The mnemonic
Rule of 80
What each word stands for
- 80About 80 percent arise in the parotid
- 80About 80 percent of parotid tumours are benign
- 80About 80 percent of benign ones are pleomorphic adenoma
Why it matters clinically
Gives the likely diagnosis of a parotid lump.
Where it stops being reliable
Approximate figures; the submandibular gland has a higher malignant share.
Teaching aid, still awaiting independent review. Confirm facts in a standard source.