The Adrenal Glands Holdorf

Outline  Location  Quick facts  Spatial anatomy  Normal anatomy  Cortex  Medulla  Disorders  Cushing’s disease  Cortical Carcinoma  Pheochromocytoma  Addison’s Disease  Neuroblastoma  Adenoma  Myelolipoma

Outline  Adrenal lymphoma  Adrenal Metastases  Adrenal Hemorrhage  Adrenal Cortical cancer  Kaposi’s Sarcoma  Adrenal Cysts

 The Kidneys and adrenal glands lie within the peri-renal space and are separated from the pararenal spaces by the anterior and posterior renal fascia (Gerota’s Fascia).

ACTH  Adrenocorticotropic hormone (ACTH), also known as corticotropin is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological stress. Its principal effects are increased production and release of cortisol by the cortex of the adrenal gland.

The following structures are located in the retroperitoneum:  Kidneys  Adrenal Glands  Ascending and Descending Colon  2 nd, 3 rd, and 4 th parts of the duodenum  Pancreas  Aorta and IVC  Ureters  Renal vessels  Superior mesenteric vessels  Gonadal vessels  Lymphatics  Prostate

Adrenal Gland Quick Facts  Smallest paired organs found within the abdomen  Located at the level of the 11 th or 12 th thoracic rib  2-3 cm in width x 4-6 cm in length and 3-6 m in thickness  Composed of CORTEX and MEDULLA

Spatial anatomy of the Adrenal Glands  Right Adrenal Gland is posterior to the IVC  Right Adrenal Gland is anterior to the crus of the diaphragm  Right Adrenal Gland is inferior to the liver  Left Adrenal Gland is situated between the spleen and upper pole of the Left Kidney  Left Adrenal Gland is posterior to the tail of the pancreas

More facts…  The Adrenal Glands play a significant role in the maintenance of homeostasis through hormone secretion  CT Scan is regarded as the gold standard imaging modality for the adrenal gland

Adrenal Glands  The adrenal glands and kidneys are located within the perirenal space  The right adrenal gland is shaped like a triangle and pyramid. It is located on the superior, anterior and medial aspect of the upper pole of the right kidney. Portions of the gland extend posterior to the IVC. The curs of the diaphragm lies medial and posterior to the right adrenal gland.  The left adrenal gland is crescent shaped and is located antero-medial to the upper pole of the left kidney. The aorta and curs of the diaphragm are located medial to the left adrenal gland. The tail of the pancreas is located anterior to the left adrenal gland.

Cross-Sectional Adrenal Glands

Normal Anatomy  The adrenal cortex is hypoechoic and typically is less echogenic than the surrounding retroperitoneal fat.  The adrenal medulla is seen as an echogenic linear structure within the adrenal gland.  Three arteries supply each adrenal gland:  Suprarenal branch of the inferior phrenic artery  suprarenal branch of the aorta  suprarenal branch of the renal artery  A single vein drains each adrenal gland:  Right suprarenal vein drains into IVC  Left suprarenal vein drains into the left renal vein (just like the left Gonadal vein)

Blood Supply to the Adrenal Gland

Normal Adrenal Glands

Adrenal Cortex  The adrenal cortex produces steroid hormones. (The pituitary gland and Adrenal gland “watch” each other and work in harmony).  Mineralocorticoids (aldosterone)  Glucocorticoids (cortisol)  Androgens  The adrenal cortical hormones (ACH) are regulated by the adrenocorticotropic hormones (ACTH) of the pituitary gland.

The adrenal Cortex–X section

Adrenal Cortex cont…  The adrenal gland and the anterior pituitary gland function together to regulate hormone production. A decrease in adrenal cortical function leased to an increased ACTH which then stimulates the adrenal cortex. An increase in adrenal hormones leads to a drop in ACTH secretions, which in turn leads to a drop in the activity of the adrenal cortex.  Tumors of the adrenal gland and anterior pituitary gland may overproduce or under produce ACTH and ACH.

Adrenal Medulla  The adrenal medulla produces  epinephrine (adrenalin  Norepinephrine  Adrenal masses  Sonographic appearances of adrenal masses does not allow differentiation between adenoma, carcinoma, Pheochromocytoma and metastases.

Adrenal Medulla x-section

Adrenal Medulla cont…  Adrenal Adenoma  Adrenal adenomas can be hyper functioning or nonhyperfunctioning. Adrenal cortical hyper functioning can be caused by adrenal hyperplasia (congenial or acquired), adenomas or adenocarcinomas. The following syndromes are the result of adrenal hyper functioning:

 Cushing’s syndrome-excessive cortisol secretion associated with adrenal adenomas.  Cushing’s disease – excessive cortisol secretion due to increase in ACTH form a pituitary adenoma.  Conn’s Disease – excessive aldosterone secretion associated with adrenal adenoma.  Hirsutism – may be caused by androgen secreting adrenocortical and ovarian disorders (Cushing’s syndrome, Cushing’s disease, polycystic ovarian syndrome).  When endocrine studies are negative, indicating a non-hyper functioning adrenal mass, resection is based on its size (>3cm)  In patients with a known primary malignancy, biopsy is often performed to exclude metastatic disease.

Adrenal cortical Carcinoma  Adrenal cortical carcinoma is a rare tumor with a poor prognosis. The majority of patients present with Cushing’s syndrome. Many patients present with metastatic involvement.  Differentiation from a benign adenoma is difficult. Tumor removal (or biopsy) is based on size (3-6 cm)  Adrenal cortical carcinomas have a tendency to invade the renal veins and IVC.

Pheochromocytoma  Benign  Know as 10% tumor  Rare  Appears in 4 th to 6 th decade of life  Arise from adrenal medulla  Secrete non-epinephrine and epinephrine

Pheochromocytoma  Pheochromocytoma originates in the adrenal medulla but may occur in ectopic locations such as along the para-aortic sympathetic nerve chair. The majority of pheochromocytomas are benign.  Pheochromocytomas secrete  Norepinephrine  epinephrine  Pheochromocytomas are associated with multiple endocrine neoplasia (MEN) AKA Von Hippel-Lindau disease.

ADDISON’S DESEASE  Addison’s disease, also known as primary adrenal insufficiency, is a long term endocrine disorder in which the adrenal glands do not produce enough steroid hormones. Symptoms generally come on slowly and may include abdominal pain, weakness, and weight loss. Darkening of the skin in certain areas may also occur. Under certain circumstances an adrenal crisis may occur with low blood pressure, vomiting, lower back pain, and loss of consciousness. An adrenal crisis can be triggered by stress, such as from an injury, surgery, or infection. [1] [1]

Adrenal Neuroblastoma  Adrenal Neuroblastoma is a malignant tumor that occurs 65% of the time in the abdomen (45% adrenal medulla and 25% sympathetic nervous chain). It typically presents as a palpable abdominal mass in children.  Most common extra cranial solid childhood malignancy.  Most common tumor occurring during infancy.  Age ranges from 1-10 years (36% before 1 yr, 75% before 4 years). Age at diagnosis is typically younger than that for Wilm’s tumor.

Adrenal Neuroblastoma  Accounts for approx. 8% of childhood cancers  It typically displaces the kidneys inferiorly into the pelvis, opposed to the Wilm’s tumor, that originates from and destroys the kidney.  Increase in urinary by-products  More than 50% of patients present with metastatic disease.

Adenoma  Benign  Found in 3% of adult autopsies  Most are non functioning  Reported in patients with  Hypertension  Diabetes  Hyperthyroidism  Renal cell carcinoma

Adenoma  Hyper-functioning adrenal adenomas most commonly give rise to:  Cushing’s syndrome (caused by excessive cortisol secretion)  Conn’s Disease (Caused by increased aldosterone) Adenoma Tumors tend to be less than 2 cm in size

Adrenal Adenoma

Myelolipoma  Myelolipomas are benign, nonfunctioning adrenal masses that contain fat and bone elements.  Sonographically, are seen as hyperechoic masses in the adrenal bed.  Associated with propagation speed artifact due to fat composition.

Myelolipoma  Benign  Rare, non functioning tumors  Composed of varying proportions of fat and bone marrow  Mostly less than 5cm in diameter

 Lymphoma  Malignant tumor  Rare  Hypoechoic  May arise from lymphoid element found in normal adrenal or contiguous spread from retroperitoneal diseases  Necrosis and calcifications are rare

Adrenal Lymphoma  Adrenal involvement with lymphoma is common and frequently bilateral. Involvement may be diffuse, resembling hyperplasia or mass-like.  Non-Hodgkin disease is the most common cell type.

Adrenal Metastases  The adrenal glands are the 4 th most common metastatic site after lungs, liver and bone. The most common primary sites are lung, breast, skin (melanoma), kidney, thyroid, and colon cancers.  Differentiation from a unilateral adrenal mass (benign adenoma vs. a metastatic lesion) is difficult in a patient with a primary cancer.

Adrenal Hemorrhage  Adrenal hemorrhage is most common in the neonate. They are caused by the large size of the neonatal adrenals and their high degree of vascularity which make them vulnerable to birth trauma.  Sonographically, the appearance of an adrenal hemorrhage varies due to blood coagulation. The normal evolution of a hematoma ends with a pseudocyst formation. If a mass is identified adjacent to the adrenal glands of a newborn, it is most likely a hemorrhage.

Adrenal Hemorrhage

Other  Adrenal cortical cancer  Rare  More common in females in the 4 th decade  Highly malignant: has tendency to invade the adrenal veins, IVC, and lymph nodes  Recurs following surgery

 Kaposi’s Sarcoma  Patients with AIDS are more affected  90% or more of the adrenal gland is damaged by infection  Adrenal insufficiency occurs

Kaposi's Sarcoma  Kaposi's sarcoma is a cancer that causes patches of abnormal tissue to grow under the skin, in the lining of the mouth, nose, and throat or in other organs.  The patches are usually red or purple and are made of cancer cells and blood cells. The red and purple patches often cause no symptoms, though they may be painful.  If the cancer spreads to the digestive tract or lungs, bleeding can result. Lung tumors can make breathing hard.

Kaposi’s Sarcoma

Adrenal Cysts  Rare  Benign  Typically unilateral  3 rd to 5 th decade  3:1 female ratio  Asymptomatic unless compression of adjacent structures: Abdominal pain, nausea, and back pain.

Adrenal Cysts

Adrenal Gland Cyst

Questions:  What is the most common adrenal mass in the newborn? Adrenal hemorrhage What is the most likely diagnosis in a newborn with an abdominal mass and decreasing hematocrit?  Wilm’s tumor  Adrenal Neuroblastoma  hepatoblastoma  adrenal hemorrhage