This is the histology of a skin lesion removed from a boy.

• What is the most likely diagnosis and why?


Answer
Juvenile xanthogranuloma. Presence of multiple
Touton's cells ie. ring of nuclei separating the 
central pink cytoplasm from the peripheral clear
cytoplasm. Refer to the bottom picture for a magnified view.

 
How can this condition affect the eye?
a
Answer
The lesion may appear in the iris causing spontaneous hyphaema.