387- Phaeochromocytoma Flashcards
Phaeochromocytomas and paragangliomas are __ derived from __
Phaeochromocytoma: __
Paragangliomas: __
The tumours arise __ or inherited as features
The naming reflects formerly used staining technique __
Catecholamine-producing tumours from sympathetic or parasympathetic nervous system
Phaeochromocytoma: adrenal gland tumour
Paragangliomas: tumours from other sites (skull base, neck)
Arise sporadically or inherited as features*
*discussed in another flashcard
Chromaffin oxidation of catecholamines staining black colour
What are the inherited conditions that are associated with phaeochromocytoma?
- Von-Hippel-Lundau
- Neurofibromatosis
- Multiple endocrine neoplasia type 2 (MEN 2)
Classical triad of phaeochromocytoma: __, __, __
Palpitation
Headache
Profuse sweating
How do patients with phaeochromocytoma present?
- May be asymptomatic for years
- Classical triad of phaeochromocytoma
- Paroxysmal hypertension and headache
- Sustained hypertension
- Catecholamine crisis
Phaeochromocytoma causes __ hypertension and headache because of hormonal release at widely divergent intervals
Patients will feel __, __, __, __, usually lasting __, at varying times and intervals.
Symptoms may be precipitated by (6)
Medications that precipitates phaeochromocytoma (3)
Paroxysmal symptoms
Anxious, tachycardia, palpitations, pale
Lasting < 1 hour
Precipitating factors: stressors
- Surgery
- Positional changes
- Exercise
- Pregnancy
- Urination
- Medication
Medications: TCA, opiates, metoclopramide
What are the clinical features of phaeochromocytoma?
-
Rule of 10 in Phaeochromocytoma
10% bilateral or multiple
10% malignant (or metastasize)
10% in children
10% extrarenal (up to 30%)
10% familial (associated with MEN) (up to 30-40%)
10% no hypertension
10% calcified
10% incidentally discovered
10% recurrence
10% presents with stroke
Definitive investigations for phaeochromocytoma
- Urine and plasma catecholamines and metanephrines
- 3x higher than upper limit of normal
- False positives may occur due to stress response or drugs
Drug factors:
- Withdrawal of levodopa
- Use of sympathomimetics, diuretics, TCA, alpha and beta blockers
1A. Clonidine suppression test - TRO false positive
- Measures plasma normetanephrine 3 hours after clonidine 300mcg
Low sensitivity tests: phentolamine, glucagon provocation
- CT or MRI adrenal glands
- 5-10% of adrenal incidentalomas aree phaeo - MIBG scintigraphy
- Somatostatin receptor scintigraphy
Most sensitive and specific
5. Fluoro-DOPA PET CT
6. Gallium-DOTATOC PET CT
- Offer genetic testing to patients
Histology of phaeochromocytoma
“Zellballen” pattern of nests of neuroendocrine chief cells with peripheral glial-like subtentacular cells
Stain positive for chromogranin and synaptophysin in chief cells, S-100 in sustentacular cells
Management of phaeochromocytoma
A. Control of paroxysmal hypertension
1. Alpha adrenergic antagonist
- Phenoxybenzamine 0.5-4mg/kg
- Prazosin
- IV phentolamine
- Vasodilators
- Nitroglycerine
- Sodium nitroprusside (esp in phaeo crisis) - Beta antagonist
- Non-cardioselective: propranolol 10mg TDS - Others (less effective)
- Calcium channel antagonist, ACE inhibitors
B. Surgical removal
Laparoscopic or open
- Check pre and post catecholamine
- Check pre and post ACTH to exclude cortisol deficiency with bilateral adrenal cortex removal
C. Metastatic phaeochromocytoma
- Tumour mass reduction
- Alpha antagonist
- Chemotherapy
- Radiotherapy
- Palliative in end stage disease
5-year survival rates: 30-60%
Phaeochromocytoma in MEN 2A and MEN 2B
MEN 2A
- Medullary thyroid carcinoma
- Phaeochromocytoma
- Hyperparathyroidism
MEN 2B
- Medullary thyroid carcinoma
- Phaeochromocytoma
- Mucosal neuromas
- Marfanoid habitus
All MEN 2 has MTC, but only 50% has phaeochromocytoma
Phaeochromocytoma in VHL
Retinal and cerebellar haemangioblastomas
Clear cell renal carcinoma
Pancreatic neuroendocrine tumour
Endolymphatic sac tumours of inner ear
Cystadenomas of epididymis and broad ligament
Multiple pancreatic and renal cysts
Phaeochromocytoma (20-30%)
Phaeochromocytoma in NF1
Multiple neurofibromas
Cafe au lait spots
Axillary freckling of skin
Lisch nodules of iris
Phaeochromocytoma in 1%
