Miller EM, et al. - Researchers evaluated the use of napsin A and glypican 3 staining in distinguishing clear cell carcinoma from other high-grade endometrial cancers. From the 2000–2014 archival material in the Departments of Obstetrics & Gynecology and Pathology at Montefiore Medical Center, they extracted 20 cases of pure and mixed endometrial clear cell carcinoma and compared these to serous and grade 3 endometrioid controls. They stained representative sections with monoclonal antibodies to napsin A and glypican 3. Findings suggest that for endometrial clear cell carcinoma, napsin A is a more sensitive marker than glypican 3. They also suggest a possible potential of napsin A and glypican 3 in distinguishing clear cell carcinoma from other high-grade histologies in histologically ambiguous cases.