Anatomy and Path of Adrenal gland

Adrenal glands are located in the ___________ space

Perirenal

Adrenal gland

1/3 size of the kidney

Situated on the medial upper poles of the kidneys

Endocrine glands - produce substances transported by the circulatory system

Adrenal glands are surrounded by:

Gerota fascia

Right adrenal gland

Triangle shaped

Medial to the right lobe of the liver

Posterior to IVC

Superomedial anterior aspect of the upper pole of kidney

Lateral and anterior to the diaphragm

Left adrenal gland

Crescent shaped

Medial to spleen

Posterior to the pancreas tail and stomach

Lateral to Ao

Lateral and anterior to the diaphragm

Splenic artery and vein course between the:

Pancreas and left adrenal gland

Left adrenal mass can cause:

Anterior displacement of the pancreatic tail and splenic vessels

Right adrenal mass can cause anterior displacement of:

IVC

Adrenal mass can cause ________ displacement of the associated kidney

Inferior

Adrenal cortex

Outer layer of tissue of adrenal gland

Composes 90% of the gland

Controlled by the pituitary gland and adrenocorticotropic hormone (ACTH)

ACTH stimulates the cortex to increase adrenal function

Increased adrenal function slows the pituitary production of ACTH

Zona glomerulosa, fasciculata, reticularis

Endocrine function of the adrenal gland

Synthesizes cortisol, androgens, estrogen, progesterone and aldosterone

Zona glomerulosa

Produces mineralocorticoids when stimulated by aldosterone, responsible for fluid and electrolyte regulation

Zona fasciculata

Cortisol regulation, responsible for metabolism regulation

Zona reticularis

Secretes estrogens and androgens; promotes reproductive organ development

Medulla of adrenal gland

Synthesizes catecholamines (epinephrine and norepinephrine) in the chromaffin cells

Responsible for fight and flight mechanism

Epinephrine

AKA adrenaline

Increases heart rate and blood pressure

Released in response to stress

Redirects blood from GI tract and skin to muscles

Norepinephrine

Increases heart rate and blood pressure

Continuously release to control blood pressure

Causes vasodilation

Arteries that supply adrenal glands

Superior suprarenal artery originates from the inferior phrenic artery

Middle suprarenal artery originates from the abdominal aorta

Inferior suprarenal artery originates from the renal artery

Right suprarenal vein drains into the …

IVC

Left suprarenal vein drains into the left renal vein or

Left inferior phrenic vein

ACTH - Adrenocorticotrophic hormone

Produced by the pituitary gland

Increased ACTH released with decreased adrenal function

Serum levels increase with Addison disease, Cushing disease, adrenal insufficiency, adrenal tumors, pituitary tumors

Serum levels decrease with adrenal hyperfunction

Aldosterone

Serum levels used to assess adrenal function

Secreted by the adrenal cortex

Regulates sodium and water levels to control systemic bp

Levels tested in the blood or urine

Increases with adrenal adenoma, adrenal adenocarcinoma, bilateral adrenal hyperplasia, Conn syndrome, renovascular HTN

Decreases with Addison disease

Cortisol

Secreted by the adrenal cortex

Estrogen, testosterone

Aids in glucose metabolism, inflammatory response, systemic blood pressure regulation

Increases with pituitary tumor, hyperpituitarism, Cushing syndrome, Cushing disease, adrenal hyperplasia

Androgens

Secreted by adrenal cortex

Estrogen and testosterone

DHEA-S is secreted by the adrenal glands and the body turns it into testosterone

Used to eval pts with suspected congenital adrenal hyperplasia, infertility, delayed or early puberty, Cushing disease or adrenal tumor

Increases with Cushing syndrome, PCOS, and abnormal adrenal function

USA Adrenal glands

Difficult to see in adults

Cortex is more hypoechoic than the medulla and surrounding fat

Medullar appears as echogenic linear structure within gland

Gland is flat, triangular or cone shaped

Right adrenal gland is best visualized __________ at the midaxillary or anterior axillary line; use the liver as an acoustic window

Intercostally

The left adrenal gland is tougher to visualize but can be evaluated from the __________ or intercostally at the midaxillary or posterior axillary line; use the spleen as an acoustic window

Epigastrium

Indications for US of adrenal gland

Decreased hematocrit

Systemic HTN

Virilism

Hirsutism

Adrenal gland

Wolman disease

Autosomal recessive disorder

Causes excessive lipid storage in liver, spleen and adrenal glands

Usually fatal in the first 6 months

Wolman disease USA

Hepatosplenomegaly

Massive adrenal gland enlargement

Adrenal hemorrhage

Most commonly occurs in newborns; caused by birthing process

In adults its related to trauma

Adrenal glands are highly vascular

Associated with jaundice and anemia

Usually affects right side

Resolves spontaneously

Labs adrenal hemorrhage

Decreased hematocrit

USA Adrenal hemorrhage

Mass with varied echogenicity with age of thrombus

Use color Doppler to aid in differentiation from adrenal mass

NO FLOW IN HEMORRHAGE

Adrenal hemorrhage

Pheochromocytoma is most commonly _________

Benign

Pheochromocytoma is most commonly hyperfunctioning with

Increased production of catecholamines

Pheochromocytoma is composed of what cells

Chromaffin

Pheochromocytoma

Originates in the medulla tissue

Average size: 5-6cm

Right is more commonly affected

Associated with MEN syndrome, Von Hippel Landau disease and tuberous sclerosis

Pheochromocytoma Labs

Increased secretion of dopamine, epinephrine and norepinephrine

Pheochromocytoma symptoms

Uncontrolled HTN, anxiety, headache, N/V, sweating, tachycardia, palpations, weight loss

Pheochromocytoma USA

Usually an echogenic or hypoechoic mass

Highly vascular

Demonstrates attenuation/propagation speed artifact due to fat content of lesion

May see calcs

Pheochromocytoma

Adrenal hyperplasia

Adrenogenital syndrome

ACTH elevation causes hyperplasia of adrenal tissues as they try to (unsuccessfully) produce more cortisol

Associated with Hirsutism

Can lead to ambiguous external genitalia in female fetus

Adrenal hyperplasia labs

Impaired cortisol synthesis causes increased ACTH production

Adrenal hyperplasia USA

Bilateral, diffuse gland enlargement

May see nodule formation that can be solid, cystic or complex

Adrenal myelolipoma

Originate in adrenal medulla

Contain bony and fatty elements

Adrenal myelolipoma USA

Hyperechoic, may blend into perirenal fat

Attenuation artifact demonstrated

May see diaphragm disruption due to propagation speed artifact; the decrease in the speed of sound in fatty tissue can cause the portion of the diaphragm that is posterior to the mass placed more posterior on image

Adrenal myelolipoma

Addison disease

Adrenocortical insufficiency, low aldosterone and cortisol production

High levels of potassium (hyperkalemia) and low sodium levels will reduce urine output and increase blood volume in body

Glands enlarged in acute stages

Decreased gland size in chronic stages

Addison disease is most commonly associated with

Autoimmune disorders

Addison disease is caused by

Hypersecretion of adrenocortical hormones from the pituitary gland (high ACTH levels) as it keeps trying to stimulate the adrenal gland to produce more corticosteroids

Addison disease symptoms

Fever, fatigue, hypotension, GI tract distress, weight loss, hyperpigmentation of the skin (skin has brownish discoloration)

Cushing Disease is caused by

Excessive secretion of ACTH by the pituitary gland which leads to the overproduction of cortisol

FROM PITUITARY TUMOR

Labs for Cushing Disease

Hypersecretion of ACTH by pituitary gland causes increased cortisol production by the adrenal gland which then leads to increased glucose production (blood sugar)

Cushing Disease

Characterized by truncal obesity, hirsutism, amenorrhea, HTN, fatigue, hyperglycemia

Glands can be diffusely enlarged with areas of necrosis/hemorrhage

Can lead to Cushing syndrome

Cushing syndrome are most commonly caused by

Steroid based medications, such as prednisone

Cushing syndrome caused by excessive

Cortisol secretion due to adrenal hyperplasia, adenoma, or carcinoma

Cushing syndrome labs

High cortisol levels with normal ACTH levels, hypophosphatemia

Cushing syndrome caused by Cushing disease: __________

Cushing syndrome caused by steroid use or adrenal tumor: ___________

Elevated ACTH and cortisol; elevated cortisol only

Cushing syndrome

Body responds to chronic high levels with normal ACTH levels, hypophosphatasia

Characterized by truncal obesity, purple stretch marks on sides and lower abdomen (striae), hirsutism, amenorrhea, HTN, fatigue, hyperglycemia

Other related findings include diabetes, HTN, edema, cardiomegaly, adrenal rest tumors (scrotal tumors)

Glands can be diffusely enlarged with areas of necrosis/hemorrhage

Conn syndrome is caused by

Aldosterone-producing adrenal tumor; aldosteronoma

Conn syndrome

Labs: increased levels of aldosterone, elevated serum levels of sodium, decreased serum levels of potassium, will increase urine output and reduce blood volume in the body

Glands can be diffusely enlarged with areas of necrosis/hemorrhage

Most common adrenal tumor

Adenoma

Most common adrenal incidental finding

Adenoma

Most common type of adenoma

Non-functional

• Does not require treatment

Adenoma

Unilateral mass

Usually <3cm

Functional or non-functional

Larger lesions are more likely to be functional and may cause Cushing syndrome or Conn syndrome

May be part of multiple endocrine neoplasia syndrome

Rapid contrast washout on multiphase CT exam can help differentiate from adrenal malignancy

Functional adenoma

Causes increased adrenal function and requires treatment/surgery

USA Adenoma

Hypoechoic solid mass formed in cortical tissue of gland

Usually homogeneous with NO necrosis or cystic components

Adrenal adenoma

Adrenal cortical cancer

Neoplasm formation due to abnormal proliferation of cortical cells

Can get pretty large in size >6cm

Elevated androgen levels

Associated with hirsutism due to excessive androgen production

Most pts have Cushing syndrome b/c the tumor causes excess cortisol production

NO contrast washout on CT

USA Adrenal cortical cancer

Demonstrates complex appearance with hypoechoic solid components and cystic changes

Very aggressive and mets is common

Can invade renal vein and IVC

Adrenal cortical cancer

2nd most common abdominal tumor in pediatric pts

Neuroblastoma

Neuroblastoma

Malignant tumor of the medullar of the adrenal

Usually presents in younger children, <5yrs of age

Can also occur in the chest and neck area

Symptoms: tachycardia, night sweats, headaches

Requires surgical removal

Neuroblastoma Labs

Increased levels of norepinephrine, epinephrine and dopamine in the blood and urine

Neuroblastoma USA

Large echogenic, heterogeneous mass that does NOT distort renal contour, but can displace the kidney inferiorly

Eval kidney contour related to the mass to determine adrenal vs. renal origin

Use color to eval internal vascularity → will have color

Neuroblastoma

Adrenal lymphoma

Adrenal glands are commonly affected by Non-Hodgkin lymphoma

Bilateral

Diffuse enlargement of the gland with varied echogenicity

Adrenal mets

Most common primaries are lung, breast, kidney and melanoma

Can be unilateral or bilateral

Demonstrate delayed contrast without on CT evaluate

Solid mass with heterogenous appearance

Adrenal mets

The right adrenal gland is ________ shaped

Triangle

Which of the following controls the function of the adrenal cortex?

Cortisol

Aldosterone

Adrenocorticotrophic hormone

Epinephrine

Adrenocorticotrophic hormone

__________ is responsible for fluid and electrolyte regulation, while ________ is responsible for metabolism regulation

Aldosterone; cortisol

Norepinephrine and epinephrine have what effect on the body?

Control heart rate and blood pressure

Aldosterone levels increase with:

Adrenal adenoma, adenocarcinoma and bilateral adrenal hyperplasia

Which of the following levels decreases with Addison disease or adrenal insufficiency

Cortisol

Norepinephrine

Testosterone

Epinephrine

Cortisol

What is monitored in pts with infertility or delayed/early puberty

Testosterone

What levels will be reduced in lab testing of a newborn with an isolated adrenal hemorrhage

Hematocrit

Which of the following is an adrenal mass composed of bony and fatty elements that result in propagation speed artifact

Myelolipoma

Pheochromocytoma

Lymphoma

Adenoma

Myelolipoma

What is caused by hypersecretion of ACTH that results in no change to cortisol production

Addison disease

What is caused by hypersecretion of ACTH by the pituitary gland which leads to the overproduction of cortisol

Cushing disease

Which of the following presents as hypernatremia and hypokalemia

Conn syndrome

Adrenal adenoma is part of what syndrome

MENS

A pheochromocytoma is part of what syndrome

VHL syndrome

Most pts with adrenal cortical cancer also have:

Cushing syndrome

What characteristic differentiates a renal mass from a neuroblastoma in an infarct

Renal contour