Immunohistochemistry in ocular carcinomas

Background:  The distinction between ocular sebaceous carcinoma, poorly differentiated ocular squamous cell carcinoma and ocular basal cell carcinoma can be challenging. An appropriate immunohistochemical panel may help to differentiate these lesions.Methods:  To determine the distribution and use of several immunostains in these specimens, formalin‐fixed, paraffin‐embedded tissue from several of each was studied using an immunohistochemical technique.Results:  Positive staining for cytokeratin (CK)7 was seen in 100% of sebaceous carcinomas, 77.8% of basal cell carcinomas and 67.7% of squamous cell carcinomas. One hundred percent of sebaceous and basal cell carcinomas were positive for cytokeratin CAM 5.2, while only 83.3% of squamous cell carcinomas were positive. Using epithelial membrane antigen (EMA), 100% of squamous cell carcinomas and 80% of sebaceous carcinomas were positive, while basal cell carcinomas were uniformly negative. One hundred percent of basal cell carcinomas and 80% of sebaceous carcinomas were positive for Ber‐EP4, while all squamous cell carcinomas were negative. Finally, 77.8%, 20% and 16.7% of basal cell carcinomas, sebaceous carcinomas and squamous cell carcinomas showed immunoreactivity for the androgen receptor.Conclusion:  An EMA positive, Ber‐EP4 positive immunophenotype supports sebaceous carcinoma, EMA positive, Ber‐EP4 negative result supports squamous cell carcinoma and an EMA negative, Ber‐EP4 positive result supports basal cell carcinoma.