positive peritoneal washings are considered to be an important factor in management of patients with gynecological malignancies . patients with positive peritoneal washings have been found to have worse prognosis than patients without malignant cells in cytology . positive peritoneal washing in endometrial cancer is associated with an increased risk of recurrence and poor survival . factors that can lead to false negative peritoneal cytology include inadequate volume of peritoneal fluid examined , obscuration of the tumor cells by florid mesothelial reaction , blood , excessive dilution of malignant cells , or small foci of peritoneal metastasis such that the tumor cells are not easily identified . conventional smear may display cell clumping in one corner of the smear , obscuring of cells by mucus , haemorrhage , inflammatory cells , and debris along with multilayering of cells which will hamper cytological interpretation of the smear . liquid - based cytology ( lbc ) uses the principle of cell filtration ( thinprep ) or cell enrichment ( surepath ) . consequently , the smears are homogenously stained , circular smears of 22 mm diameter in thinprep and 13 mm diameter in surepath , which contain 5070000 well - preserved cells per smear . the cells are uniformly distributed throughout the circular smear , which is devoid of background debris and obscuring by red blood cells ( rbcs ) or inflammatory cells . because of uniform staining and absence of background debris , the nuclear morphology is clear on lbc smear . thus , lbc preparations can overcome the shortcomings of conventional smears to a large extent and improve the diagnostic accuracy . a similar study in the english literature has explored the efficacy of thinprep lbc technique . the aim of the present study was to evaluate gynecological cancers causing positive peritoneal cytology and to evaluate diagnostic accuracy of lbc using bd surepath lbc technique in peritoneal cytology . an audit of peritoneal fluid / washing / lavage ( january 2012 to july 2013 ) was performed with identification of corresponding gynecologic specimens . the samples were centrifuged and the smears were prepared from the sediment using a conventional technique ; the samples were then processed as per the manufacturer 's instructions for surepath lbc technique . however , suspicious cases at the time of initial reporting were reported in the light of corresponding histopathologic diagnosis to categorize all cytology samples as  positive  or ( it is the standard practice in our department that smears with equivocal features on cytology are reported after examining the corresponding histopathological sections ) . all the positive peritoneal wash samples were reviewed by two cytopathologists ( rt , ng ) to analyze cytological features in various gynecological malignancies and to study the difference in cytomorphology in conventional versus surepath lbc technique . peritoneal fluid / washings comprised a total of 393 samples out of 12971 samples of exfoliative cytology ( excluding cervical pap samples ) received in the department during the study period . age range for ovarian epithelial neoplasms ( 1573 ; mean 46.6 years ) , germ cell tumors ( 1456 ; mean 27 years ) , sex - cord stromal tumors ( 1970 ; mean 48 years ) , and uterine malignancies ( 2685 ; mean 57 years ) was noted . a total of 83/393 ( 21.1% ) were positive and 310/393 ( 78.9% ) were negative for malignancy on peritoneal cytology . out of the 393 samples of peritoneal washes , corresponding histology was available in 352 cases only . rest of the cases either did not undergo surgery or were lost to follow - up . out of 83 positive peritoneal washings , 69 samples had ovarian malignancies and 5 had uterine causes . no record of histopathology of the remaining 9 cases with positive peritoneal cytology was available . out of a total of 84 histopathologically diagnosed ovarian serous carcinoma cases , 55 ( 65.5% ) cases had positive peritoneal cytology [ figure 1a and b ] . only 3 cases had a few clusters in conventional smears and the diagnosis was based mainly on lbc samples . tumor cells were seen in peritoneal cytology in 1/8 ( 12.5% ) cases of borderline serous tumor ( atypical proliferative serous tumor ) with a few tiny papillaroid clusters of tumor cells . this case four out of 9 cases ( 44.4% ) of mucinous adenocarcinoma were positive [ figure 1c and d ] with clusters as well as scattered tumor cells with mild nuclear atypia embedded in abundant mucinous material . chicken - wire type of capillary network associated with mucin was also appreciated in 3 out of 4 cases . lbc helped to identify malignant cells in 2 cases , which were darkly stained and embedded in thick mucin in conventional smears . pseudomyxoma peritonei was seen in two cases of ovarian mucinous cystadenoma with mucinous neoplasm involving the appendix . the tumor was present in ovary as well as the appendix ; hence , ovarian involvement was not secondary . thick mucinous material along with benign mesothelial cells were seen in these cases . mucinous material was seen metachromatically staining in conventional smears ; however , the same was also represented as thick greenish mucin pools in lbc smears . three out of 4 ( 75% ) cases of dysgerminoma , squamous cell carcinoma in teratoma ( n = 1 ) [ figure 2a and b ] , 2/4 ( 50% ) yolk sac tumor , and 1/13 ( 7.7% ) granulosa cell tumor had positive peritoneal cytology . cytology samples revealed dispersed population of intermediate - sized tumor cells with high n / c ratio , coarse chromatin , prominent nucleoli , and scanty vacuolated cytoplasm in cases of dysgerminoma . these were better seen in conventional mgg smears as compared to lbc samples due to even smaller size and intense staining in lbc smear . the case of squamous cell carcinoma showed tumor cells having squamoid differentiation and marked variation in size and shapes of the tumor cells . cases of yolk sac tumor showed obviously malignant cell clusters admixed with florid mesothelial cell proliferation . the main clue to diagnosis of a germ cell tumor in fluid cytology was round - to - oval tumor cells with very prominent nucleoli and vacuolated cytoplasm . the case of granulosa cell tumor revealed classic morphology with dispersed population of round - to - angulated tumor cells and a few tumor cells arranged in acinar - like arrangement around pink staining bodies . the cases of dysgerminoma , yolk sac tumor , and granulosa cell tumor were initially reported as  positive for malignancy  on cytology . positive peritoneal washing in ovarian serous carcinoma ( a ) cps ( mgg 40 ) ; ( b ) corresponding lbc ( pap stain 40 ) ; positive peritoneal washing in ovarian mucinous carcinoma ( c ) cps ( mgg 100 ) ; ( d ) corresponding lbc ( pap stain 100 ) positive peritoneal washing in squamous cell carcinoma arising in ovarian teratoma ( a ) cps ( mgg 100 ) ; ( b ) corresponding lbc ( pap stain 100 ) ; positive peritoneal washing in ovarian serous carcinoma ( c ) cps showing only mesothelial cells ( mgg 40 ) ; ( d ) corresponding lbc showing a cluster of malignant cells ( pap stain 100 ) uterine causes included 2/45 ( 4.4% ) cases of endometrioid adenocarcinoma ,  ( 25% ) cases of clear cell carcinoma ,  ( 50% ) cases of carcinosarcoma , and 1/4 ( 25% ) cases of cervix carcinoma [ tables 1 and 2 ] . on review , 14 cases were identified in which peritoneal washings were reported as negative , both on conventional smear as well as the lbc smear , whereas histopathological examination of the omentum revealed tumor deposits . further review of the smears ( both conventional and lbc smears ) of these cases failed to reveal any tumor cells . distribution of ovarian neoplasms distribution of uterine neoplasms there were 2 cases of sertoli leydig cell tumor , 3 cases of fibroma thecoma , 15 cases of mature cystic teratoma of ovary , and 5 cases of leiomyosarcoma , where the peritoneal cytology was negative . the histopathological diagnoses of other cases with negative peritoneal washings included leiomyoma , adenomyosis , follicular , endometriotic and simple cyst of ovaries , serous cystadenomas , mucinous cystadenoma , cervicitis , salpingitis , etc . distribution of cases with negative peritoneal cytology all the positive cases ( n = 83 ) were reviewed by two cytopathologists mainly concentrating on cytologic features , which were different in two techniques ( conventional and lbc sure path ) . lbc smears were easier to study , small circular smears of 13 mm diameter , with uniformly distributed , concentrated cells . all the lbc smears were devoid of hemorrhagic background and debris , which was a confounding feature in conventional smears of 257 out of 393 cases . in our department , conventionally , after that , conventional smear stained with papanicolaou stain is examined , followed by lbc smear . thus , it was observed that conventional smears of 4 cases had no cells , however , lbc smears showed presence of tumor cell clusters . these cases on follow - up histopathology were diagnosed as ovarian high - grade serous carcinoma with omental metastases . there were 6 cases whose conventional smears had low cellularity ( less than three tumor cell clusters in the entire smear ) , however , lbc smears displayed uniformly present tumor cells [ figure 2c and d ] , indicating a better diagnostic accuracy of the lbc technique . peritoneal wash cytology helps in the management of gynecological malignancies by identifying microscopic intraperitoneal metastatic deposits and helps in the surgical staging of these tumors . during second - look  laparotomy with negative peritoneal cytology , the patient may be considered disease free and chemotherapy may be discontinued accordingly . serous ovarian carcinoma was found to be the most common gynecological malignancy resulting in positive peritoneal cytology in the present study . we also observed positive peritoneal cytology in 3 cases of dysgerminoma , 2 cases of yolk sac tumor , and 1 case of granulosa cell tumor . one case showed squamous cell carcinoma arising in teratoma , which led to shedding of malignant squamoid cells in the peritoneal wash fluid . jacques et al . in 1991 studied multiple peritoneal cytologies collected during laparotomy for gynecologic malignancies and showed 23/61 cases of positive peritoneal cytology due to ovarian causes . positive peritoneal cytology is associated with high recurrence rate and decreased survival in endometrial cancer . ( 1981 ) found that stage i endometrial carcinoma cases with negative peritoneal cytology did not recur , whereas tumor recurrence at shorter interval was observed in cases with positive peritoneal cytology . however , according to yazigi et al . ( 1983 ) , positive peritoneal cytology did not influence prognosis in stage i endometrial carcinoma . tubal transportation , exfoliation from extrauterine tumor deposits , contamination from manipulation during endometrial sampling or intracavitary therapy or other procedures , and lymphatic spread have been proposed as factors contributing to the spread of malignant cells in the peritoneal cavity . one out of two cases of carcinosarcoma of the uterus also showed positivity for malignant cells in peritoneal lavage in the present study . tumor cells are commonly observed from the carcinomatous component of carcinosarcoma because this component is less cohesive and is easily shed into washing samples . selvaggi and jacques ( 1991 ) reported negative peritoneal cytology in all 33 cases of cervical carcinoma in their study . false positive peritoneal washings , where peritoneal washings are reported as positive in absence of any known tumor in the patient has been described previously . we did not observe any such case with false positive peritoneal cytology , similar to ziselman et al . this observation may be explained by the fact that all the suspicious cases were reported along with corresponding gynecologic specimens . there were 14 false negative cases ( negative peritoneal washings but had omental tumor deposits on histology ) in the present study . . this could be because of dilution of sample with blood and less number of malignant cells in fluid . four cases in the present study had only blood in conventional smears , and malignant cells could be identified on lbc smears only . in another 6 cases , conventional smears had less than three clusters of malignant cells , whereas lbc smears helped to concentrate and better delineate the tumor cells . the negative peritoneal cytology may be explained by poor distribution or infrequent exfoliation of tumor cells . this shortcoming is overcome in lbc technique where preservative solution lyses the rbcs and cell enrichment process results in uniform homogenous concentration of cells within the circular smear . the excessive amount of fluid may also dilute the tumor cells , making their identification difficult in conventional preparations . these factors may result in false negative peritoneal cytology which can be detrimental to the patient 's clinical outcome . lbc preparation offers advantage in hemorrhagic and paucicellular samples improving the diagnostic accuracy of peritoneal washings . residual material from lbc samples can also be utilized for ancillary techniques such as immunocytochemistry ( icc ) . icc can directly be done on lbc smears . however , in our study , we did not perform immunocytochemistry on lbc sample for diagnosis . lbc smears also reduce the time of observer to hunt for tumor cells because cells are uniformly distributed and concentrated in the circular smear . these factors result in improved productivity by reducing the inadequate rate and increasing the diagnostic accuracy of peritoneal cytology . in conclusion , papillary serous carcinoma is the most common ovarian malignancy leading to positive peritoneal cytology and presenting at advanced stages . endometrioid adenocarcinoma rarely leads to positive peritoneal cytology , especially when myometrial invasion is more than 50% and/or with parametrial involvement . lbc technique leads to concentration of tumor cells causing reduction in false negative cases , especially in hemorrhagic and paucicellular cases , thereby improving the diagnostic accuracy of peritoneal washings . the correct identification of malignant cells in peritoneal wash fluids is essential for the proper management of gynecological cancer , especially early stage carcinomas .
context : peritoneal washing is performed for staging of gynecologic tumors to detect subclinical intraperitoneal metastases.aim:the aim of the present study was to assess the impact of surepath liquid - based cytology ( lbc ) in peritoneal washing in various gynecological malignancies.settings and design : an audit of peritoneal - fluid / washing ( january 2012 to july 2013 ) was performed with corresponding gynecologic specimens . 
 all peritoneal washings were processed using both conventional and lbc technique . 
 suspicious cases on cytology were reported along with gynecologic specimens.results:there were a total of 393 peritoneal fluids . 
 eighty - three ( 21.1% ) were positive for malignancy , and the corresponding histology was available in 352 ( 89.6% ) cases . 
 sixty - nine positive samples had ovarian malignancies and 5 had uterine causes . 
 there were 9 cases of peritoneal washings in which no histopathology was available . 
 the most common cause of positive peritoneal cytology was ovarian serous carcinoma in 55/84 ( 65.5% ) cases . 
 other causes included mucinous cystadenocarcinoma , dysgerminoma , squamous cell carcinoma in teratoma , yolk sac tumor , and granulosa cell tumor . 
 uterine causes included 2/45 ( 4.4% ) cases of endometrioid adenocarcinoma ,  ( 25% ) cases of clear cell carcinoma ,  ( 50% ) cases of carcinosarcoma , and  ( 25% ) cervix carcinoma . on review of positive cases 
 ( n = 83 ) , 10 cases were identified , which had nil ( n = 4 ) to low cellularity ( <3 tumor clusters / smear ; n = 6 ) on conventional smears , and were confirmed malignant on lbc.conclusions:the most common ovarian malignancy causing positive peritoneal cytology is papillary serous carcinoma . 
 endometrioid adenocarcinoma rarely leads to positive peritoneal cytology . 
 lbc technique leads to concentration of tumor cells causing reduction in false negative cases , especially in hemorrhagic and low - cellular cases .