Initial pharmacological treatment permits optimal surgical interventions.
- medical
- objective - to control the adverse effects of circulating catecholamines until definitive surgery
- alpha blockers (phenoxybenzamine, metyrosine, prazosin) to control hypertension. Once alpha blockers are used, if tachycardia is present
- beta blockers (oral propranolol) - prevents catecholamine-induced arrhythmias
- phentolamine or nitroprusside - hypertensive crises during and before surgery
- hypotension is a post-op complication - prevented with adequate volume expansion preoperatively.
The tumour is localised using the following imaging methods:
- CT scan - which can detect tumours greater than 1 cm in diameter
- 131 I-meta-iodobenzylguanidine (MIBG) scintigraphy:
- more sensitive than CT
- MIBG is specifically concentrated in adrenergic cells and is useful for assessing metastases
Surgery is curative in 75% of cases
- for adrenal phaeochromocytomas
- adrenalectomy following pre-op stabilization
- laparoscopic adrenolectomy
- transabdominal approach
- excessive handling of the tumour peroperatively should be avoided as this may release large amounts of catecholamine into the circulation resulting in severe, acute hypertension
- vasodilators such as sodium nitroprusside, and intra-venous alpha- and beta-blockers should be available during surgery in the event of a hypertensive crisis
- operative mortality is at least 3%.
When surgery is not possible, consider treatment with:
- phenoxybenzamine and propranolol
- alpha-methyl-p-tyrosine - inhibits the hydroxylation of tyrosine to dopa and so, reduces synthesis of adrenaline and noradrenaline
combination chemotherapy if malignant:
- cyclophosphamide
- vincristine
- dacarbazine