Case Study: April 2007


45 year old female.

Previous intraocular / retinal procedure with retinal membrane peel.

Recurrent retinal traction necessitating further retinal membrane peel.

The figures show the recurrent peeled membrane.

The spindle cells in figure 1 are positive for cytokeratins.

Some of the arrowed cells in figure 3 are positive for CD68.

  1. What is the phenotype of the spindle cells in figure 1?


  1. What accounts for the bubbly appearance of the tissue in Figure 2?


  1. What is the diagnosis?


  1. Which cell type would you expect to find more of in the recurrent peeled membrane, compared to the tissue from the initial peel?
Click to show answers

1. The spindle cells are mostly trans-differentiated RPE cells. The retention of cytokeratin is very useful to identify them as altered RPE cells. There are also some similar appearing myofibroblasts and fibroblasts in the tissue.

2. Emulsified silicon oil that is intra- and extracellular in location.

3. Recurrent proliferative vitreoretinopathy in the presence of vitreous substitute (silicon oil).

4. Macrophages +/- giant cells.


An excellent review by Paul Hiscott: Vitreous biopsy pathology: New kid on the block. Current Diagnostic Pathology, 2001, volume 7, p45-55.