feedback control Sex hormone 24 h urine Testosterone,D HEA, DHEA-S 4

5 Adrenal medulla hormones Epinephrine : 80% Norepinephrine : 20% Dopamine Diagnostic hormonal test Plasma aldosterone concentration/plasma renin activity ratio 24-h urinary cortisol, catecholamine, vanillylmandelic acid excretion Serum potassium 1 mg dexamethasone suppression test Plasma-free metanephrines level 5

6 Imaging in Adrenal mass U/S CT scan MRI PET scan Radionuclide scan Ultrasonography Detect adrenal mass larger than 2 cm. Less sensitive than CT and MRI Useful in children 6

7 CT scan Require narrow collimation 3-5 mm Densitometry HU Cortical adenoma is lipid rich structure If Hounsfield unit of mass in plane CT is less than 0 (fat = -20 to -150), almost 100% is adenoma Contrast study : assess vascularity and distinguish adrenal gland from adjacent vessel CT scan Contrast washout in adenomas is more rapid than nonadenomas. For adenomas; 5 min = 51% 15 min= 70% For nonadenomas; 5 min = 8% 15 min = 20% Both sensitivity and specificity = 96% Mass size in CT is 20% less than actual size. 7

8 MRI CT & MRI have the same sensitivity and specificity Avoid radiation MRI has more advantage that it can separate adenoma, carcinoma, and pheochromocytoma Compare density adrenal mass/liver in T2- weighted pheochromocytoma >3 malignant tumor 1.4 Adenoma

9 Radionuclide scintigraphy Adrenocortisol marker 131 I-6--iodomethyl-norcholesterol (NP-59) and 75 Se-selenomethyl-19-norcholesterol Adrenomedullary marker 123 Imetaiodobenzylguanidine (MIBG) 9

10 Radionuclide scintigraphy PET scan Accumulation of tracer result from increased in glucose metabolism of malignant tumor Sensitivity 100%, specificity 96% Excellent accuracy in proven malignancy Whole body study : extra-adrenal malignancy 10

11 PET scan FNA biopsy Cannot distinguish adrenal adenoma from carcinoma Differentiate adrenal vs non-adrenal tissue (metastatic or infection) Preserved for suspected metastasis disease Under CT guidance Pheochromocytoma to be ruled out before FNA 11

12 Incidentaloma Mass is detected during abdominal imaging done for non-adrenal related reasons Size = 1 cm Incidentally found in imaging No clinically hormonal excess Prevalence In autopsies : Variation 5.9% (range, 1.1% to 32.0% )* 1.4%-9% ** 2.1%*** By CT % in all CT scan * William F. Young Jr MD Endocrinology and Metabolism Clinics Volume 29, Number 1, March 2000 ** L. Michael Brunt, M.D., Jeffrey F. Moley, M.D. World J. Surg. 25, , 2001 *** NIH conference 12

13 Incidence increasing with age In autopsy pt >50 yrs. 3% Prevalence rises to >4% in pt >60 yrs Risk of malignancy <2% in < 4 cm 6% in 4 6 cm >25% in > 6 cm Figure 3. Age-dependent occurrence of adrenal cortical adenomas from six autopsy studies with a total of 57,262 subjects. Although the criteria used to define a nodule in the 6 studies varied, all but 3 nodules were grossly visible and averaged 1 cm in diameter (range, cm). Adrenal cortical nodularity appears to be a consequence of aging 13

14 Size does matter? Evaluation Principle History and Physical exam Hormonal evaluation Functioning adrenal tumor Non functioning adrenal tumor Assessment malignancy potential Management 14

15 Adrenal incidentaloma Adrenal incidentaloma 24 hr metanephrines & catecholamine Low dose (1mg) dexamethasone Suppression test PAC/PRA if HT Functioning Adrenal tumors? Yes No Imaging : CT/MRI Surgery No Suspected malignancy Yes <4 cm Tumor size 4-6 cm F/U: 1ximaging after 6-12 mo Endocrine evaluation 1/yr for 4 yrs >6 cm Search for extra adrenal primary CA Consider percutaneous BX Surgery DDX :Function Benign functioning mass Cortisol-producing adenoma Aldosteronoma Pheochromocytoma Musculinizing or feminizing tumors Malignant functioning mass Adrenocortisol cancer Malignant pheochromocytoma 15

16 DDx: : Non-function Benign non-functioning mass Adenoma Cyst Myelolipoma Hematoma / hemorrhage Ganglioneuroma Cortical cyst Malignant non functioning mass Adrenocortisol carcinoma Metastasis Angiosarcoma Ganglioneuroblastoma Leiomyosarcoma Malignant schwannoma Primary malignant melanoma PREVALENCE OF ADRENAL INCIDENTALOMAS IN DIFFERENT SERIES Type of Tumor Prevalence (%) Matero et al. AI- SIE* Others Nonhypersecretory adrenal adenomas Hypersecretory tumors Cortisol-secreting adenomas Aldosteronomas Pheochromocytomas Adrenal carcinomas Other adrenal masses Myelolipomas Cysts Ganglioneuromas Metastases Unselected patients Oncological patients

17 Functioning mass Aldosteronoma Primary hyperaldosteronism cause of secondary HT. most common 70% - 80% aldosterone-producing adenoma 20%-30% bilateral cortical hyperplasia 1% Aldosterone-producing carcinomas 0-2% of incidentaloma Tumors averaging 1-2 cm in size 17

18 Aldosteronoma Characterized by HT & hypokalemia. Muscle cramps, weakness, or paresthesias. Typically moderate to severe HT refractory to medical Tx. Up to 20% : non-hypokalemic ( restricted salt) Diagnosis: Biological Dx Localization Mx 18

19 Aldosteronoma Hormonal evaluation: Discontinuation of interfering medications: Spironolactone: 6 wks ACE inhibitors Diuretics: 4 wks β-adrenergic blockers PAC/PRA ratio > 30 Suggestive of primary hyperaldosteronism 24-hour urinary aldosterone secretion after saline loading or a high sodium diet Aldosteronoma Localization : CT/ MRI Equivocal Adrenal vein sampling > a 5 fold elevation of cortisol in an adrenal vein /peripheral blood Lateralization of aldosterone to cortisol in adrenal veins (> 4 fold): Aldosteronoma Nonlateralization: Bilateral adrenal hyperplasia NP59 (if inconclusive on either CT or adrenal venous sampling) 19

20 Aldosteronoma Treatment: Aldosteronoma prefer Lap adrenalectomy Bilateral adrenal hyperplasia Medical Rx Preoperative preparation: Cushing s s Syndrome Wt gain, HT, bruisability, DM, obesity Most common: Drug(Glucocorticoids) Endogenous cause is rare: Pituitary adenoma (75%) Adrenal cushing's syndrome (15%) Ectopic ACTH (<10%) Asymptomatic: Subclinical Cushing s syndrome 2 15% of incidentaloma 20

21 Cushing s Syndrome Hormonal evaluation: 24 hour urine free cortisol level Low dose (1mg) Dexamethasone suppression testing <5 mcg/dl : negative >10 mcg/dl :suggestive of Cushing s syndrome 5-10 mcg/dl :equivocal, seen in SAGH Late evening (bedtime) cortisol measurement < 550ng/dL : unlikely Cushing syndrome > 550ng/dL : probable Cushing syndrome 21

22 Cushing s s Syndrome ACTH level ACTH : Adrenal ACTH : Pituitary ( Cushing s disease ) or Ectopic ACTH producing tumor High-dose Dexamethasone suppression testing Suppression : Pituitary lack of suppression: Ectopic ACTH producing tumor Cushing s s Syndrome Bilateral petrosal venous sampling for ACTH gradient Equivocal +ve ACTH gradient : Pituitary Localization : CT, MRI Treatment : Adrenal Adrenalectomy recommended for younger patients (<40 yrs old) Autonomous glucocorticoid secretion (e.g., the recent onset/worsening of underlying HT, DM, obesity, or osteoporosis) 22

23 Cushing s s Syndrome Pituitary Ectopic Transphenoidal resection Treat primary Perioperative stress dose steroids (hydrocortisone,100 mg IV every 8 hrs for 24 hrs) Pheochromocytoma A catecholamine producing tumor Occasionally clinical silence 0-11% of incidentaloma Classic triad: Headache Diaphoresis Palpitations 10% tumor: bilateral, malignant, extra-adrenal, & familial. 23

24 Pheochromocytoma Hormonal evaluation: Plasma free metanephrine 24hrs urine metanephrines & catecholamines Clonidine suppression testing Localization : CT/ MRI, MIBG 24

25 Pheochromocytoma Preoperative care: Alpha adrenergic blocker + forced hydration for at least 7-10 days Beta-adrenergic blocker should used after initiation of alpha blocker if HR Treatment: Surgery Rxofchoice Adrenocortical carcinoma Rare (1:1.7 million) Most large tumors at time of Dx >6 cm (90%) May be hypersecretory Cushing s syndrome May present as a mixed syndrome both Cushing s and virilizing features. One-half of pts no recognizable endocrine syndrome 0% to 25% of incidentaloma 25

26 Adrenocortical carcinoma Metastases to the lymph nodes, liver, and lungs Poor prognosis (median survival 18 mo) Plasma dehydroepiandrostenedione (DHEA) sulfate levels a potential marker for malignant adrenocortical lesions Imaging: CT MRI Adrenocortical carcinoma Treatment: Complete surgical resection chance for cure. the only Mitotane used both as an adjuvant to surgery & as primary Tx in individuals with unresectable or metastatic disease. Moderate survival advantages Significant gastrointestinal and neurologic toxicity No role of chemoradiation 26

27 Non functioning mass Cortical adenoma The majority of incidentally discovered adrenal masses in pts with no prior Hx of cancer. Benign Size ranged from cm (mean 3.3 cm) Mostly non hypersecretory 5-47% secrete cortisol % secrete mineralocorticoid Androgen/estrogen secreting adenoma Rare The Clinically Inapparent Adrenal Mass: Update in Diagnosis and Management, GEORG MANSMANN, Endocrine Reviews, April 2004, 25(2):

28 Adrenal metastases At autopsy: 8% to 38% of pts with extra-adrenal malignancies. Non-adrenal cancer with a unilateral adrenal mass: 32% to 73%. Lesions < 3 cm are less likely to be malignant. Frequently bilateral. Primary tumors : breast, lung, and renal cell carcinomas, melanoma and lymphoma Dx: Imaging or FNA biopsy (after excluded pheochromocytoma) Adrenal Incidentaloma L. Michael Brunt, M.D, World J. Surg. Vol. 25, No. 7, July 2001 Adrenal metastases Treatment: A unilateral adrenal metastasis in a pt who with disease-free surgical resection Treat primary diseases 28

29 Common syndromes of adrenal Diagnosis Features Biochemical test Pheochromocytoma High blood pressure, catechol symptoms Urine and plasma free metanephines Primary aldosteronism High blood pressure, low K, low plasma renin activity Plasma aldosterone to renin ratio Adrenocortical carcinoma Cushing/silent cushing Virilization/feminizat ion Cushing symptoms/ normal Urine 17-ketosteroids Overnight 1-mg dexamethasone test Assessment of malignant potential Imaging phenotype Tumor size Image-guide needle biopsy ( is very limited used) Iodocholesterol scintigraphy (NP59) Adrenal Incidentaloma L. Michael Brunt, M.D, World J. Surg. Vol. 25, No. 7, July

30 Adrenal incidentaloma Adrenal incidentaloma 24 hr metanephrines & catecholamine Low dose (1mg) dexamethasone Suppression test PAC/PRA if HT No Functioning Adrenal tumors? No Imaging : CT/MRI Suspected malignancy Yes Yes Surgery <4 cm Tumor size 4-6 cm F/U: 1ximaging after 6-12 mo Endocrine evaluation 1/yr for 4 yrs >6 cm Search for extra adrenal primary CA Consider percutaneous BX Surgery 30

31 Adrenalectomy Selection of operative procedure Laparoscopic (gold standard) Opened 31

32 Lap adrenalectomy For most of patients Lap adrenalectomy was appropriated Short hospitalization Less morbidity (wound,pulmonary, infectious) Reduce pain and blood loss Approach Transabdominal lateral frank (Most common) Anterior abdomen In bilateral adrenalectomy Indication for Laparoscopy Laparoscopic adrenalectomy Non-malignant adrenal tumor < 8-10 cm Solitary unilateral adrenal metastasis Small hormone-secreting adrenal tumor overall conversion rate to open adrenalectomy is less than 5% 32

33 C/I for Lap adrenalectomy Previous upper abdominal surgery Large adrenal gland ( > 10 cm) Carcinoma of adrenal gland Feminizing tumor of adrenal gland (malignancy risk) 33

34 Open adrenalectomy 1. Transabdominal approach 2. Thoracoabominal approach 3. Posterior approach 4. Retroperitoneal approach Opened adrenalectomy Transabdominal Tumor with extraadrenal extension or local invasion Tumor with suspected regional LN metastasis Thoracoabdominal Large tumor with major vascular invasion (IVC) can t controlled intraabdomen 34

35 Opened adrenalectomy Open posterior (prone) Small unilateral tumor, not amenable for lap approach Extensive pre-op upper abdominal surgery Retroperitoneum Post op complications Hemorrhage (most common) Conversion form Lap open bleeding from major vessels Vascular occlusion Ligation of renal vv Solid organ Injuries Tumor embolization Cushing's syndrome port site infections ( 5-10%) subphrenic abscesses 35

36 Postoperative Care Return of bowel function within 3 to 4 days Discharge on postoperative day 5 to 7 Recent research 36

37 Don t forget 37

38 MEN 2 A Thyroid : MTC 100% Adrenal : Pheochromocytoma 50 % Parathyroid : Hyperplasia 20 % 2 A & 2 B : lichen planus amyloidosis, Hirschsprung s disease 38