Case Study: March 2012


  • A 45 year old woman presents with a ciliary body mass.
  • This undergoes fine needle aspiration cytology.


  1. What is the differential diagnosis based on the cytology?
  2. The cells were positive for Melan A and negative for cytokeratins. What is the diagnosis?
Click to show answers
  1. The differential includes melanoma, melanocytoma or pigmented adenoma.
  2. The cells have bland nuclei, low N/C ratios and a cytoplasm packed with melanosomes of equal size and distribution. This is a good example of a melanocytoma. These a cytokeratin negative (unlike adenomas of the ciliary body).