What's this upper-arm mass that won't play ball?

Cooper is a right-handed 14-year-old who presents with a lump on the right upper arm.

Test your clinical know-how by taking the quiz below. If you select the wrong answer, have another go — you can try as many times as you like!


Dr Kate Kelso is a GP and medical editor at Australian Doctor.

  1. Ahmad Shahrukh Raees, et al. A painless lump in the arm. BMJ 2016; 354:i4503