Comparative Use of Napsin A and Glypican 3 to Distinguish Endometrial Clear Cell from Serous and Endometrioid Carcinomas. Issue 7 (1st September 2018)

• Record Type: Journal Article
• Authors: Miller, Eirwen M.; Tymon-Rosario, Joan; Sunkara, Jaya; Harmon, Bryan E.; Karabakhtsian, Rouzan G.; Novetsky, Akiva P.
• Is Part Of: International journal of gynecological cancer. Volume 28:Issue 7(2018)
• Page Start: 1318
• Page End: 1324
• Publication Date: 2018-09-01
• Subjects: High-grade endometrial cancer -- Clear cell carcinoma -- Immunohistochemistry -- Napsin A -- Glypican 3; Generative organs, Female -- Cancer -- Periodicals; 616.99465
• DOI: 10.1097/IGC.0000000000001303
• Languages: English
• ISSNs: 1048-891X

Abstract

Abstract : Objective: Diagnosis of endometrial clear cell carcinomas is difficult owing to the low reproducibility of histological cell type in high-grade endometrial cancers. Recently, immunoreactivity for napsin A and glypican 3 has been reported in clear cell cancers. We sought to evaluate the use of napsin A and glypican 3 staining to distinguish clear cell carcinoma from other high-grade endometrial cancers. Methods/Materials: Twenty cases of pure and mixed endometrial clear cell carcinoma were extracted from the 2000–2014 archival material in the Departments of Obstetrics & Gynecology and Pathology at Montefiore Medical Center and compared to serous and grade 3 endometrioid controls. Representative sections were stained with monoclonal antibodies to napsin A and glypican 3. Immunostains were independently reviewed by 2 pathologists to assess frequency and pattern of staining. Charts were reviewed for clinicopathologic and treatment data. Results: Granular cytoplasmic positivity for napsin A was observed in 70% of endometrial clear cell carcinomas; only 25% showed cytoplasmic or membranous glypican 3 positivity. No serous or high-grade endometrioid tumors stained for either marker. No cases of clear cell carcinoma that stained negative for napsin A stained positive for glypican 3. No difference in the immunohistochemical profile was found between pure and mixed clear cell carcinomas and between early- and advanced-stage clear cell carcinomas. Conclusions: Napsin A is a more sensitive marker for endometrial clear cell carcinoma than glypican 3. In histologically ambiguous cases, napsin A and glypican 3 may help distinguish clear cell carcinoma from other high-grade histologies. Further investigation of endometrial clear cell carcinoma is needed to identify additional diagnostic tools for this rare histology. Correlation of a unique immunohistochemical profile and clinical outcomes is necessary.