Case Study: September 2013


  • A 10 year old African male presents with a cream nodule at the lateral bulbar conjunctiva, towards the lateral canthus, of 6 months duration. The lesion is increasing in size.
  • The lesion is excised and sent of histology.
  • See figures.


  1. What does Fig 1 show?
  2. What does Fig 2 show?
  3. Which immunohistochemical stain has been performed in Fig 3 and what does it illustrate?
  4. What is the diagnosis?
Click to show answers
  1. At this scanning power, there are light and dark zones on the H and E, with lymphocytes predominating in the dark zones.
  2. Fig 2 shows histiocyte-type cells, plasma cells and lymphocytes.
  3. This is an S100 stain. The histiocyte type cells show emperipolesis, better than that seen in Fig 2.
  4. This is conjunctival Rosai-Dorfman disease.