Disorders of adrenal medulla function

Question 1

Explain phaeochromocytoma

Answer 1

-tumour of the enterochromaffin cells of the adrenal medullar

-extra adrenal pheochromocytoma occurs in sympathetic ganglia or organ of Zuckerkandl

-produce catecholamines:
-epinephrine
-norepinephrine
-dopamine

Question 2

Discuss the rule of 10

Answer 2

-10% bilateral
-10% malignant
-10% extra adrenal

Question 3

Explain genetics of phaeochromocytoma

Answer 3

-current estimates predict that upwards of 40% of all phaeochromocytomas are related to an inherited germline mutation

-of the remaining 60% of tumours —> more than 30% are associated with a somatic mutation

Question 4

Explain the gene, inheritance and clinical features of Neurofibromatosis type I

Answer 4

Gene= NF1
Inheritance= AD
Clinical features= Phaechromocytoma, Cafe au lait macules, Axillary and inguinal freckling, Neurofibromas

Question 5

Explain the gene, inheritance and clinical features of Von Hippel- Lindau disease

Answer 5

Gene= VHL
Inheritance= AD
Clinical features = Phaechromocytoma, Hemangioblastomas Renal, pancreatic, epididymal, and broad ligament cysts
Pancreatic neuroendocrine tumours

Question 6

Explain the gene, inheritance and clinical features of Multiple endocrine neoplasia type 2

Answer 6

Gene= RET
Inheritance= AD
Clinical features=

MEN2A:
Phaeochromocytoma
-Medullary thyroid carcinoma
-Hyperparathyroidism

MEN2B:
-Phaeochromocytoma
-Mucocutaneous neuromas
-Ganglioneuromatosis
-Slender body habitus
-Joint laxity
-Skeletal malformations
-multiple paraganglioma
-early onset

Question 7

Explain symptoms of Phaeochromocytoma

Answer 7

gSweating
gHeadache
gTachycardia
gAnxiety
gFever
gParoxysmal hypertension
gConstipation
gAbdominal Pain
gFits
gVisual disturbance
gPallor or Flushing
gPalpitation
g(Hypotension)
gAngor aminii

Question 8

Explain Phaeochromocytoma investigation

Answer 8

-Eisonophilia
-hyperglycaemia
-hypercalcaemia
-raised urinary:
*metanephrines
*catecholamines

Imaging:
-CT
-MRI
-MIBG Scan

Question 9

Explain management of Phaeochromocytoma

Answer 9

-Emergency
-alpha blockade
-non competitive alpha antagonist:
*phenoxybenzamine phentolamine

-competitive antagonist (Doxazosin)
-beta blockade:
-non selective beta blocker (propranolol)

-fluid resuscitation
-surgery