UNASSIGNED: This study aimed to explore the efficacy of immunocytochemistry in diagnosing abdominopelvic washings (APWs) and evaluate the superiority of cytology combined with immunocytochemistry over cytology alone.
UNASSIGNED: Data on APW cytology and available cell blocks from patients who underwent radical surgery for endometrial cancer between January 2021 and December 2022 were reviewed. Cytology was re-evaluated according to a five-tier system. Immunocytochemistry analysis for targets such as Sry box transcription factor 1(SOX17), Paired box gene 2 (Pax-2) protein, Phosphatase and tensin (PTEN), and β-catenin was performed on each case with non-negative cytology. Mismatch repair (MMR) protein and P53 immunocytochemistry analyses were performed using cell blocks from cases with abnormal MMR or P53 expression in their primary lesion. The accuracies of cytology combined with immunocytochemistry and cytology alone were calculated.
UNASSIGNED: Overall, 126 patients were included in this study, 18 of whom demonstrated non-negative cytology of APW. Cell blocks were successfully prepared for 16 cases. SOX17 positivity was observed in 16 cases, including 1 of serous carcinoma, 1 of clear cell carcinoma, and 14 of endometrioid carcinoma (EC). Loss of Pax-2 and PTEN expression was observed in the APWs of the 14 patients with EC. MMR deficiency was noted in two patients with EC, and P53 mutation was noted in another two patients with EC. Compared with 10 metastatic carcinomas (10/18, 55.56%) diagnosed by cytology alone, 15 malignant APWs (15/18, 83.33%) were confirmed through combination cytology and immunocytochemistry. APWs were more likely to be observed in cases with more than half myometrial invasion than those with no or less than half myometrial invasion (P = 0.0067). The probability of malignant APW occurrence was slightly elevated in cases of EC exhibiting microcystic, elongated, and fragmented(MELF) infiltrative growth (P = 0.039).
UNASSIGNED: SOX17 is a useful Müllerian marker for distinguishing endometrial epithelium in APW. Loss of Pax-2 and PTEN expression offers evidence of metastatic endometrial carcinoma. Furthermore, positive APWs retained molecular features similar to primary lesions. The use of multiple immunocytochemical markers can effectively enhance the diagnostic efficiency of APWs.

Abdominopelvic washings (APW) performed during gynecologic surgeries have become a common specimen evaluated by cytopathologists. Their role in staging of female genital tract tumors has changed significantly since they were first described, and continue to evolve. The ability of these washings to detect microscopic disease, even in the absence of gross disease, warrants the critical role that these washings play in the staging of certain female gynecologic tract tumors, allowing for optimal staging and subsequent treatment of the patient. Irrespective of the underlying pathology, the gamut of cytomorphologic findings that may be observed in APW is extensive, and ranges from benign lesions that may act as mimickers of malignancy, to both common and rare malignancies. This review discusses the changing role of APW in the staging of gynecologic tumors, and highlights the salient cytomorphologic features of these lesions, with emphasis in their correct identification, including cautionary notes to avoid over or misinterpretation. Diagn. Cytopathol. 2016;44:1039-1057. © 2016 Wiley Periodicals, Inc.

Intraperitoneal spread may occur with gynecological epithelial neoplasms, as well as with non-gynecological malignancies, which may result in serosal involvement with or without concomitant effusion. Therefore, washings in patients with abdominopelvic tumors represent important specimens for cytologic examination. They are primarily utilized for staging ovarian cancers, although their role has decreased in staging of endometrial and cervical carcinoma. Abdominopelvic washings can be positive in a variety of pathologic conditions, including benign conditions, borderline neoplastic tumors, locally invasive tumors, or distant metastases. In a subset of cases, washings can be diagnostically challenging due to the presence of co-existing benign cells (e.g., mesothelial hyperplasia, endosalpingiosis, or endometriosis), lesions in which there is only minimal atypia (e.g., serous borderline tumors) or scant atypical cells, and the rarity of specific tumor types (e.g., mesothelioma). Ancillary studies including immunocytochemistry and fluorescence in situ hybridization may be required in difficult cases to resolve the diagnosis. This article provides a comprehensive and contemporary review of abdominopelvic washings in the evaluation of gynecologic and non-gynecologic tumors, including primary peritoneal and mesothelial entities.