Adrenal Gland Pathology

EDIR Notes

• Hypovolemic shock due to sepsis presents with typical IVC and aorta caliber, and marked adrenal enhancement
• Pheochromocytoma, neuroblastoma, carcinoid tumors, medullary thyroid carcinoma, and ganglioneuroma all show abnormal MIBG activity
• Pheochromocytomas can metastasize to bone lymph nodes, liver, and lung
• Absolute contrast washout is calculated using the formula: HU at 60 sec - HU at 15 minutes HU 60 sec – HU at plain CT
• Elevated urine vanillylmandelic acid levels suggest pheochromocytoma
• Adrenal injuries and hemorrhage are more common on the right side
• VHL syndrome is associated with bilateral pheochromocytomas
• A signal intensity decrease of < 20% on chemical shift imaging suggests adrenal gland malignancy
• Adrenal hemorrhage commonly causes bilateral adrenal calcification in children and adults, predominantly unilateral and right-sided
• Wolman’s disease causes enlarged calcified adrenal glands and hepatosplenomegaly
• Signal drop on out-phase MRI images is indicative of adrenal adenoma
• MIBG scans are used to identify neuroblastomas and paragangliomas
• Adrenal cortical carcinoma displays peripheral enhancement with necrosis and calcification, and often invades the IVC with atrophy of contralateral adrenal gland
• Both adrenal adenoma and carcinoma may lead to Cushing's syndrome
• Adrenal adenomas have > 40% relative (RPW) washout, while pheochromocytomas and metastasis have RPW < 40% and absolute washout (APW) < 60%
• A signal drop exceeding 20% on out-phase images suggests intracellular lipid

Pediatric Adrenal Information

• Forniceal angle blunting is seen with grade IV vesicoureteral reflux, obliteration with grade V
• Adrenal cortical carcinoma occurs in childhood or the 4th-5th decade displaying precocious puberty and cushingoid features caused by MEN syndrome, and cystic areas due to hemorrhage and necrosis
• Stage T1 adrenal cortical carcinoma ≤ 5cm
• Stage T2 adrenal cortical carcinoma > 5cm
• Stage T3 adrenal cortical carcinoma extends outside adrenal into fat
• Stage T4 adrenal cortical carcinoma invades adjacent organs
• Enlarged calcified adrenal glands maintaining triangular configuration are seen in Wolman's disease
• Congenital adrenal hyperplasia is the most common cause of ambiguous genitalia
  • Virilization occurs in females
  • Precociousity occurs in males
• Elevated 17 hydroxyprogesterone levels are characteristic of Congenital adrenal hyperplasia
• Enlarged adrenal glands showing stippled echogenicity with “cerebriform pattern” are characteristic on USG

Succeeding: Get Through Question 31

• A 50-year-old with a resected pheochromocytoma develops hypertension, elevated urinary vanillylmandelic acid and an MIBG scan is performed
• Abnormal MIBG activity is most likely in metastatic sites like lung

Background MIBG Uptake

• Normal MIBG uptake: myocardium, liver, spleen, bladder, adrenal glands, salivary glands, nasopharynx, thyroid and colon
• Abnormal MIBG activity: phaeochromocytoma/ paraganglioma, neuroblastoma, carcinoid tumour, medullary thyroid carcinoma and ganglioneuroma
• Pheochromocytoma facts :
  • 10% are familial
  • 10% are bilateral or multiple
  • 10% are extraadrenal
  • 10% malignant
• Metastatic spread of pheochromocytoma in bone, lymph nodes, liver and lung

Question 37

• A man has a 35mm adrenal mass
  • Unenhanced CT: 30 HU
  • CT at 60 seconds after contrast: 90 HU
  • CT 15 minutes after contrast: 50 HU
• Lipid-poor adenoma is the most likely diagnosis

Lipid-Rich Adenomas

• Unenhanced CT attenuation value is <10 HU
• Threshold of 60% or higher for absolute contrast-enhancement washout gives a sensitivity of 98% and specificity of 92% in differentiating adenomas from non-adenomas
• Percentage of enhancement washout ¼ ([attenuation at 60 s – attenuation at 15min] / [attenuation at 60 sa attenuation on plain CT])100
• The calculation from the figures gives an absolute washout of around 66.6%

Question 33

• A 4 year old presents with precocious puberty and cushingoid features
• CT reveals a 10 cm mass in the left adrenal gland with cystic areas suggestive of haemorrhage and necrosis
• Normal Nodes and distant metastases
• Adrenal cortical carcinoma is the stage grouping

Adrenal Cortical Carcinoma

• Disease has two age peaks
  • One in early childhood (< 5 years)
  • Second in the fourth and fifth decades
• Preliminary staging relies on CT but MR is useful in vascular/local invasion
• T1/T2 tumors are ≤/ >5 cm without evidence of invasion
• T3 tumors extend outside the adrenal into fat
• T4 tumors invade adjacent organs
• Stage IV means there is metastases

Question 75

• A 70 year old smoker, with weight loss has
  • adrenal nodule on post-contrast CT: 3 cm, 60 HU
  • in-phase T1W images- isointense to spleen
  • out-of-phase T1W: returns significantly lower signal than the spleen
• An adrenal adenoma is the most likely diagnosis

Lipid-Rich Adenomas: Signal Dropout

• Signal dropout occurs during out-of-phase T1W sequences due to fat content
• Adrenal primaries and metastases don't share this feature
• Collision tumors arise when a metastasis occurs in an adrenal gland
  • Means the gland contains an adenoma
  • Signal characteristics of both conditions are seen on the T1W in- and out-of-phase sequences

Barret I: Contrast Washout

• Lesion: 2.3 cm adrenal lesion in a 62y/o
  • -2 HU before contrast
  • 56 HU on portal venous phase
  • 20 HU at 10 minutes
• An adenoma is the most likely diagnosis

Adenomas: Low Density Lesions

• Adenoma characteristically:
  • low density lesion (< 15 HU) due to fat
  • demonstrates a rapid wash-in and wash-out
  • density at 10 minutes is half seen in the portal venous phase

Question 2: Intravenous Contrast Medium Side-Effects

• Intravenous contrast medium can cause hypotension, bradycardia and shortness of breath.
• Adrenaline is used in the treatment of severe contrast reactions through intramuscular route
• Treatments range from leg elevation and oxygen for mild vasovagal episodes through to adrenaline and H1 antagonists with airway support for severe anaphylactic reactions.

Question 8: MIBG Examination and Tumor Staging

• MIBG is taken up by (at variable extent) - liver, lung, colon, stomach and thyroid
• Uncommon to see uptake in the adrenal glands with 1 131 MIBG, but faint uptake is commonly seen with 1231-MIBG
• MIBG is NOT taken up by the ovaries

Question 31 : Adrenal Calcifications on CT

• 4y/o presents with unilateral adrenal calcification on CT, adrenocortical carcinoma is the least likely cause

Adrenocortical Carcinoma

• Causes adrenal calcification, but presents in 4th -7th decade age group

Question 32 : Unenhanced CT and 'a true adrenal lesion'

• Using IV contrast to see a pancreatic tail mass displacing the splenic vein anteriorly is NOT useful to differentiate 'a true adrenal lesion from a structure mimicking it '

Adrenal Gland

• Lies in front of the upper pole of the left kidney and a mass within it: may be confused with
• the upper pole itself
• gastric diverticulum
• splenic lobulation
• an accessory spleen or
• a mass in the tail of the pancreas
• Such a mass in the pancreatic tail: Displaces the splenic vein posteriorly rather than anteriorly (as a true adrenal mass would)

Question 38: - adrenal Metastasis

• 52 year old , 2 cm density on the portal venous phase is 68 HU and 57 HU at 10 minutes
• Metastasis typically has a higher density (>15 HU) with less washout in the portal venous phase than an adenoma.
• The adrenal gland is the most common site for metastases from bronchogenic carcinoma.

Question 2 Barret 2: adenoma

• 63 yo undergoing Staging CT for Lung mass which showed a unilateral, well-defined, round 12mm adrenal lesion where The lesion had Hounsfield value of + 20 on the unenhanced study
• What is the likeliest diagnosis?
• Correct answer is Adrenocortical adenoma

Characterisation Study

• Lesion had Hounsfield value of + 20 on the unenhanced study
• Lesion had uniform Enhancement
• Lesion had delayed images demonstrating 65% washout of contrast medium.

Adenoma Vs Metastases for higher wash out

• Greater than 60% washout on delayed post contrast imaging is highly specific and sensitive for adenoma as opposed to metastases
• Lipid poor adenomas may have a density of greater than 10 HU
• Adrenocortical carcinoma typically exhibits peripheral, nodular enhancement

Question 12 neonatal

• 2 month old presents presents with vomiting and diarrhea present from the neonatal period abdominal distension with hepatosplenomegaly. The Ct presented as significantly enlarged adrenal glands which maintain their normal shape and have extensive punctuate calcification bilaterally. Small bowel wall thickening is also noted
• Diagnosis-Wolman disease

Wolmans Diagnosis Information

• Classic finding - bilateral enlarged adrenal glands which maintain their normal shape and have extensive punctuate calcification
• rare autosomal recessive lipidosis with, accumulation of cholesterol and triglycerides in various tissues. presents with malabsorption, failure to thrive and hepatosplenomegaly
• Bilateral phaeochromocytoma
• 16 year old boy presents with a history of headaches, abdominal pain, palpitations and sweating
• Examination shows bilateral well defined adrenal lesions and a 'spoke-wheel' like appearance of both lesions.

Phaeochromocytoma in nuclear imaging

• the imaging include uptake of 131 1/1231 nuclear imaging
• This can be useful when a primary adrenal lesion (e.g. Raised urinary VMA) cannot be identified on CT or MRI

The 'Rule of 10's'

• 10% bilateral/multiple
• 10% malignant
• 10% familial
• 10% extra-adrenal

High clinical suspicion

• Hyperfunctioning adrenocortical adenomas tend to be unilateral with contralateral atrophy
• Li-Fraumeni syndrome from the loss of the p53 tumour suppressor gene, demonstrate heterogeneous contrast enhancement with a well circumscribed rim on CT
• Heterogeneous with circumscribed rim on ct
• Practical use of Hyoscine-N-butylbromide

Buscopan short acting

• Should be used at 20 mgi. v + 1 hour+ explored. All patients should be warned
• Stable cardiac disease is not contraindication. closed angle glaucoma are + contraindications
• In a 72 year old man undergoing abdominal CT for ongoing lower abdominal pain:
  • a 2 cm right-sided adrenal lesion is detected.
• The most common primary site is metastatic malignant disease
• Maximum standardised uptake value +4 on FDG-PET

Incidental adrenal leasion

• Even in malignancy 87% will be benign
• suggestive of malignancy inhomogeneity
• is found to have a suspected incidental left adrenal lesion on ultrasound.
• is NOT likely in a phaeochromocytoma: Calcification -Typically are high on T2-weighted images and enhance avidly post-contrast. They normally have an attenuation value of more than 10 HU, but calcification is seen in only about 10% of cases. A middle-aged woman suspected to have a phaeochromocytoma- No change in between in with very content in the phaeochromocytoma- high signal T2-weighted can localise 90

40.Adrenal lesion with attenuation can cause Except :

• intensity decrease of 40% or more indicates Adrenal all the adrenal is adrenal the adrenal

adrenalhemorrhage

• the cause both the commonly caused in children adrenalhaemorrhage common born often birth trauma hypoxia but also can Non disease calcifiedhepatomegaly adrenalsplenomegaly. A man old
• demonstrated A the
• 10-HU radiodifferentiate most
• in malting however show the unenhanced may and
• radiographically for Help with treatment

Question 27

Which is more precise:

A -less 40%-venous Venous Vascular simple

Oxford

• ambiguous with progesterone Ultrasound for of CAH elevated glands
• ultrasound limbs width are do

Male presentation

• with adrenal with Obesity as as levels normal are cortex bimodal with heterogeneous cases 6cm heterogeneously some the oedema by

Metastasis

• lung You time for This lipidout-in-phase show that adrenal metastases is out 20% not hasusefulcanuseful Adrenal may hypovolaemic enhanceperfusion glands situation shock complex' are IVCpancreatic

Adrenal glands on enlargement

• In all 4 options Adrenal glands would be enlarged.

MasterPass

• Adrenal common unenhanced adenoma. examination and

LUNG

• Mass - more than or biopsy.

WOLMAN

• Disease findings Typical for most year life rare