Cells In Peritoneal Washings Research Articles

Comparison of the Number of Spindle Cells in Peritoneal Washings between Laparoscopic Myomectomy with Morcellation and Open Myomectomy without Morcellation

This study evaluated peritoneal washings for the detection of spindle cells (SCs) in laparoscopic and open myomectomies. Prospective, nonrandomized clinical trial. An academic tertiary referral center. Women suspected of having benign uterine myoma undergoing laparoscopic or open myomectomy from October 2016 to April 2018. Washing of the peritoneal cavity to detect SCs was performed twice during the laparoscopic myomectomy. The first washing was after the closure of the myometrial incision and before morcellation. The second one was performed after morcellation. The procedure was also performed once during the open myomectomy, after the completion of the myomectomy and the closure of the incision. After a peritoneal washing with 200 mL normal saline, 30 mL liquid was collected and sent to the laboratory for SC detection. Surgical parameters such as operating time, mean change in serum hemoglobin level, complications, length of hospital stay, and readmission were compared between the 2 groups. A total of 150 participants were included in the analysis: 78 in the laparoscopic group and 72 in the open myomectomy group. After morcellation, the incidence of SCs was 2.6% (n = 2) and 6.9% (n = 5) in the laparoscopic and open myomectomy groups, respectively (p = .204). SCs were observed in both the laparoscopic and open myomectomy groups. Thus, morcellation alone could not be the cause for SC dissemination, which might also be triggered by the manipulation of myoma(s).

Gastric cancer with high risk of intraperitoneal progression: clinical course and current treatments

Abstract Locally advanced gastric cancer with a high risk of intraperitoneal progression is characterized by poor prognosis. After radical surgery, most patients die during the first two years post-operation as a result of disease progression. The prevailing type of progression and the leading cause of death in patients with gastric cancer is implantation metastasis. The main risk factors for peritoneal carcinomatosis in such patients include: gastric tumor invasion into serosa, the presence of tumor cells in peritoneal washings, the largeness of the tumor as accompanied by extensive serous lesions, infiltrative type of tumor growth, histological variants of gastric cancer prone to implantation metastasis and metastatic lesions in regional lymph nodes. Systemic chemotherapy does not provide effective eradication of subclinical peritoneal carcinomatosis in patients with locally advanced gastric cancer. The vast majority of patients who suffer from locally advanced gastric cancer and run a high risk of implantation metastasis are characterized by subclinical peritoneal dissemination at primary diagnosis, which means a rapidly fatal prognosis for such patients. In recent years, however, the paradigm of treatment of locally advanced gastric cancer has changed: a combination of surgery and adjuvant hyperthermic intraperitoneal chemotherapy is used increasingly, and presents an alternative to the previously accepted surgery only approach. It is also likely to increase the survival rate.

Oncolytic Virotherapy Increases the Detection of Microscopic Metastatic Disease at Time of Staging Laparoscopy for Pancreatic Adenocarcinoma

The field of oncolytic virotherapy has undergone much growth in recent years as improvements in vector design have resulted in augmented selectivity for specific cancer types as well as more potent anti-cancer effects. There is probably no greater evidence of such progress as the recent Food and Drug Administration (FDA) approval of talimogene laherparepvec (T-VEC) for the treatment of melanoma following the published results of the OPTiM study (Andtbacka et al., 2015). As the first FDA-approved oncolytic virotherapy in the United States, it will hopefully serve as a stepping-stone for the development and approval of additional viral-based therapies. Another important component to the evolution of oncolytic virotherapy has been its use in non-invasive bioimaging. With increasing numbers of vectors entering into trials, the ability to effectively monitor the pharmacokinetics and pharmacodynamics of infection will be critical. Some groups have employed transgenes such as an enhanced green fluorescent protein (eGFP) to analyze fluorescence from their vectors (Adusumilli et al., 2011). Other avenues of investigation have looked into reporter genes encoding membrane transport proteins such as the sodium iodide symporter (NIS) (Miller and Russell, 2016). One application of these molecular imaging techniques is to use the information that they can provide to augment diagnostic techniques in difficult clinical situations. For example, pancreatic adenocarcinoma has one of the poorest survivals for all types of malignancies. Even with modern chemotherapeutics and clinical care, the overall five year survival rate is only on the order of 6%. For patients with localized disease, surgical resection remains a cornerstone of therapy. A critical component to care of these patients is ensuring that they are appropriate candidates for surgery, and that they do not have metastatic disease. Staging laparoscopy has the potential for identifying metastatic liver or peritoneal disease in patients who were otherwise thought to have only localized disease on cross sectional imaging (Pisters et al., 2001). This practice has not been universally adopted and there is no standard criteria for selecting the appropriate patients (De Rosa et al., 2016). However, some authors have found a correlation between elevated serum CA 19-9 levels and findings of metastatic disease at the time of laparoscopy, and thereby suggest that these patients may be better candidates to undergo such a procedure (Karachristos et al., 2005). Cytological analysis performed following staging laparoscopy for patient with pancreatic adenocarcinoma is highly specific, but lacking in sensitivity. This study by Kelly et al. has sought to improve upon conventional cytology by employing a modified herpes virus expressing the eGFP gene to better identify tumor cells in peritoneal washings (Kelly et al., 2016). The NV1066 virus used in the study is an attenuated, replication-competent oncolytic herpes simplex virus type 1 (HSV-1). Additionally, the eGFP transgene was inserted into the virus genome and is under the control of the cytomegalovirus promoter. Previously, this vector has been demonstrated to have the ability to detect as few as one cancer cell in a background of one million normal cells (Adusumilli et al., 2011). Eighty-two patients with proven pancreatic adenocarcinoma were enrolled in the study. Peritoneal washing were obtained during diagnostic laparoscopy and then analyzed by conventional cytology and HSV-mediated fluorescence detection. In the cytology arm, the sensitivities for detecting any metastatic disease and for the detection of peritoneal metastases were 44% and 89% respectively. In contrast, the viral-mediated detection arm had sensitivities of 94% and 100% respectively. For those patients with negative conventional cytology who went on to curative-intent surgery, there was a statistically significant (p = 0.01) decrease in recurrence free survival for those patients who were eGFP positive (6.5 months) compared to eGFP negative patients (12.2 months). As the authors have explained, many patients with pancreatic cancer undergo staging laparoscopy and peritoneal washings, only to have a false-negative result upon cytological analysis. In this manuscript, they have clearly demonstrated that their modified herpes virus was effective at infecting and replicating within pancreatic adenocarcinoma cells from many different patients. This application of oncolytic virus-based imaging outperforms conventional cytology approaches as evidence by the markedly increased diagnostic sensitivity. This type of information can and will be helpful in guiding clinical decision making for patients with pancreatic adenocarcinoma. Given the results of this study, it is clear that this herpes simplex oncolytic virus deserves further testing in larger trials so that it can continue to move towards FDA approval for clinical use. The potential applications of this vector extend beyond pancreatic cancer, and we would also anticipate that the authors will be pursuing additional studies analyzing peritoneal washings for other malignancies, such as gastric cancer.

Utility of peritoneal washing cytology in staging and prognosis of ovarian and fallopian tube neoplasms: a 10-year retrospective analysis.

The prognostic significance of peritoneal washing cytology in gynecologic neoplasms is controversial. The presence of neoplastic cells in peritoneal washings is currently part of the Federation of Gynecology and Obstetrics and American Joint Committee on Cancer TNM staging systems in cases of ovarian and fallopian tube neoplasms without metastasis beyond the pelvis. In this study, we retrospectively reviewed all cases of ovarian and fallopian tube neoplasms in which cytologic studies were performed. The utility of cytology in tumor staging and the relationship between cytology results and patient outcome are studied. All cases of ovarian and fallopian tube neoplasms in our institution between July 2002 and July 2012 were reviewed. Primary tumor characteristics including type and pelvic extension were collected, categorized, and correlated with peritoneal washing cytology. Final tumor staging was reviewed and the impact of positive cytology was evaluated. A total of 120 cases of ovarian and fallopian tube neoplasms without extrapelvic metastasis were identified within the study period. Peritoneal washing cytology was positive in 24% (29/120) of neoplasms and upstaged the tumor 83% (24/29) of the time when positive. Overall, 20% (24/120) of reviewed cases were upstaged based on positive cytology results. Peritoneal washing cytology remains a useful staging tool for ovarian and fallopian tube neoplasms limited to the pelvic cavity. Positive cytology results in upstaging in a significant proportion of the cases regardless of the tumor type. A larger study is needed to analyze follow-up data to determine if upstaging based on positive cytology adversely affects outcome.

Human Trial of a Genetically Modified Herpes Simplex Virus for Rapid Detection of Positive Peritoneal Cytology in the Staging of Pancreatic Cancer

IntroductionPatients with peritoneal dissemination of pancreatic adenocarcinoma do not benefit from surgical resection, but radiologic and cytologic detection of peritoneal cancer lack sensitivity. This trial sought to determine if an oncolytic virus may be used as a diagnostic agent to detect peritoneal cancer. MethodsPeritoneal washings from patients with pancreatic adenocarcinoma were incubated with the enhanced green fluorescent protein (eGFP)-expressing oncolytic herpes simplex virus (HSV) NV1066. eGFP-positive or negative status was recorded for each specimen and compared to results obtained by conventional cytologic evaluation. These results were correlated with recurrence and survival for patients who underwent R0 resection. ResultsOf 82 patients entered in this trial, 12 (15%) had positive cytology and 50 (61%) had virally-mediated eGFP positive cells in peritoneal washings. All cytology-positive patients were also eGFP positive. HSV-mediated fluorescence detection had sensitivities of 94% and 100% for detection of any and peritoneal metastatic disease; respectively. Median recurrence free and disease specific survival were 6.5 and 18.3months for eGFP positive patients, versus 12.2 and 36.2months for eGFP negative patients (P=0.01 and 0.19); respectively. ConclusionsA genetically modified HSV can be used as a highly sensitive diagnostic agent for detection of micro-metastatic disease in patients with pancreatic adenocarcinoma and may improve patient selection for surgery.

Peritoneal Washings After Power Morcellation in Laparoscopic Myomectomy: A Pilot Study

Study ObjectiveTo evaluate if peritoneal washings of the abdominopelvic cavity during laparoscopic myomectomy can detect leiomyoma cells after power morcellation. DesignProspective cohort pilot study. SettingUniversity of North Carolina Hospitals, an academic, tertiary referral center (Canadian Task Force classification II-2). PatientsPatients undergoing laparoscopic or robotic myomectomy for suspected benign leiomyoma by members of the Minimally Invasive Gynecologic Surgery division between September 2014 and January 2015. InterventionWashings of the peritoneal cavity were collected at 3 times during surgery: the beginning of the procedure once the peritoneal cavity was accessed laparoscopically, after the myoma was excised and myometrial incision closed, and after uncontained power morcellation. Measurements and Main ResultsTwenty patients were included in the analysis. The median morcellation time was 16 minutes (range, 2–36). The median specimen weight was 283.5 g (range, 13–935). Cytologic evaluation (ThinPrep with Papanicolaou staining) did not detect any smooth muscle cells. Cell block histology, however, detected spindle cells in 6 postmorcellation samples. Three of these 6 cases also had spindle cells detected on the postmyomectomy closure samples. When performed on the postmorcellation samples, desmin and smooth muscle actin immunostaining were positive, confirming the presence of smooth muscle cells. ConclusionCell block histology, but not cytology, can detect leiomyoma cells in peritoneal washings after power morcellation. With myomectomy, there is some tissue disruption that seems to cause cell spread even in the absence of morcellation. Further protocol testing might allow peritoneal washings to be used in assessing containment techniques and testing comparative safety of different morcellation methods.

Analysis for the Combination Expression of CK20, FABP1 and MUC2 is Sensitive for the Prediction of Peritoneal Recurrence in Gastric Cancer

Prediction of peritoneal recurrence in gastric cancer patients is important for application of adjuvant chemotherapy. After surgery, occasional patients have peritoneal recurrence despite negative cytology of the peritoneal washings. Thus, molecular detection of a subliminal number of cancer cells in peritoneal washings may overcome the sensitivity limitation of conventional cytology. In this study, expressions of five specific marker genes, namely, TFF1, TFF2, CK20, FABP1 and MUC2, were evaluated for their usefulness as markers of micro-dissemination. It was found that reverse transcriptase-polymerase chain reaction for these five genes yielded results highly specific for the depth of invasion and disease stage. Furthermore, the expression of CK20, FABP1 and MUC2 was a reliable prognostic indicator of peritoneal metastasis. Our results suggest that evaluation of the expression of CK20, FABP1 and MUC2 in peritoneal washings is a useful tool for identifying patients at high risk of peritoneal recurrence who may need adjuvant chemotherapy.

Phase II trial of combined treatment consisting of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for stage IV gastric cancer

To improve the poor prognosis in patients with stage IV (StIV) gastric cancer (GC), we conducted a multicenter phase II study of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for StIV GC (the protocol is registered at the clinical trial site of the National Cancer Institute; KYUH-UHA-GC03-01, NCT00088816). Eligibility criteria included histologically proven StIVGC. Patients received S-1 (80mg/m(2)/day, days 1-21) plus cisplatin (60mg/m(2)on day 8) for 2 courses. After preoperative chemotherapy (CTx), radical gastrectomy was performed. Postoperative S-1 (80mg/m(2)/day, days 1-14) was administered every 3weeks for 1year. Fifty-one patients were enrolled and all patients were followed for more than 2years. The 2-year overall survival and progression-free survival rates were 43.1% (95% confidence interval [CI] 29.4-56.1%) and 33.3% (95% CI 20.9-46.2%), respectively. Preoperative chemotherapy was accomplished in 44 patients (86.3%). These 44 patients underwent surgery and R0 resection was achieved in 26. The rate of R0 resection for GC with a single StIV factor (n=24) was 79.2% and that for GC with multiple StIV factors (n=27) was 25.9%. All patients with cancer cells in peritoneal washings (cytology [Cy] 1) alone (n=12) became Cy0 after preoperative chemotherapy. Postoperative chemotherapy was completed in 11 patients, including 8 with Cy1 alone. No treatment-related death was recorded. Recurrences were observed in 14 patients after R0 resection. The most frequent recurrence site was the peritoneum. Patients who underwent R0 resection and those with Cy1 alone had a better survival. This perioperative treatment was safe and feasible for StIVGC but failed to show a survival benefit. In patients with StIVGC with Cy1 alone this treatment resulted in a better prognosis.

Displaced granulosa cells in peritoneal washings: a rare diagnostic pitfall

CytopathologyVolume 22, Issue 3 p. 202-204 CASE REPORT Displaced granulosa cells in peritoneal washings: a rare diagnostic pitfall D. L. Ribu, D. L. Ribu Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this authorP. W. Shield, P. W. Shield Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this authorD. Cominos, D. Cominos Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this author D. L. Ribu, D. L. Ribu Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this authorP. W. Shield, P. W. Shield Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this authorD. Cominos, D. Cominos Cytology Department, Sullivan Nicolaides Pathology, Brisbane, Qld, AustraliaSearch for more papers by this author First published: 18 May 2011 https://doi.org/10.1111/j.1365-2303.2010.00775.x Dr P. Shield, Cytology Department, Sullivan Nicolaides Pathology, 134 Whitmore St., Taringa, Brisbane 4060, Qld, AustraliaTel.: +61 7 33778592; Fax: +61 7 33778724;E-mail: [email protected] Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume22, Issue3June 2011Pages 202-204 RelatedInformation

Predictive Value of Cancer Stem-Like Cells and Cancer-Associated Genetic Markers for Peritoneal Recurrence of Colorectal Cancer in Patients after Curative Surgery

Objective: The new concept of cancer stem cells has implications in terms of possible application for novel diagnostic and therapeutic procedures. Recently, the CD133 molecule was reported as a marker of cancer stem-like cells in colorectal cancer (CRC). In this study, we examined the prognostic value of free cancer cells in peritoneal washings from CRC patients after curative resection using multiple molecular markers, including cancer stem-like cells. Methods: A total of 170 CRC patients who had undergone curative surgery were studied. Peritoneal washings of the Douglas cavity were collected and used for cytology and molecular diagnosis. Real-time RT-PCR for carcinoembryonic antigen (CEA), cytokeratin 20 (CK20) and CD133 mRNA was performed to detect free cancer cells. Results: Molecular detection of CEA, CK20 and/or CD133 (CEA/CK20/CD133) mRNA of the peritoneal washings showed a significant correlation with lymph node metastasis and the tumor stage. The overall survival (OS) rates and peritoneal recurrence-free survival (PFS) rates in CEA/CK20/CD133 mRNA-positive patients were significantly lower than those of marker gene-negative patients. CD133/CEA/CK20 mRNAs in peritoneal washings were independent prognostic factors for OS and PFS. Conclusion: Molecular detection of free cancer cells using multimarkers, including cancer stem-like cells in peritoneal washings of post-curative surgery CRC patients, are useful in prognosis prediction.

Rapid Multiple Immunocytochemical Staining Method Using Microwave Irradiation for Intraoperative Cytology

To develop a more rapid and accurate staining procedure for intraoperative cytology through an assessment of a rapid multiple immunocytochemical staining method using microwave irradiation.A preliminary test of a triple immunostaining method using microwave irradiation was performed to determine optimal incubating conditions for primary antibodies against MOC-31, BerEP4 and carcinoembryonic antigen. The test samples were adenocarcinoma cells obtained by washings from 10 resected colorectal cancer specimens. Adenocarcinoma cells in peritoneal washings diagnosed by cytologic examination from 8 colorectal cancer patients were retrospectively examined using the previously determined optimal incubating conditions.High rates of positive cells (83-87%) with intense immunoreactions were obtained using a rapid process with primary antibody concentrations that were 2 times higher than those used for standard incubation at room temperature (82-86%). The staining under these conditions was completed within 19 minutes. Adenocarcinoma cells in the peritoneal washings were also intensely stained under these conditions.Using our microwave method, the processing time was dramatically shortened, and intense and sensitive immunoreactions were obtained. The present method is useful for the rapid and accurate diagnosis of intraoperative cytology.

Challenges in the Interpretation of Peritoneal Cytologic Specimens

Abstract Context.—The presence of malignant cells in peritoneal washings leads to classification as International Federation of Gynecology and Obstetrics stage IC or higher in ovarian carcinomas and at least International Federation of Gynecology and Obstetrics stage IIIA in endometrial carcinomas. Unfortunately, the morphologic examination of cytologic specimens has not proven to be a sensitive or specific diagnostic tool. Malignant cells might be few in number and might be unrecognized among a large population of mesothelial cells and/or macrophages, or reactive mesothelial cells might be misinterpreted as neoplastic cells leading to unnecessary chemotherapy. Objective.—To evaluate the main pitfalls in the evaluation of peritoneal washings in patients with gynecologic malignancies and analyze the ancillary studies that might be helpful to achieve the correct diagnosis with an emphasis on immunocytochemistry. Data Sources.—A comprehensive review of the literature was performed. Conclusions.—Peritoneal ef...

Clinical Significance of Telomerase Activity in Gastric Carcinoma and Peritoneal Dissemination

Telomerase activity is responsible for telomere maintenance and is believed to be crucial in most cancer cells, but its significance in gastric cancer remains unknown. This observational study investigated whether there is a relationship between telomerase activity and the development of gastric cancer, and between telomerase activity and peritoneal dissemination. Telomerase activity was measured in primary gastric cancers and in peritoneal washings from the same patients, and findings were compared with those of conventional cytology and an immunoassay for cancer antigen 125 (CA125). Positive cytological examination and telomerase activity in peritoneal washings both correlated with the histological grade, depth of tumour invasion, area of serosal invasion and peritoneal metastasis. The detection of free cancer cells in peritoneal washings by the telomeric repeat amplification protocol/enzyme-linked immunosorbent assay (TRAP-ELISA) was significantly more sensitive than cytology or the CA125 immunoassay, suggesting that this could be used to diagnose early peritoneal dissemination.

Challenges in the Interpretation of Peritoneal Cytologic Specimens

The presence of malignant cells in peritoneal washings leads to classification as International Federation of Gynecology and Obstetrics stage IC or higher in ovarian carcinomas and at least International Federation of Gynecology and Obstetrics stage IIIA in endometrial carcinomas. Unfortunately, the morphologic examination of cytologic specimens has not proven to be a sensitive or specific diagnostic tool. Malignant cells might be few in number and might be unrecognized among a large population of mesothelial cells and/or macrophages, or reactive mesothelial cells might be misinterpreted as neoplastic cells leading to unnecessary chemotherapy. To evaluate the main pitfalls in the evaluation of peritoneal washings in patients with gynecologic malignancies and analyze the ancillary studies that might be helpful to achieve the correct diagnosis with an emphasis on immunocytochemistry. A comprehensive review of the literature was performed. Peritoneal effusions may represent major challenges to the pathologist and can have important clinical implications. Immunostains for epithelial markers such as B72.3, MOC-31, and Ber-EP4 represent the best available markers to identify epithelial cells. Caution is advised to not overdiagnose endometriosis or endosalpingiosis as adenocarcinoma.

A phase II study of radical surgery followed by postoperative chemotherapy with S-1 for gastric carcinoma with free cancer cells in the peritoneal cavity (CCOG0301 study)

Background Patients with gastric cancer who have positive cytologic results for cancer cells in peritoneal washings (CY1) have poor outcomes, even in the absence of other distant metastases. A standard treatment for such patients remains to be established. Methods We conducted a phase II trial with the 2-year survival rate as the primary endpoint. Patients who had gastric cancer with CY1 status but no other residual disease received postoperative chemotherapy with S-1 (1 M tegafur–0.4 M gimestat–1 M otastat potassium) at a daily dose of 80 mg/m 2 for 4 weeks, followed by 2 weeks of rest. This cycle was continued until disease progression or intolerable adverse events. D2 dissection was the recommended surgical procedure; splenectomy could be omitted at the discretion of the surgeon. Accrual of 50 patients was planned, and a 2-year survival rate of more than 36% was needed to exceed the historical control. Results Forty-eight patients were enrolled, among whom 47 were assessable for survival and 46 for adverse reactions. Median overall survival was 705 days, and progression-free survival was 376 days. The 2-year survival rate was 47%. Median time to treatment failure was 288 days. Neutropenia was the commonest ≥grade 3 toxicity (6 patients), and anorexia was the most frequent ≥grade 2 non-hematologic toxicity (10 patients). Conclusions Gastrectomy followed by S-1 monotherapy resulted in survival that surpassed historical data and can serve as an active control treatment for future trials in patients who have gastric cancer with CY1 status in the Far East.

Detection of Minimal Gastric Cancer Cells in Peritoneal Washings by Focused Microarray Analysis with Multiple Markers: Clinical Implications

Peritoneal cytology is an important prognostic factor of gastric cancer. However, peritoneal cytology requires great skill, which may explain its low prevalence. A reverse transcriptase-polymerase chain reaction-based assay with multiple marker genes or immunocytochemistry was assessed as an alternative method of gathering the same kind of data as cytology. Peritoneal washings from 179 patients with gastric cancer were analyzed by multiplex reverse transcriptase-polymerase chain reaction with 10 marker genes and subsequent hybridization to a customized oligo-nucleotide array. Results with this assay were either validated as a prognostic factor or confirmed by demonstrating the presence of cancer cells by immunocytochemical cytology. Only 1 (2.2%) of 44 disease-free cases was shown to be positive by the microarray assay, whereas 13 (93%) of 14 conventional cytology-positive cases were found to be positive. This assay further detected approximately one-third of cytology-negative patients either with peritoneal recurrence (7 of 20, 35%) or with non-peritoneal recurrence (6 of 22, 27%). A high concordance between the microarray assay and immunocytochemical cytology with five antibodies against CK20, FABP1, MUC2, TFF1, and MASPIN was confirmed. The clinical outcome of the microarray assay-positive cases was poor, as was that of the cytology-positive cases. Our assay, though time-consuming and requiring special equipment, demonstrated a specificity and sensitivity equal to or better than cytology in our institutes. The minimal free peritoneal cancer cells detected by the microarray assay may provide the same clinical information as larger amounts of cancer cells for patients with gastric cancer. An anti-MASPIN antibody may be helpful in peritoneal cytology of gastric cancer.

Peritoneal Cytology in Patients with Potentially Resectable Adenocarcinoma of the Pancreas

The prognostic significance of malignant cells in the peritoneal washings of patients with pancreatic adenocarcinoma remains poorly defined. Prior reports suggest that positive peritoneal cytology (PPC) is associated with advanced disease and reduced survival. To determine the prognostic value of PPC in patients with pancreatic cancer, we retrospectively reviewed our database between July 1987 and September 2002 and identified 168 patients who had undergone exploration for potentially resectable pancreatic cancer with peritoneal washings performed at the time of exploration. One hundred thirty-five patients underwent resection; 33 were considered unresectable. PPC was reported for 27 patients (16.1%): 13 (9.6%) in the resected and 14 (42.4%) in the unresected group. Median time to macroscopically detected recurrence in the resected group was not significantly different in the PPC versus negative peritoneal cytology (NPC) patients (10 vs 12 months, P = 0.46). Median overall survival of patients with PPC versus NPC approached, but did not reach, significance (15 vs 19 months, P = 0.055). Peritoneal cytology status was not associated with administration of chemoradiation, margin status, antecedent fine-needle aspiration, stage, or site of recurrence. These data suggest that malignant cells in peritoneal washings of patients with potentially resectable pancreatic adenocarcinoma should not preclude resection. Long-term survival may be achieved, therefore aggressive treatment should strongly be considered.

Diagnostic pitfalls of peritoneal washing cytology and the role of cell blocks in their diagnosis.

Mesothelial cell hyperplasia, collagen balls, endometriosis, and endosalpingiosis are diagnostic pitfalls on peritoneal washing cytology in women who present with gynecologic lesions. Over an 8-month period, the peritoneal washings from 10 patients undergoing gynecologic surgery for presumed malignancy showed unusual cytologic findings, several of which posed diagnostic difficulties. The washings from four patients with ovarian carcinomas were cellular and contained clusters and strips of cells with cytologic atypia mimicking malignancy. Confirmation of their benign mesothelial origin was confirmed on immunohistochemistry utilizing cell block preparations. In two cases of endometrial endometrioid carcinoma, the washings contained several clusters of cells surrounding and/or admixed with a globular substance. Due to their similarity to endometrial cells, immunohistochemistry was performed on cell block preparations. The cells were positive for cytokeratin and negative for carcinoembryonic antigen and B72.3, confirming their mesothelial origin. In one case, clinically presumed to be a malignant mass, the washings contained tight clusters of cells with mild cytologic atypia admixed with hemosiderin-laden macrophages. In conjunction with the cell block findings, a diagnosis of endometriosis was made. Extensive endometriosis was found on the surgically resected specimen. In two cases, strips of ciliated epithelial cells resembling tubal epithelium were present on the cytologic and cell block preparations, consistent with endosalpingiosis. The peritoneal washings in one case contained several clusters and balls of atypical cells surrounding microcalcifications on cell block preparation. Since calcification within groups of cells in peritoneal washings always raised the possibility of malignancy, a serous carcinoma of the ovary, particularly of borderline malignancy, would have to be excluded. Fortunately, the resected specimen was free of tumor and showed calcified endosalpingiosis on the ovarian surface. Preparation of cell blocks from peritoneal washings is of value in the work-up and management of patients who present with cytologic mimickers of malignancy on fluid cytology.

Neutrophils Mediate Parenchymal Tissue Necrosis and Accelerate the Rejection of Complete Major Histocompatibility Complex-Disparate Cardiac Allografts in the Absence of Interferon-γ

A major feature of acute rejection of cardiac allografts is an intense mononuclear cell infiltration accompanied by interferon (IFN)-gamma production. In the current study we tested the role of IFN-gamma in acute rejection of allografts by comparing the histopathology of rejection in wild-type versus IFN-gamma-/- recipients of major histocompatibility complex-mismatched cardiac grafts. Wild-type recipients rejected the allografts at days 8 to 9 after transplant but rejection was accelerated 2 to 3 days in IFN-gamma-deficient recipients. During rejection in wild-type recipients, the allografts were heavily infiltrated with CD8+ T cells and other mononuclear cells. In contrast, allografts in IFN-gamma-deficient recipients had few T cells but an intense neutrophil infiltration accompanied by extensive graft parenchymal necrosis. No difference in expression levels of neutrophil chemoattractants including Groalpha/KC, MIP-2, GCP-2, and MIP-1alpha, was observed in allografts retrieved from wild-type and IFN-gamma-/- recipients. Depletion of neutrophils from IFN-gamma-deficient recipients delayed rejection until days 8 to 10 after transplant and restored the histopathology of acute allograft rejection to that observed in allografts rejected by wild-type recipients. These results indicate the potent regulatory properties of IFN-gamma during acute rejection directed at neutrophil infiltration into allografts and mediating graft tissue necrosis.

Use of E-cadherin and CD44 aids in the differentiation between reactive mesothelial cells and carcinoma cells in pelvic washings.

The presence of malignant cells in peritoneal washings is an independent prognostic factor in the evaluation of gynecologic malignancies. The differentiation between reactive mesothelial cells and carcinoma cells can be a diagnostic challenge based on morphology alone. The expression of some cell adhesion molecules may be helpful in the differential diagnosis. To evaluate the specificity of 2 transmembrane cell adhesion proteins (E-cadherin and CD44) in the differentiation of mesothelial cells from carcinoma cells in pelvic washings, formalin fixed, paraffin embedded cell blocks of pelvic washings from 19 cases of metastatic ovarian adenocarcinoma and 16 cases of benign peritoneal washings were immunostained with monoclonal antibodies to E-cadherin and CD44. The staining patterns were evaluated blindly by three observers. Positive staining was defined as uniform membranous staining for each marker. Fourteen benign peritoneal washings (87.5%) demonstrated immunoreactivity with anti-CD44. On the contrary, only four adenocarcinomas (21.1%) demonstrated anti-CD44 immunoreactivity. E-cadherin expression was identified in only 2 benign peritoneal washings (12.5%) whereas 16 adenocarcinomas (84.2%) strongly expressed E-cadherin. The differences in immunostaining for both CD44 and E-cadherin between benign and malignant peritoneal washings were statistically significant. The combination of positive staining for E-cadherin and negative staining for CD44 was 100% specific for metastatic adenocarcinoma, whereas a combination of negative staining for E-cadherin and positive staining for CD44 was 100% specific for reactive mesothelial cells. Both E-cadherin and CD44 reliably distinguish reactive mesothelial cells from adenocarcinoma. The combination of E-cadherin/CD44 is highly specific and is a useful diagnostic adjunct with which to distinguish benign reactive mesothelial cells from adenocarcinoma in pelvic washings.