A 55-year-old man presents with episodic hypertension (BP reaching 200/120 mmHg), headache, palpitations, and diaphoresis. 24-hour urine shows elevated metanephrines and normetanephrines. CT confirms a 4 cm right adrenal mass. The 'Rule of 10s' for phaeochromocytoma includes which of the following as part of its description?
- A 10% bilateral, 10% malignant, 10% extra-adrenal, 10% familial, 10% in children ✓
- B 10% occur in MEN1, 10% are bilateral, 10% are benign
- C 10% cause only hypertension without other symptoms, 10% have calcifications
- D All phaeochromocytomas are solitary in 90% of cases
Correct answer: A. 10% bilateral, 10% malignant, 10% extra-adrenal, 10% familial, 10% in children
Explanation
The classic 'Rule of 10s' for phaeochromocytoma states: 10% bilateral, 10% malignant, 10% extra-adrenal (paraganglioma), 10% familial (MEN2A, MEN2B, VHL, NF1, SDH mutations), and 10% occur in children. However, more recent data suggests these figures are underestimates — with modern genetic testing, up to 25–40% have a germline mutation. Pre-operative preparation requires alpha-blockade (phenoxybenzamine) for 10–14 days before laparoscopic adrenalectomy, followed by beta-blockade.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
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