Endocrine - Phaeochromocytoma Flashcards
(105 cards)
1
Q
What is a catecholamine-secreting tumor that arises from chromaffin cells?
A
Phaeochromocytoma
Phaeochromocytoma is derived from neural crest origin.
2
Q
What does ‘Pheo’ and ‘chromo’ refer to?
A
Pheo = dusky, chromo = color
These terms describe the appearance of the tumor.
3
Q
What additional tumors are often referred to as pheochromocytomas?
A
Extraadrenal catecholamine-secreting paragangliomas
This is a broader classification that includes tumors outside the adrenal gland.
4
Q
What percentage of pheochromocytomas are adrenal?
A
90%
Most pheochromocytomas arise from the adrenal glands.
5
Q
What percentage of pheochromocytomas are extra-adrenal?
A
10%
These are classified as paragangliomas.
6
Q
Where do most extra-adrenal pheochromocytomas occur?
A
In the abdomen
This is related to the embryological origin from neural crest tissue.
7
Q
What is the organ of Zuckerkandl?
A
Chromaffin tissue situated along the aorta
It is a key site for extra-adrenal chromaffin cells.
8
Q
Fill in the blank: Phaeochromocytomas arise from _______.
A
Chromaffin cells
These cells are derived from neural crest tissue.
9
Q
What is the incidence rate of pheochromocytomas?
A
Rare 1-2 per million
Majority are sporadic but still have a strong association to germ-line mutations.
10
Q
What is MEN Syndrome - Type 2 associated with?
A
RET onco-Gene
It includes Medullary thyroid Ca, Hyperparathyroidism, ganglioneuroma, and Megacolon.
11
Q
What percentage of patients with MEN 2 develop Phaeo?
A
1/3 of pts
Phaeo refers to pheochromocytoma.
12
Q
What gene is associated with Von-Hippel-Lindau syndrome?
A
VHL - tumour suppressor gene
Associated features include Haemangioblastoma, Renal Cell cancer, and cysts of kidneys, testis, and pancreas.
13
Q
What is the occurrence rate of Phaeo in Von-Hippel-Lindau syndrome?
A
1/3
This indicates that one-third of patients may develop pheochromocytoma.
14
Q
What gene is linked to Neurofibromatosis Type 1?
A
NF1 gene
Common features include Café-au-lait spots, skin-fold freckling, and Iris Hamatomas.
15
Q
What mutations are associated with multiple paragangliomas?
A
Succinate Dehydrogenase mutations
These mutations are linked to the SDH gene.
16
Q
Fill in the blank: MEN Syndrome - Type 2 is associated with the _______ gene.
A
RET onco-Gene
17
Q
True or False: The majority of Phaeochromocytomas are hereditary.
A
False
Majority are sporadic.
18
Q
What are the associated features of Neurofibromatosis Type 1?
A
Café-au-lait spots, skin-fold freckling, Iris Hamatomas
These features help in diagnosing the condition.
19
Q
What types of cancers are associated with Von-Hippel-Lindau syndrome?
A
Haemangioblastoma, Renal Cell cancer
This syndrome also includes cysts in kidneys, testis, and pancreas.
20
Q
List four conditions associated with increased risk of phaeochromocytoma
A
MEN II
Von hippel Lindau
Neurofibromatosis type 1
Succinate dehydrogenase mutations
21
Q
When in particular should you consider Men II, VHL. SDH mutation or NF 1 mutations in patients with phaeos?
What should you do in these cases?
A
Raised supicion in younger patients presents with this tumour
Examine for associated features
Consider genetic testing
22
Q
What are the clinical hallmarks/features of phaeochromocytomas?
A
paroxysmal release of excessive amounts of catecholamine.
Patient is often well in between attacks
Postural changes, affect symptoms
Anxiety can make symptoms worse
23
Q
What acute/emergency can phaeochromocytomas precipitate?
What are the symptoms of this?
What can induce this state?
A
Adrenegic Response
Phaeo Crisis= massive Surg of catecholamines
Classic TIRAD
Palpitations/Tachycardia
Headaches + HTN (90% - chronic or paroxsymal
Episodic sweating
Can be induced by:Trauma/handling/haemorrhage
24
Q
What are the effects of long term exposure to increased catecholamines
A
Hyperglycaemia, Diabetes
Lead to: arrhythmia/heart failure/MODS/strokes and Sudden death/
25
What is the origin of pheochromocytoma?
Chromaffin cells of the adrenal medulla
## Footnote
Pheochromocytomas arise from specialized cells that produce catecholamines.
26
What does the name 'pheochromocytoma' refer to?
Stain brown when treated with chromium salts
## Footnote
The name derives from the staining characteristics of the tumor.
27
Which hormone is mainly secreted by adrenal pheochromocytomas?
Adrenaline
## Footnote
Extra-adrenal sites primarily secrete nor-adrenaline.
28
What is the '10% Tumour' concept in relation to pheochromocytoma?
10% bilateral, 10% extra-adrenal, 10% familial, 10% malignant, 10% asymptomatic
## Footnote
This concept outlines the common characteristics and statistics associated with pheochromocytomas.
29
Where can extra-adrenal pheochromocytomas be found?
Along para-aortic sympathetic chain, wall of bladder, neck, mediastinum
## Footnote
Less common sites include the intraatrial cardiac septum, spermatic cord, vagina, scrotum, and sacrococcygeal region.
30
What are paragangliomas and where do they arise from?
Arise from PSNS tissue in head & neck
## Footnote
They do not hypersecrete catecholamines.
31
What is the familial occurrence rate of pheochromocytoma according to recent studies?
More like 30%
## Footnote
Recent studies have improved our understanding of genetics related to pheochromocytomas.
32
What is the significance of histological differentiation in pheochromocytomas?
Relies on operative findings of local invasion or metastasis
## Footnote
This helps differentiate between benign and malignant tumors.
33
What percentage of SDHB+ pheochromocytomas are malignant?
37.5%
## Footnote
This statistic was noted in a study published in ANZ 2009.
34
Does the size of a pheochromocytoma correlate with the risk of malignancy?
No
## Footnote
Unlike adrenocortical tumors, size does not indicate the risk of malignancy.
35
How do malignant pheochromocytomas typically spread?
Hematogenously
## Footnote
Lymphatic spread is also possible but less common.
36
What percentage of pheochromocytoma cases are asymptomatic?
10%
## Footnote
These cases are clinically silent and may go undetected.
37
What is the key question in biochemical diagnosis for catecholamines?
Is there abnormally high levels of catecholamines?
## Footnote
High levels can indicate conditions such as pheochromocytoma.
38
Why is testing the levels of adrenal and noradrenal not preferred?
It has a high false-positive rate affected by timing, stress, and medications.
## Footnote
This means results can be misleading if not conducted under optimal conditions.
39
What is the gold standard for screening tests in biochemical diagnosis?
Plasma free Metanephrines or 24-hour Urine fractionated metanephrines.
## Footnote
These tests measure the breakdown products of catecholamines and provide a more reliable estimate of tumor bulk.
40
Which is better for diagnosing catecholamine issues, urine or blood tests?
Similar sensitivity and specificity; choice depends on patient factors and lab expertise.
## Footnote
Both urine and blood tests can effectively detect catecholamine levels.
41
What is the purpose of the Clonidine suppression test?
It is a confirmatory test to rule out false positives.
## Footnote
This test helps to confirm the presence of pheochromocytoma.
42
What is Clonidine and its role in diagnosing catecholamine release?
Clonidine is a centrally acting a2 agonist that normally suppresses catecholamine release from neurons but not from pheochromocytoma.
## Footnote
This characteristic is utilized to differentiate between normal catecholamine release and that from a tumor.
43
What dosage of Clonidine is used in the suppression test?
0.3 mg po.
## Footnote
This oral dosage is administered to evaluate plasma catecholamine levels before and after the dose.
44
What happens to plasma catecholamine levels in patients without pheochromocytoma after Clonidine administration?
The levels decrease.
## Footnote
This decrease indicates normal feedback mechanisms are functioning.
45
What imaging technique is good for anatomical location?
CT
## Footnote
CT provides detailed anatomical information, making it useful for locating structures within the body.
46
What is the typical Hounsfield Unit (HU) range for soft tissue density in CT?
40-50
## Footnote
This range indicates soft tissue characteristics in CT imaging.
47
What CT features may suggest the presence of cancer?
Heterogeneous appearance, large size, or hemorrhaging
## Footnote
These features can mimic cancerous lesions during imaging.
48
Which imaging technique is better for soft tissue characterisation?
MRI
## Footnote
MRI excels in differentiating between various soft tissue types.
49
When are functional studies indicated?
When the diagnosis is not clear or there is a risk of benign adenoma co-existing with a functional micro or occult phaeo
## Footnote
Functional studies help clarify ambiguous cases.
50
What is the sensitivity and specificity of I123 MIBG Scintigraphy?
90%
## Footnote
This imaging technique is highly effective for detecting certain adrenal conditions.
51
What is MIBG in I123 MIBG Scintigraphy?
A structural analogue of NAd not taken up by normal adrenal medullary tissue
## Footnote
MIBG helps identify specific adrenal pathologies.
52
What are useful applications of I123 MIBG Scintigraphy?
* Extra-adrenal phaeo
* Recurrences
* Check for multifocal or metastatic disease
## Footnote
These applications enhance diagnostic accuracy in certain cases.
53
What imaging technique is indicated for functional studies aside from MIBG?
Fluorodopamine with PET
## Footnote
PET imaging can provide functional information about adrenal tumors.
54
True or False: Resource constraints and regional variability impact the availability of imaging techniques.
True
## Footnote
Access to certain imaging modalities can vary based on location and available resources.
55
What is the importance of medical management in phaeochromocytoma?
Medical management is just as important as ultimate surgical management
## Footnote
Medical management focuses on opposing the life-threatening effects of excessive adrenergic stimulation from catecholamines.
56
What is the goal of preoperative medical management for phaeochromocytoma?
To oppose life-threatening effects of excessive adrenergic stimulation
## Footnote
This includes reducing blood pressure and heart rate to minimize the risk of massive surges.
57
What can occur if beta-blockade is unopposed in phaeochromocytoma?
It can lead to severe alpha adrenergic response and death
## Footnote
Unopposed beta-blockade results in a dangerous imbalance in adrenergic stimulation.
58
What is the first line treatment for alpha blockade in phaeochromocytoma?
Phenoxybenzamine
## Footnote
The dose should be uptitrated until hypertension resolves, starting approximately 10 days before surgery.
59
What are some alternatives to phenoxybenzamine for alpha blockade?
* Doxazosin
* Urapidil
## Footnote
These alternatives can be used if phenoxybenzamine is not suitable.
60
What is the purpose of beta blockade in phaeochromocytoma management?
To counteract tachycardia and arrhythmia
## Footnote
Beta-blockers help manage heart rate and rhythm in patients.
61
What role does IV hydration play in the management of phaeochromocytoma?
Fluid loading in anticipation of fluid shifts post-op
## Footnote
It is crucial for repletion when initiating anti-hypertensives and for preventing hypotension after tumor removal.
62
What monitoring is required during the intraoperative phase of phaeochromocytoma surgery?
Invasive BP monitoring
## Footnote
This includes arterial lines and central venous lines due to risks of rapid changes in blood pressure.
63
What medications may be administered intraoperatively for phaeochromocytoma?
* Short-acting vasodilators
* Calcium channel blockers
* Beta-blockers
## Footnote
These medications help manage intraoperative blood pressure and heart rate.
64
What happens to catecholamine levels postoperatively after tumor removal?
There is a significant fall in catecholamine levels
## Footnote
This can lead to a potential significant drop in blood pressure.
65
What care is recommended postoperatively for patients who have undergone phaeochromocytoma surgery?
Significant volume replacement and inotropes
## Footnote
High Dependency Unit (HDU) care is recommended due to the risk of hypotension.
66
What metabolic changes should be monitored postoperatively in phaeochromocytoma patients?
Blood sugars for hypoglycemia
## Footnote
There is a loss of lipolysis and glycogen synthesis that needs monitoring.
67
What is the purpose of pre-operative optimization in surgical management?
To improve hypertension and cardiac function
68
What types of blockade are recommended for pre-operative optimization?
Alpha blockade and beta blockade
69
What is the recommended pre-operative hydration strategy?
IV fluid hydration and electrolyte replacement
70
How long should patients receive α and β blockade before surgery?
A few weeks
71
What surgical option is recommended for adrenal tumors less than 6 cm?
Laparoscopic adrenalectomy
72
What surgical approach is preferred for large adrenal tumors or those with higher risk of malignancy?
Open adrenalectomy
73
What is the surgical management for bilateral adrenal tumors in hereditary cases?
Bilateral adrenalectomy
74
What is a disadvantage of bilateral adrenalectomy?
Life-long steroid replacement
75
What is the approach for benign adrenal tumors in certain genetic conditions?
Subtotal cortical sparing adrenalectomy
76
What is the risk associated with subtotal cortical sparing adrenalectomy?
Risk of recurrent tumor in remnant
77
What should be done if the tumor is unresectable?
Debulk, provide radiotherapy, and α-blockade
78
What is the typical risk of malignancy for patients with MEN2, VHL, and SDHD germ-line mutations?
Less than 5%
79
What is the mortality rate for undiagnosed or pre-operatively managed phaeochromocytoma?
50%
## Footnote
This high mortality rate emphasizes the importance of careful management during surgery.
80
What should you do if you find an undiagnosed phaeochromocytoma during a laparotomy?
STOP operation
## Footnote
Immediate cessation of the operation is crucial to prevent complications.
81
When should you treat the primary pathology if an undiagnosed phaeochromocytoma is found?
If urgent or life-threatening
## Footnote
Only focus on the primary issue if it poses an immediate risk to the patient's life.
82
What should you avoid doing with the tumor during surgery?
Don’t handle the tumor if possible
## Footnote
Handling the tumor can provoke a hypertensive crisis.
83
What medical management should be initiated after finding an undiagnosed phaeochromocytoma?
Start patient on appropriate medical management and blockade
## Footnote
This helps to stabilize the patient before further intervention.
84
What is the recommended follow-up for patients with malignant adrenal phaeochromocytoma?
Surveillance is mandatory
## Footnote
This includes monitoring for distant metastases that may not be apparent immediately.
85
How often should urine be rescreened post-operatively for patients with a history of phaeochromocytoma?
1-3 months post-operatively, then annually
## Footnote
Regular rescreening helps in early detection of any recurrence.
86
What screening is recommended for first-degree relatives of patients with phaeochromocytoma?
Screen urine and genetic testing in <50 y.o.
## Footnote
Early detection in relatives can lead to timely intervention.
87
True or False: The diagnosis of malignant adrenal phaeochromocytoma is often apparent at the time of initial surgery.
False
## Footnote
Malignancy may not be evident until distant metastases are found during follow-up.
88
What is the mortality rate for undiagnosed or pre-operatively managed phaeochromocytoma?
50%
## Footnote
This high mortality rate emphasizes the importance of careful management during surgery.
89
What should you do if you find an undiagnosed phaeochromocytoma during a laparotomy?
STOP operation
## Footnote
Immediate cessation of the operation is crucial to prevent complications.
90
When should you treat the primary pathology if an undiagnosed phaeochromocytoma is found?
If urgent or life-threatening
## Footnote
Only focus on the primary issue if it poses an immediate risk to the patient's life.
91
What should you avoid doing with the tumor during surgery?
Don’t handle the tumor if possible
## Footnote
Handling the tumor can provoke a hypertensive crisis.
92
What medical management should be initiated after finding an undiagnosed phaeochromocytoma?
Start patient on appropriate medical management and blockade
## Footnote
This helps to stabilize the patient before further intervention.
93
What is the recommended follow-up for patients with malignant adrenal phaeochromocytoma?
Surveillance is mandatory
## Footnote
This includes monitoring for distant metastases that may not be apparent immediately.
94
How often should urine be rescreened post-operatively for patients with a history of phaeochromocytoma?
1-3 months post-operatively, then annually
## Footnote
Regular rescreening helps in early detection of any recurrence.
95
What screening is recommended for first-degree relatives of patients with phaeochromocytoma?
Screen urine and genetic testing in <50 y.o.
## Footnote
Early detection in relatives can lead to timely intervention.
96
True or False: The diagnosis of malignant adrenal phaeochromocytoma is often apparent at the time of initial surgery.
False
## Footnote
Malignancy may not be evident until distant metastases are found during follow-up.
97
What should be avoided during the management of pheochromocytoma in pregnancy?
Spontaneous labor and delivery
## Footnote
High risk of maternal and foetal death
98
What are the diagnostic tests for pheochromocytoma?
24hrs Urine or plasma metanephrines
## Footnote
These tests help in confirming the diagnosis.
99
What is the imaging test of choice for pheochromocytoma?
MRI without gadolinium
## Footnote
This imaging modality is preferred to avoid risks associated with gadolinium.
100
What medical treatments are used for pheochromocytoma?
± b-blockers (phenoxybenzamine and propranolol)
## Footnote
These medications help manage symptoms related to catecholamine excess.
101
What is the management strategy for pheochromocytoma in the 1st trimester of pregnancy?
Medicate & let patient progress with pregnancy (then operation later or C-section)
## Footnote
Surgical intervention is delayed until after the first trimester.
102
What is the management strategy for pheochromocytoma in the 2nd trimester (up to 25 weeks)?
Medicate + operate on pheochromocytoma
## Footnote
Surgical intervention is feasible within this timeframe.
103
What is the limitation for surgical intervention after 25 weeks of pregnancy?
The uterine size is too large for laparoscopic adrenalectomy
## Footnote
Open adrenalectomy may be considered if necessary.
104
What is the management strategy for pheochromocytoma in the 3rd trimester?
Medicate + do C-section & ideally pheochromocytoma operation at the same time
## Footnote
C-section is typically performed at 30 weeks.
105
What is the natural history of labor in patients with pheochromocytoma?
High fetal & maternal mortality (≈50%)
## Footnote
The risk is significantly elevated during labor.
