Phaeochromocytoma and adrenal lesions Flashcards
1
Q
What is a Phaeochromocytoma?
A
Neuroendocrine tumour of the chromaffin cells of the adrenal medulla. Hypertension and hyperglycaemia are often found.
- 10% of cases are bilateral.
- 10% occur in children.
- 11% are malignant (higher when tumour is located outside the adrenal).
- 10% will not be hypertensive.
2
Q
Familial cases are usually linked to the Multiple endocrine neoplasia syndromes (considered under its own heading).
A
- Most tumours are unilateral
- (often right sided) and smaller than 10cm.
3
Q
What are the diagnostic methods used?
A
- Urine analysis of vanillymandelic acid (VMA) is often used (false positives may occur e.g. in patients eating vanilla ice cream!)
- Blood testing for plasma metanephrine levels.
- CT and MRI scanning are both used to localise the lesion.
4
Q
Treatment?
A
- An irreversible alpha adrenoreceptor blocker should be given, although minority may prefer reversible blockade(1).
- Labetolol may be co-administered for cardiac chronotropic control. Isolated beta blockade should not be considered as it will lead to unopposed alpha activity.
5
Q
Surgery?
(IVC = inferior vena cava)
A
- Once medically optimised the phaeochromocytoma should be removed.
- Most adrenalectomies can now be performed using a laparoscopic approach(2).
- The adrenals are highly vascular structures and removal can be complicated by catastrophic haemorrhage in the hands of the inexperienced.
- This is particularly true of right sided resections where the IVC is perilously close.
- Should the IVC be damaged a laparotomy will be necessary and the defect enclosed within a Satinsky style vascular clamp and the defect closed with prolene sutures.
- Attempting to interfere with the IVC using any instruments other than vascular clamps will result in vessel trauma and make a bad situation much worse.
6
Q
What about Incidental adrenal lesions?
A
Adrenal lesions may be identified on CT scanning performed for other reasons(3). Factors suggesting benign disease on CT include(4):
- Size less than 3cm
- Homogeneous texture
- Lipid rich tissue
- Thin wall to lesion