FREQUENCY OF NAPSIN A POSITIVITY IN OVARIAN CLEAR CELL CARCINOMA AND SEROUS CARCINOMA

Napsin A Positivity in Ovarian Clear Cell Carcinoma

Abstract

Objective: To differentiate ovarian clear cell carcinoma and serous carcinoma by expression of Napsin A positivity.
Study Design: Cross-sectional & descriptive study.
Place and Duration of Study: The study was conducted in Shaukat Khannam Memorial cancer hospital from 2016 to 2017.
Material and Methods: A total of n=59 cases of previously diagnosed cases of clear cell carcinoma and high grade serous carcinoma were selected for this study. The slides were reviewed by an expert panel. Napsin A (MRQ-60) Ventana monoclonal antibody was applied to all the cases. Weak to strong membranous staining in more 5% tumor cells was considered positive. 
Results: Mean age of patients in the study was 46.25 ± 11.1 years. There were n=33 (55.9%) cases of serous carcinoma, n=23 (38.9%) cases of clear cell carcinoma and n=3 (5.08%) cases had biphasic morphology. CK7 was applied and showed positive expression in all the cases. Napsin A was found positive in all the cases of clear cell carcinoma as compared to only n=1 (3%) high grade serous carcinomas and none of the mixed tumors. The relationship was considered significant with a p-value of <0.05.
Conclusion: Expression of Napsin A showed a significant difference in high grade serous carcinoma and clear cell carcinoma. Therefore, Napsin A was found a sensitive and specific marker for the diagnosis of ovarian clear cell carcinoma and can reliably differentiated it from high grade serous carcinoma. Current research recommends a study with large sample size to insight the expression of Napsin A and other immunohistochemical stains.