Surgical Disease of the Adrenal Gland (Part I) Roc McCarthy, D.O.

Anatomy Physiology The incidental adrenal mass Fun facts Pheochromocytoma

Adrenal Gland Cortex - mesoderm Medulla - neuroectoderm Renal agenesis, found in normal anatomic position Size- 5 x 3 x 1 x 5 cm Retroperitoneal structure, contained in its own sub-compartment w/in Gerota’s fascia

Adrenal Gland Blood supply Arterial - receives 7cc/gram minute - 3 arterial sources of flow: 1. Inferior phrenic artery 2. Aorta 3. Renal artery Venous – single main vein most important surgical structure - right → post IVC - left → renal vein

Nerve Supply Medulla - sympathetic branches - epinephrine - norepinephrine Cortex – none Lymphatics- lateral aortics (renal artery to diaphragm)

Hypothalamic-Pituitary-Adrenal Axis

Layers of Adrenal Gland

Aldosterone Primary stimulus for release is angiotensin II Other: ACTH, low serum Na, elevated K, JGA via low kidney perfusion

Adrenal Medulla Distinct from cortex embryologically (neuroectoderm) Secretes catecholamines sympathetic stimulation (mainly epinephrine but also norepinephrine and dopamine) If pt. has excess of BOTH epi and norepi, the tumor is in the adrenal gland

The Incidental Adrenal Tumor 0.5 – 5% of abdominal CTs show abnormal adrenal glands 85% of adrenal masses are nonfunctional and BENIGN Def. of incidental mass: - >1cm - discovered on exam for non-adrenal cause - absence of signs or symptoms of adrenal disorder

Questions to be asked: Is the mass functional? Any physical signs or symptoms? Is there biochemical evidence of activity: 1. Pheo screen 2. Potassium level 3. Glucocorticoid screen Is the mass malignant? Any history of another malignancy? Is imaging suggestive of malignancy?

Nature of Incidentally Found Adrenal Masses Review of 2,005 incidentally-discovered adrenal masses: - Nonfunctioning adenoma 82% - Functioning: Cushing’s 5% Pheo 5% Aldosteronoma 1% - Malignancy: Metastasis 3% ACC 4% Young WF, et al. Endocrinol Clin N Am. 2000

Good to Know Facts! If the adrenal gland has fat density material, it is by definition a benign myelolipoma If pt. has a known primary cancer, the adrenal mass with be mets from that site 50% of time Overall 2-4% of adrenal masses are ACC If mass >6cm, ACC 65%

Incidental Adrenal Mass Initial Evaluation History and physical exam Look for signs of hormonal syndromes Search for occult malignancy CXR Stool for occult blood Mammogram (women only)

Extent of Endocrine Evaluation? Serum K (if HTN) → Conn’s Plasma metanephrines: most sensitive test for pheo 24-hr urine cortisol (Cushing’s)

Diagnosis: Imaging Rare for a nonfunctional adenoma to become functional MRI- Both ACC and pheo are hyper-intense in T2 images (light up from T1 to T2)

CT Adenoma Characteristics Sharp margins Smooth, homogenous, lipid rich Most <10 Hu on noncontrast images Washout >50% @ 15 min

Incidental Adrenal Mass Management Hormonally active → surgical removal > 5 cm → removal (with a scalpel) < 3 cm observe Surveillance Recommendations: Old: - CT at 6 months - Annual endocrine eval for 4 years New: If mass stable on scans @ 3m and 1 yr then no further workup

Pheochromocytoma Incidence and Presentation - symptoms → release of epi/norepi - hypertension present 90% cases - orthostatic hypotension (low plasma vol) - 30% of pheo’s found at autopsy and cause of death cardiovascular disease - micturition syncope

Pheo (cont’d) Triad: headache, tachycardia, diaphoresis Other symptoms: Pallor, flushing, palpitations, abd/chest pain, weakness, N/V, psychosis Small tumors more likely symptomatic ALL patients regardless of age, have a complete cardiac work-up before surgery

Pheochromocytoma Rule’s of 10 Bilateral Familial (non-sporadic) Pediatric Malignant Normotensive Extra-adrenal Multiple *Childhood presentation breaks the rules- 25% bilateral, multiple, extra-adrenal

Pheo- The Diagnosis Plasma free metanephrines- most sensitive test -seen 99% of patients 24° urinary catecholamines (2x normal is diagnostic) VMA Clonidine suppression test (0.3mg oral, test 3 hrs later) >50% reduction catecholamines NO pheo

MEN I

MEN IIA

MEN IIB

Pre-op Management Early alpha blockade??? Goal to control hypertension- phenoxybenzamine Do NOT use b-blocker before alpha IV hydration Prevent cardiac arrhythmias

Pheo Post-op - hypotension (most common) sec to secondary to hypovolemia Surgical outcomes - excision does NOT always lead to long- term cure - recurrence 5% benign 10% malignant

Part II Conn’s syndrome Cushing’s syndrome Addison’s disease Adrenal cortical carcinoma Metastatic disease to adrenal gland Principles of adrenalectomy