Diagnostic Utility of Cytology and Cell Block with Immunohistochemistry in Detection of Peritoneal Metastasis in Gynecological Malignancies.

Abstract

Background: Peritoneal washing (PW) cytology has become a widely accepted procedure for staging of gynecological malignancies.

Aims: To compare conventional cytology, liquid-based cytology (LBC) and cell block in the evaluation of PWs.

Materials and methods: A total of 50 clinically suspected cases of gynecological malignancies were enrolled, which included 41 ovarian neoplasms, eight uterine, and one case of cervical malignancy. The age of the women ranged from 13 to 74 years. The PW samples obtained in all cases were subjected to conventional cytology, LBC, and cell block preparations. Immunohistochemistry (IHC) was applied on cell blocks and analyzed. A comparative evaluation and statistical correlation between the three techniques was performed.

Results: The number of cases reported as positive for malignancy on conventional smear and LBC were 9 (18%) and 11 (22%), respectively. Fifteen (30%) cases were reported as positive for malignancy on cell block after IHC analysis. All three cytological techniques showed a good correlation in diagnosing peritoneal metastasis on evaluation by Cohen's kappa score (≤ 1.00). However, the overall sensitivity, specificity, and diagnostic accuracy of PW cytology was 43.8%, 94.4%, and 62%, respectively, taking histopathology as the gold standard. The most common malignancy which led to peritoneal fluid involvement was high-grade serous carcinoma of the ovary.

Conclusion: The study demonstrates the usefulness of combining the three cytological techniques to diagnose peritoneal metastasis in gynecological malignancies. Cell block with IHC can help in reducing the false-negative cases and further adds to objectivity in ambiguous cases.