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Utility of paired box gene 8 (PAX8) expression in fluid and fine-needle aspiration cytology
An immunohistochemical study of Metastatic ovarian serous carcinoma
Article first published online: 22 JUN 2010
Copyright © 2010 American Cancer Society
Volume 118, Issue 5, pages 298–302, 25 October 2010
How to Cite
McKnight, R., Cohen, C. and Siddiqui, M. T. (2010), Utility of paired box gene 8 (PAX8) expression in fluid and fine-needle aspiration cytology. Cancer Cytopathology, 118: 298–302. doi: 10.1002/cncy.20089
Fax: (404) 712-0714
- Issue published online: 22 JUN 2010
- Article first published online: 22 JUN 2010
- Manuscript Accepted: 14 MAY 2010
- Manuscript Revised: 8 MAY 2010
- Manuscript Received: 14 APR 2010
- ovarian serous carcinoma;
- peritoneal fluid;
- pelvic fluid;
- paired box gene 8 (PAX8);
Metastases from ovarian neoplasms are commonly encountered in peritoneal fluids. In addition, reactive mesothelial cells in effusion specimens can mimic ovarian serous carcinoma, making the diagnosis difficult. Calretinin has been recognized as a reliable immunohistochemical marker for mesothelial cells, whereas WT1 has proven useful in the diagnosis of ovarian serous carcinoma. This can present a diagnostic pitfall in effusion cytology, because mesothelial cells can demonstrate immunoreactivity for WT1. Recently, paired box gene 8 (PAX8) has been used in distinguishing ovarian from mammary carcinoma. To the authors' knowledge, no studies using PAX8 have been performed on peritoneal cytology specimens to date, and its expression in metastatic ovarian serous carcinoma has not been studied.
These markers, along with BerEP4 and MOC-31, were evaluated in cytology cell block preparations from 30 fluid cytology specimens and 11 fine-needle aspiration specimens.
PAX8 was found to be positive in 37 of 41 (90%) ovarian carcinoma cases studied, and was a sensitive (90%) and specific (100%) marker for the detection of metastatic ovarian carcinoma. In addition, calretinin was found to be useful for identifying mesothelial cells in fluid cytology. Furthermore, although PAX8 and WT1 have demonstrated comparable sensitivity (90% and 93%, respectively) in diagnosing metastatic ovarian carcinoma, PAX8 appears to have superior specificity because staining is not observed in mesothelial cells. BerEP4 and MOC-31 were found to have a lower sensitivity and specificity compared with PAX8.
PAX8-positive, calretinin-negative staining appears to be highly specific and sensitive for detecting metastatic ovarian serous carcinoma in cytologic preparations and can be useful in distinguishing it from mesothelial cells in fluid cytology. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.