A 3-year-old Thai boy from Chonburi Province came with a lump on the back of the right ear for 2 weeks.

Abstract

A 3-year-old Thai boy from Chonburi Province came with a lump on the back of the right ear for 2 weeks.

Physical examination found a round mass 1.5 cm in diameter at the posterior auricular area, smooth surface, not tender, not movable

The patient has been mass excision done.

Intraoperative found soft consistency mass, 2 cm in diameter, skull defect beneath the mass

The skull films and the histo-pathological sections were shown in the picture

Question

1. Please describe what you find from skull films
2. What is a diagnosis?
3. Which the special stains might helps in the diagnosis?

 Woranart Ratanakorn, MD                                                                                                                           woranartr@hotmail.com