Pathology of the Adrenal Glands Flashcards
Pathologic Conditions of the Adrenal Glands
Adrenal cortical syndromes Addison’s disease Waterhouse-Friderichsen syndrome Adrenogenital syndrome Conn’s syndrome Cushing’s syndrome Adrenal cysts Adrenal haemorrhage Adrenal tumours Benign Malignant Metastases Adrenal medulla tumours
Addison’s Disease (adrenocortical insufficiency)
Primary adrenal insufficiency due to destruction of the adrenal cortex
Majority of the cortical tissue is often destroyed before adrenal insufficiency is diagnosed.
Affects men and women equally; not related to age
Primary causes of reduced adrenal cortical tissue:
Autoimmune process (70% of cases in developed world)
Tuberculosis (TB)
Inflammatory process
Primary neoplasm
Metastases
Clinical presentation – Addison’s syndrome: Weight loss / LOA General weakness Hyperpigmentation (bronzing of the skin) Hypotension Hypoglycaemia May have renal failure
Low levels of cortisol and aldosterone
Waterhouse-Friderichsen syndrome (haemorrhagic adrenalitis)
Rare condition; most often in children and young adults
Adrenal gland failure due to bleeding into the adrenal gland
Caused by severe bacterial infection (rarely can be caused by renal vein thrombosis)
Clinical presentation: Shock Extensive haemorrhage within the skin Pulse rapid and hard Vomiting, often with blood Cyanotic Convulsions
Ultrasound presentation - Waterhouse-Friderichsen syndrome:
Adrenal hemorrhage may occur bilaterally in 20%
Depending on the stage of haemorrhage, the echotexture can range from a hyperechoic to an anechoic suprarenal mass in the region of the adrenal gland
Over time as the haemorrhage ages, the mass may shrink and calcifications may appear as focal echogenic areas with acoustic shadowing
Check for renal vein patency, just in case
Adrenogenital syndrome
Excessive secretion of androgens
Caused by late-onset congenital adrenal hyperplasia, familial glucocorticoid resistance, adrenocorticotropic hormone-dependent Cushing’s syndrome, and androgen-secreting adrenal neoplasms
Clinical presentation:
Male – prepubescent males have signs of masculine development (deepening voice, incr body hair); may not be noticeable in adult men due to lack of obvious symptoms
Female – varying degrees of masculinisation including hirsutism, temporal balding, acne, increased muscle bulk, deepening voice, loss of secondary sex characteristics (menstrual dysfunction, atrophy of uterus, decr breast size)
Conn’s syndrome
Excessive secretion of aldosterone
Present in about 10% of people with hypertension; 30 – 50 years of age
More often in women than men
70% due to an adrenal adenoma, esp in women; men – more likely due to adrenal hyperplasia
Contralateral adrenal atrophy can occur
Clinical presentation:
Hypertension
Muscle weakness and cramps
Cushing’s syndrome
Excessive secretion of glucocorticoids More common in women, 40 – 50 years ACTH independent; due to adrenal tumours (benign and malignant) in 20% of cases ACTH-secreting tumour in 80% of cases Pituitary adenoma 68% Ectopic production 12%
S&S: Truncal obesity and pencil-thin extremities “Moon face” or “buffalo hump” Hypertension and renal stones Irregular menses
Adrenal cysts
Rare <1% incidence; no clinical symptoms when small
Affects women 3x more than men
Benign
Clinical presentation:
Pain or swelling
No symptoms in 40% (incidental finding)
Ultrasound presentation:
May be unilateral, and unilocular or multilocular
Well-defined and anechoic
Thin wall; may calcify
Haemorrhage can occur within cysts – echogenic debris, fluid/fluid level, septae, or calcifications
Adrenal hyperplasia
Most common cause: Congenital adrenal hyperplasia (CAH): Autosomal recessive disease Lack of 21-hydroxylase enzyme Low levels of cortisol and high levels of androgens – development of male characteristics in females and early puberty in both boys and girls
Ultrasound presentation:
Usually hypoechoic, esp in cortical zone
Appear plump and elongated; usually moderately enlarged
Demonstration of the medulla can exclude diffuse infiltration of tumour or lymphoma
Adrenal haemorrhage
Very rare in adults
Usually caused by severe trauma or infection
Post-traumatic haemorrhage usually unilateral and does not cause any major clinical problem
Bilateral haemorrhage may cause adrenal insufficiency
Neonatal presentation from trauma of birth – usually presents at 2 – 7 days old
Ultrasound presentation:
Varied, depending on stage of haemorrhage
Early stage – anechoic, becoming solid and echogenic
Progressively heterogeneous with time
Chronic stage – central cystic components and calcification
Adrenal tumours
Ultrasound is used to:
Characterise an adrenal mass as cystic or solid
Evaluate the position and patency of the IVC, draining veins, and renal veins
Evaluate tumour invasion into an adjacent structure
Determine the origin of a large retroperitoneal mass
Follow-up scan of an adrenal mass that is not surgically removed
Adrenal tumours:
Can be benign or malignant
Location: adrenal cortex or adrenal medulla
Adenoma
High incidence of adrenal adenomas exists in older patients with diabetes or hypertension
Adrenal lesions are usually less than 3 cm
Benign non-functioning adenomas are the most common primary adrenal tumour – 80%
Functional adenomas
Symptoms depends on site of tumour within the adrenal gland and what cells are active
Include pheochromocytomas, cortisol-producing or aldosterone-producing tumours
Can cause Cushing’s and Conn’s syndromes
Need to be treated if causing symptoms
Ultrasound findings – adenoma:
- Well-defined, round, slightly hypoechoic, homogeneous mass
- Vascularity hard to see, esp smaller ones
- Almost always detected as incidental finding
- If large, may compress adjacent structures
- Non-functional adenomas are often larger and can have a heterogeneous appearance with cystic necrosis, haemorrhage, and sometimes calcifications, making them hard to differentiate from a malignant lesion. Smaller non-functioning adenomas appear very similar to functioning adenomas – hard to differentiate sonographically
Myelolipoma
Rare non-functioning tumour of the adrenal cortex
Arises from fascicular zone
Consists of fat and bone marrow tissue
Similar to AML of the kidneys
Usually asymptomatic unless haemorrhage or large mass-effect on adjacent structures
Ultrasound findings – myelolipoma:
Well-defined, diffusely echogenic
Highly reflective due to fat content
May contain calcification
When small, hard to differentiate from adjacent fat
When larger than 4cm, diaphragmatic disruption appears due to propagation speed artefact – can confirm fatty nature of the lesion
DDx:
Exophytic renal AML
Lipoma
Pheochromocytoma
Adrenocortical carcinoma
Primary adrenal carcinoma; rare
Peak in children < 5 years or in adults in 40s and 50s
Can arise from any of the adrenal cortical zones
May be hyper-functional (up to 80%) or non-functional
Adrenal malignant tumors may cause Cushing’s syndrome, Conn’s syndrome, or adrenogenital syndrome.
Functional tumours tend to be smaller than non-functional tumors because they are typically diagnosed earlier due to symptoms
Up to 90% of non-functional tumours are > 6 cm
Hepatic mets and tumour thrombus within adrenal vein, renal vein, or IVC may be present at time of initial presentation of non-functioning tumour – poorer prognosis
Ultrasound presentation – adrenocortical carcinoma:
Well defined, often with lobulated borders
Heterogeneous solid masses, with some containing a central area of necrosis and hemorrhage, esp if larger, as well as calcification
Hypervascular with prominent feeder vessel
High incidence of invasion into the adrenal or renal vein, IVC, hepatic veins, and lymph nodes
Adrenal metastases
- Fourth most common site in the body for metastases, after the lung, liver, and bones.
- Most common malignant lesion in the adrenal glands; second overall most common adrenal lesion behind adenomas
- Bilateral involvement is seen around half the time; associated with metastatic disease elsewhere. Bilateral adrenal mets can cause adrenal insufficiency.
- Primaries include lung (most common), kidney, colon, breast, or melanoma.
- Can be directly invaded by RCC and HCC when aggressive tumours disrupt the fascial planes and invade the adrenal gland.
Ultrasound presentation – metastases:
- Irregular margins with irregular shape; may be ill-defined
- Heterogeneous and hypoechoic features
- Large masses may contain areas of necrosis and haemorrhage
- Vary in size; many > 4 cm. When small, can be hard to differentiate from benign adenomas on sonography
- In cases where there has been direct invasion by an adjacent primary, it can be difficult to distinguish the adrenal gland from the primary tumour.
Pheochromocytoma
- Tumour arising from the pheochromocyte cells in the adrenal medulla
- Functional tumours - secrete epinephrine and norepinephrine in excessive quantities
- 5 – 10% are malignant
- Small percentage of patients have ectopic adrenal pheochromocytomas rising from the neuroectodermal tissue; these tumours tend to be malignant
- Right adrenal gland affected more often than left
- Metastases can involve lymph nodes, liver, lung, and bone
Clinical presentation – pheochromocytoma:
Intermittent hypertension
Severe headaches
Heart palpitations
Ultrasound presentation:
Unilateral
When small, well-defined, round or oval mass with homogeneous echogenicity
May be large, bulky tumours, often larger than adenomas. Larger tumours can be more heterogenous due to necrosis, haemorrhage, degeneration, and calcification
Many have well-defined capsules or rims and moderate internal vasculature
