Minimally Invasive, Maximally Effective: The Power of Precision Cytoanalysis on Effusion Samples-A Comprehensive Exploration from Traditional Methods to Innovative Approaches.

Precision medicine translates through molecular assays and in minimally invasive diagnosis, evident in analyses of effusions that serve therapeutic and diagnostic purposes. This cost-effective and low-risk approach provides advantages, playing a pivotal role in late-stage oncology and frequently standing as the primary resource for cancer diagnosis and treatment pathways. This article outlines the workflow for managing serous fluid and explores how cytology effusion analysis extends beyond immunocytological diagnosis. Combined with current molecular tests it showcases the potential to be a skillful tool in precision cytopathology.

Prognostic value of 24-hour cultivation of peritoneal fluid to distinguish complicated from uncomplicated acute appendicitis: a prospective cohort study.

BACKGROUND: The distinction between complicated and uncomplicated acute appendicitis (AA) is important as it guides postoperative antibiotic treatment. A diagnosis based on intraoperative findings is imprecise and standard cultivation of peritoneal fluid is generally time-consuming with little clinical benefit. The aim of this study was to examine if cultivation of peritoneal fluid in acute appendicitis could reliably detect bacteria within 24 h. METHODS: Patients older than 18 years undergoing laparoscopic appendectomy were prospectively enrolled at two surgical departments after informed consent was obtained. Periappendicular fluid was collected prior to appendectomy and sent for cultivation. Sensitivity, specificity and positive and negative predictive values were calculated with 95% confidence intervals (CIs) using 72-hour cultivation results as the gold standard. Patients with complicated AA as determined by the surgeon, received a three-day course of oral antibiotics. Postoperative infectious complications within 30 days after surgery were registered. RESULTS: From July 2020 to January 2021, 101 patients were included. The intraoperative diagnosis was complicated AA in 34 cases. Of these patients, six (17.6%) had bacteria cultured within 24 h after surgery, leading to a sensitivity of 60% and a specificity of 100%. The positive and negative predictive values were 1.00 and 0.96, respectively. Seven patients developed a postoperative infection (five superficial wound infections and two intra-abdominal abscess). In all cases with a positive cultivation result, the intraoperative diagnosis was complicated appendicitis and a postoperative course of antibiotics prescribed. CONCLUSION: Twenty-four-hour cultivation of the peritoneal fluid in acute appendicitis is a valid indicator for peritoneal bacterial contamination. Randomized studies are necessary to determine if this approach is suitable for targeting postoperative antibiotic treatment as a means to prevent overtreatment without increasing the risk of infectious complications.

Therapeutic potential of oral alginate nanoparticles against experimental toxoplasmosis.

Side effects and low efficacy of current anti-toxoplasmosis therapeutics against encysted bradyzoites necessitate research into alternative safe therapeutic options. The safety, immunostimulatory, and antimicrobial properties of alginate nanoparticle formulation (Alg-NP) highlight its potential as an oral therapy against acute toxoplasmosis. In the current study, Alg-NP was formulated and characterized and then assessed for its anti-Toxoplasma effects using parasitological, ultrastructural, immunological, and histopathological studies. Treatment with Alg-NP significantly prolonged mice survival and reduced the parasite burden in both peritoneal fluid and tissue impression smears. In addition, it altered parasite viability and caused severe tachyzoite deformities as evidenced by ultrastructural studies. Alg-NP induced high levels of serum IFN-γ in infected mice with significant amelioration in histopathological changes in both hepatic and splenic tissue sections. In conclusion, Alg-NP could be considered a promising therapeutic agent against acute murine toxoplasmosis, and owing to its safety, it could potentially be enlisted for human use.

CCL18 promotes endometriosis by increasing endometrial cell migration and neuroangiogenesis.

Endometriosis is an estrogen-dependent inflammatory gynecological disease whose pathogenesis is unclear. C-C motif chemokine ligand 18 (CCL18), a chemokine, is involved in several inflammatory diseases. In this study, we aimed to investigate the role of CCL18 in endometriosis and its underlying mechanisms. Human endometrium and peritoneal fluid were obtained from women with and without endometriosis for molecular studies. The expression level of CCL18 in each tissue sample was examined by RNA sequencing analysis, quantitative PCR analysis and immunohistochemistry staining. The effects of CCL18 on cell migration, tube formation and neurite growth were investigated in vitro using primary endometrial cells, human umbilical vein endothelial cells (HUVECs) and dorsal root ganglion (DRG) neurons, respectively. Moreover, the development of endometriosis in mice was studied in vivo by blocking CCL18. CCL18 was shown to be overexpressed in endometrial foci and peritoneal fluid in women with endometriosis and was positively correlated with endometriosis pain. In vitro, CCL18 promoted the migration of ectopic endometrial cells, tube formation of HUVECs, and nerve outgrowth of DRG neurons. More importantly, inhibition of CCL18 significantly suppressed lesion development, angiogenesis, and nerve infiltration in a mouse model of endometriosis. In conclusion, CCL18 may play a role in the progression of endometriosis by increasing endometrial cell migration and promoting neuroangiogenesis.

[Application of cell blocks to assist in precise cytological diagnosis of serous effusion].

Objective: To investigate the importance of cell block and immunohistochemistry in the accurate diagnosis of serous effusion. Methods: A retrospective study was conducted on 3 124 cases of serous effusion from the Department of Pathology, Beijing Hospital from 2018 to 2022, include 2 213 cases of pleural effusion, 768 cases of peritoneal effusion, 143 cases of pericardial effusion. There were 1 699 males (54.4%) and 1 425 females (45.6%), average age 69 years old. Of which 1 292 cases were prepared with cell blocks and examined with immunohistochemical stain. Results: The percentage of malignant diagnosis increased from 64.9% (839/1 292) to 84.0% (1 086/1 292) after cell block preparation, and 1 086 cases were accurately diagnosed with histological type and/or origin of primary tumor. The undetermined diagnosis of suspected malignancy decreased from 13.3% (172/1 292) to 0.1% (1/1 292) and that of atypical hyperplasia from 18.8% (243/1 292) to 0.4% (5/1 292). The negative result for malignancy rate increased from 3.0% (38/1 292) to 15.5% (200/1 292). The differences highlighted above were statistically significant (Pearson's chi-squared test=12.739, P<0.01). Conclusion: Application of immunohistochemistry based on cell block can significantly improve malignant diagnosis in serous effusion, identify tumor origin and histological type as well as decrease the uncertain diagnosis.

Positive peritoneal lavage fluid cytology based on isolation by size of epithelial tumor cells indicates a high risk of peritoneal metastasis.

Background: Peritoneal metastasis (PM) is the most prevalent type of metastasis in patients with gastric cancer (GC) and has an extremely poor prognosis. The detection of free cancer cells (FCCs) in the peritoneal cavity has been demonstrated to be one of the worst prognostic factors for GC. However, there is a lack of sensitive detection methods for FCCs in the peritoneal cavity. This study aimed to use a new peritoneal lavage fluid cytology examination to detect FCCs in patients with GC, and to explore its clinical significance on diagnosing of occult peritoneal metastasis (OPM) and prognosis. Methods: Peritoneal lavage fluid from 50 patients with GC was obtained and processed via the isolation by size of epithelial tumor cells (ISET) method. Immunofluorescence and fluorescence in situ hybridization (FISH) were used to identify FCCs expressing chromosome 8 (CEP8), chromosome 17 (CEP17), and epithelial cell adhesion molecule (EpCAM). Results: Using a combination of the ISET platform and immunofluorescence-FISH, the detection of FCCs was higher than that by light microscopy (24.0% vs. 2.0%). Samples were categorized into positive and negative groups, based on the expressions of CEP8, CEP17, and EpCAM. Statistically significant relationships were demonstrated between age (P = 0.029), sex (P = 0.002), lymphatic invasion (P = 0.001), pTNM stage (P = 0.001), and positivity for FCCs. After adjusting for covariates, patients with positive FCCs had lower progression-free survival than patients with negative FCCs. Conclusion: The ISET platform highly enriched nucleated cells from peritoneal lavage fluid, and indicators comprising EpCAM, CEP8, and CEP17 confirmed the diagnosis of FCCs. As a potential detection method, it offers an opportunity for early intervention of OPM and an extension of patient survival.

Altered Monocyte and Lymphocyte Phenotypes Associated with Pathogenesis and Clinical Efficacy of Progestogen Therapy for Peritoneal Endometriosis in Adolescents.

Background: Immunological imbalances characteristic of endometriosis may develop as early as the primary manifestations of the disease in adolescence. Objective: To evaluate subpopulation dynamics of monocytes and lymphocytes in peripheral blood and peritoneal fluid of adolescents with peritoneal endometriosis at diagnosis and after 1-year progestogen therapy. Methods: This study included 70 girls, 13-17 years old, diagnosed laparoscopically with peritoneal endometriosis (n = 50, main group) or paramesonephric cysts (n = 20, comparison group). Phenotypes of monocytes and lymphocytes of the blood and macrophages of the peritoneal fluid were analyzed by flow cytometry at diagnosis and during progestogen therapy. Results: Differential blood counts of CD16+ (p < 0.001) and CD86+ (p = 0.017) monocytes were identified as independent risk factors for peritoneal endometriosis in adolescents. During the treatment, cytotoxic lymphocytes CD56dimCD16bright (p = 0.049) and CD206+ monocytes (p < 0.001) significantly increased while CD163+ monocytes decreased in number (p = 0.017). The CD56dimCD16bright blood counts before (p < 0.001) and during progestogen therapy (p = 0.006), as well as CD206+ blood counts during the treatment (p = 0.038), were associated with the efficacy of pain relief after 1-year progestogen therapy. Conclusions: Adolescents with peritoneal endometriosis have altered counts of pro- and anti-inflammatory monocytes and lymphocytes both before and after 1-year progestogen therapy, correlating with treatment efficacy and justifying long-term hormonal therapy.

BioFire blood culture identification 2 panel as detector of bacteria in peritoneal fluid from patients with acute appendicitis.

BACKGROUND: Polymerase chain reaction is a method to detect bacterial DNA and is widely used because it delivers results within a few hours with the potential to guide postoperative antibiotic treatment. This study aims to determine if polymerase chain reaction can accurately detect bacteria in the peritoneal fluid compared with conventional culture from patients operated for acute appendicitis. METHODS: This prospective cohort study included patients above the age of 18 years who underwent laparoscopic surgery for acute appendicitis. Peritoneal samples were collected before the appendectomy procedure for conventional culture and polymerase chain reaction using the BioFire Blood Culture Identification 2 Panel for comparison. During surgery, the surgeon assessed the appendicitis as either complicated or noncomplicated. RESULTS: Samples from 102 patients were eligible for analysis. Twelve samples were polymerase chain reaction positive, and 14 samples were culture positive. The concordance of positive results when comparing these 2 methods was 71.4%. The most commonly found bacteria were Escherichia coli and Bacteroides fragilis. Of the 36 patients with complicated appendicitis, no bacteria were detected by either conventional culture or polymerase chain reaction in 21 (58%) of the patients. In patients with uncomplicated appendicitis, bacteria were demonstrated in 1 out of 66 (2%) patients. CONCLUSION: This study suggests that polymerase chain reaction can be used to detect bacteria in the peritoneal fluid and has the potential to guide postoperative antibiotic treatment.

Diagnostic algorithm based on ratio of ascites-serum tumor markers is superior to tumor markers in the differentiation of benign ascites from malignant ascites.

BACKGROUND: Differential diagnosis between benign ascites and malignant ascites remains challenging in clinical practice, the aim of our study is to determine the differential value of the ratio of ascitic-serum tumor markers between benign ascites and malignant ascites. METHODS: 418 patients with new-onset ascites were retrospectively enrolled in this study. The pertinent data of patients enrolled were collected; diagnostic value of tumor markers, ascites-serum tumor marker ratio, and diagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio in patients with ascites were investigated. RESULTS: 81.25% of the patients with benign ascites had low (<1) ratio of ascites-serum tumor markers (Max [A/S CEA, A/S CA15-3, A/S CA19-9]); and 91.88% of patients with benign ascites had the ratio of ascites-serum tumor marker less than 1.5. On the other hand, 94.96% of the patients with malignant ascites had high (≥1) ratio of ascites-serum tumor markers; and 97.29% of patients with malignant ascites had the ratio of ascites-serum tumor markers more than 0.67. Finally, diagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio showed 96.37% of the sensitivity, and 94.37% of the accuracy in the diagnosis of malignant ascites, while ascitic tumor markers with a sensitivity of 78.29%, and an accuracy of 84.93%. CONCLUSIONS: Diagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio exhibited an excellent performance in distinguishing benign and malignant ascites, which should be recommended in patients with new-onset ascites in clinical practice.

TIM-3 Expression in Endometriosis.

PROBLEM: Endometriosis is a prevalent chronic gynecological disease linked to immune dysfunction. The protein T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) plays a crucial role in immune system balance. Malfunction of TIM-3 may result in excessive immune activation and inflammatory tissue damage. Given TIM-3's established role in the development of cancer and autoimmune diseases, we decided to study its role in women suffering from endometriosis. STUDY METHOD: We included a total of 62 female patients, all of whom had undergone laparoscopic surgery. Of these, 47 had endometriosis and 15 did not. During surgery, we collected peritoneal fluid (PF) and peripheral blood (PB) samples from every patient for analysis using flow cytometry. To mark the samples, we used a panel of monoclonal antibodies and examined TIM-3 expression in their immune cells. RESULTS: Endometriosis patients in PB demonstrated a significantly lower percentage of CD56+ T cells with TIM-3 expression. As endometriosis progressed through its stages, this expression lessened. This decrease was particularly notable in women with stage III/IV endometriosis. Additionally, both women diagnosed with intestinal endometriosis and those with recent endometriosis diagnoses showed a significantly reduced percentage of CD56+ T cells expressing TIM-3. CONCLUSIONS: Patients with endometriosis exhibit diminished TIM-3 expression within circulating T cells. This warrants further investigation to discern whether it contributes to the progression of endometriosis, potentially through the amplification of autoreactive T cells and inflammation.

Exosomal ROR1 in peritoneal fluid identifies peritoneal disseminated PDAC and is associated with poor survival.

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest forms of cancer and peritoneal dissemination is one major cause for this poor prognosis. Exosomes have emerged as promising biomarkers for gastrointestinal cancers and can be found in all kinds of bodily fluids, also in peritoneal fluid (PF). This is a unique sample due to its closeness to gastrointestinal malignancies. The receptor tyrosine kinase-like orphan receptor 1 (ROR1) has been identified as a potential biomarker in human cancers and represents a promising target for an immunotherapy approach, which could be considered for future treatment strategies. Here we prospectively analyzed the exosomal surface protein ROR1 (exo-ROR1) in PF in localized PDAC patients (PER-) on the one hand and peritoneal disseminated tumor stages (PER+) on the other hand followed by the correlation of exo-ROR1 with clinical-pathological parameters. Methods: Exosomes were isolated from PF and plasma samples of non-cancerous (NC) (n = 15), chronic pancreatitis (CP) (n = 4), localized PDAC (PER-) (n = 18) and peritoneal disseminated PDAC (PER+) (n = 9) patients and the surface protein ROR1 was detected via FACS analysis. Additionally, soluble ROR1 in PF was analyzed. ROR1 expression in tissue was investigated using western blots (WB), qPCR, and immunohistochemistry (IHC). Exosome isolation was proven by Nano Tracking Analysis (NTA), WB, Transmission electron microscopy (TEM), and BCA protein assay. The results were correlated with clinical data and survival analysis was performed. Results: PDAC (PER+) patients have the highest exo-ROR1 values in PF and can be discriminated from NC (p <0.0001), PDAC (PER-) (p <0.0001), and CP (p = 0.0112). PDAC (PER-) can be discriminated from NC (p = 0.0003). In plasma, exo-ROR1 is not able to distinguish between the groups. While there is no expression of ROR1 in the exocrine pancreatic tissue, PDAC and peritoneal metastasis show expression of ROR1. High exo-ROR1 expression in PF is associated with lower overall survival (p = 0.0482). Conclusion: With exo-ROR1 in PF we found a promising diagnostic and prognostic biomarker possibly discriminating between NC, PDAC (PER-) and PDAC (PER+) and might shed light on future diagnostic and therapeutic concepts in PDAC.

Immunomodulation in Endometriosis: Investigating the interrelationship between VISTA expression and Escherichia.Shigella-Associated metabolites.

AIMS: Endometriosis is characterized by an abnormal immune microenvironment. Despite the extensive use of immune therapies, the application of immune checkpoint inhibitors in endometriosis lacks confidence due to the instability of preclinical research data. This study aims to elucidate the regulation of the immune inhibitory checkpoint VISTA and its effects on T cells from the perspective of microbiota and metabolism. MAIN METHODS: We divided endometriosis patients into high and low groups based on the expression levels of VISTA in lesion tissues. We collected peritoneal fluid samples from these two groups and performed 16 s RNA sequencing and metabolomics analysis to investigate microbial diversity and differential metabolites. Through combined analysis, we identified microbial-associated metabolites and validated their correlation with VISTA and CD8 + T cells using ELISA and immunofluorescence. In vitro experiments were conducted to confirm the regulatory relationship among these factors. KEY FINDINGS: Our findings revealed a distinct correlation between VISTA expression and the microbial colony Escherichia.Shigella. Moreover, we identified the metabolites LTD4-d5 and 2-n-Propylthiazolidine-4-carboxylic acid as being associated with both Escherichia.Shigella and VISTA expression. In vitro experiments confirmed the inhibitory effects of these metabolites on VISTA expression, while they demonstrated a positive regulation of CD8 + T cell infiltration into endometriotic lesions. SIGNIFICANCE: This study reveals the connection between microbial diversity, metabolites, and VISTA expression in the immune microenvironment of endometriosis, providing potential targets for therapeutic interventions.

Abdominocentesis and intra-abdominal pressure measurement in small animals.

OBJECTIVE: To provide a video tutorial detailing how to perform "blind" and ultrasound-guided abdominocentesis for diagnostic and therapeutic guidance, and to provide a brief demonstration of intra-abdominal pressure measurement (IAP). ANIMALS: Any cat or dog with suspicion of free abdominal effusion or patients requiring measurement of IAP. METHODS: Abdominocentesis should be performed when there is high suspicion for peritoneal effusion based on physical exam and/or diagnostic imaging. The 4-quadrant tap uses 20-gauge or larger needles placed blindly in ≥ 1 of the 4 quadrants of the abdomen to collect abdominal fluid. In contrast, ultrasound allows visualization of fluid in the abdomen prior to percutaneous insertion of a needle and syringe to collect fluid. Regardless of collection technique, fluid should have immediate cytologic analysis and later can be submitted for biochemical parameters, additional cellular analysis by a pathologist, and culture and sensitivity (in rare cases if indicated). Intravesicular bladder pressure measurement using a manometer-urinary catheter system approximates the IAP when there is concern for organ hypoperfusion and compartment syndrome. RESULTS: Abdominocentesis can be performed with and without the use of ultrasound guidance. Intravesicular bladder pressure measurement is used to diagnose and trend IAP values before and after treatments are performed. CLINICAL RELEVANCE: Abdominocentesis is a simple and safe technique that all small animal clinicians should be comfortable performing. Effusion sampling can guide further diagnostics and treatments. Measurement of IAP is simple and requires no specialized equipment.

Intraperitoneal pharmacokinetics of systemic oxaliplatin, 5-fluorouracil and bevacizumab in patients with colorectal peritoneal metastases.

BACKGROUND: Peritoneal metastases (PM) commonly occur in colorectal cancer patients. Systemic chemotherapy yields poor outcomes for these patients. It is hypothesised that traditional systemic chemotherapy is not very effective for this patient population. This study investigates to what extent systemic anti-cancer therapy crosses the peritoneal barrier. METHODS: In a Phase I study, eighteen patients received systemic oxaliplatin, 5-FU, and bevacizumab. Plasma and peritoneal fluid samples were collected to measure drug concentrations. A non-compartmental analysis determined the Area Under the Curve (AUC) for oxaliplatin and 5-FU in both matrices. Intraperitoneal (IP) and intravenous (IV) exposure ratios were calculated, along with the bevacizumab concentration IP/IV ratio. The relationship between tumour load and IP/IV ratios and the correlation between the IP/IV ratios of different treatments were assessed statistically. RESULTS: A total of 438 5-FU samples and 578 oxaliplatin samples were analysed in plasma and peritoneal fluid. Bevacizumab was quantified with 17 measurements in plasma and 15 measurements IP. Median IP/IV ratios were 0.143, 0.352 and 0.085 for 5-FU, oxaliplatin and bevacizumab, respectively. Oxaliplatin exhibited a longer IP half-life than 5-FU. A correlation was found between oxaliplatin and bevacizumab IP/IV ratios (R=0.69, p=0.01). No statistical correlations were found between the other investigated drugs. CONCLUSIONS: Our findings indicate that only a small percentage of systemically administered anti-cancer treatment reaches the IP cavity, questioning their efficacy against PM. This strengthens the hypothesis for repeated intraperitoneal chemotherapy to reach adequate anti-cancer drug levels.

Application of metagenomic next-generation sequencing in optimizing the diagnosis of ascitic infection in patients with liver cirrhosis.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) is an emerging technique for the clinical diagnosis of infectious disease that has rarely been used for the diagnosis of ascites infection in patients with cirrhosis. This study compared mNGS detection with conventional culture methods for the on etiological diagnosis of cirrhotic ascites and evaluated the clinical effect of mNGS. METHODS: A total of 109 patients with ascites due to cirrhosis were included in the study. We compared mNGS with conventional culture detection by analyzing the diagnostic results, pathogen species and clinical effects. The influence of mNGS on the diagnosis and management of ascites infection in patients with cirrhosis was also evaluated. RESULTS: Ascites cases were classified into three types: spontaneous bacterial peritonitis (SBP) (16/109, 14.7%), bacterascites (21/109, 19.3%) and sterile ascites (72/109, 66.1%). In addition, 109 patients were assigned to the ascites mNGS-positive group (80/109, 73.4%) or ascites mNGS-negative group (29/109, 26.6%). The percentage of positive mNGS results was significantly greater than that of traditional methods (73.4% vs. 28.4%, P < 0.001). mNGS detected 43 strains of bacteria, 9 strains of fungi and 8 strains of viruses. Fourteen bacterial strains and 3 fungal strains were detected via culture methods. Mycobacteria, viruses, and pneumocystis were detected only by the mNGS method. The mNGS assay produced a greater polymicrobial infection rate than the culture method (55% vs. 16%). Considering the polymorphonuclear neutrophil (PMN) counts, the overall percentage of pathogens detected by the two methods was comparable, with 87.5% (14/16) in the PMN ≥ 250/mm3 group and 72.0% (67/93) in the PMN < 250/mm3 group (P > 0.05). Based on the ascites PMN counts combined with the mNGS assay, 72 patients (66.1%) were diagnosed with ascitic fluid infection (AFI) (including SBP and bacterascites), whereas based on the ascites PMN counts combined with the culture assay, 37 patients (33.9%) were diagnosed with AFI (P < 0.05). In 60 (55.0%) patients, the mNGS assay produced positive clinical effects; 40 (85.7%) patients had their treatment regimen adjusted, and 48 patients were improved. The coincidence rate of the mNGS results and clinical findings was 75.0% (60/80). CONCLUSIONS: Compared with conventional culture methods, mNGS can improve the detection rate of ascites pathogens, including bacteria, viruses, and fungi, and has significant advantages in the diagnosis of rare pathogens and pathogens that are difficult to culture; moreover, mNGS may be an effective method for improving the diagnosis of ascites infection in patients with cirrhosis, guiding early antibiotic therapy, and for reducing complications related to abdominal infection. In addition, explaining mNGS results will be challenging, especially for guiding the treatment of infectious diseases.

Peritoneal Tumour DNA in Peritoneal Fluid: Emerging Tool for Peritoneal Metastasis Detection.

The prognostic significance of positive peritoneal cytology still varied between cancer types and geographical origin. However, because of the lack of sensitivity of this biomarker, conventional cytology is not routinely performed in every country. Here, we wanted to test a new biomarker, peritoneal tumour DNA, using NGS technique, in order to compare it with the historical one, in patients having peritoneal metastases of gastrointestinal or ovarian cancer.

Can nematode infection cause internal bleeding in dogs? A case of Dirofilaria immitis infection in cavitary fluids.

A 9-year-old dog was presented with weight loss, respiratory effort, and an enlarged abdomen. Imaging studies and exploratory surgery showed pulmonary and splenic masses and bi-cavitary effusion, later classified as hemorrhage. Cytology of the peritoneal and pleural fluids also revealed several microfilariae. Immunologic and molecular analyses confirmed Dirofilaria immitis infection and histopathology of the spleen indicated a cavernous endothelial proliferation with undefined etiology (hemangiosarcoma vs reaction to parasite infestation). The nematode larvae are speculated to have entered body cavities via erratic migration or via hemorrhage and visceral lesions to be related to parasitism. Nematode infection should be considered as a differential diagnosis for internal bleeding of undetermined origin.

Proteomic profiles of peritoneal fluid-derived small extracellular vesicles correlate with patient outcome in ovarian cancer.

Cancer-derived small extracellular vesicles (sEVs) are capable of modifying the tumor microenvironment and promoting tumor progression. Ovarian cancer (OvCa) is a lethal malignancy that preferentially spreads through the abdominal cavity. Thus, the secretion of such vesicles into the peritoneal fluid could be a determinant factor in the dissemination and behavior of this disease. We designed a prospective observational study to assess the impact of peritoneal fluid-derived sEVs (PFD-sEVs) in OvCa clinical outcome. For this purpose, 2 patient cohorts were enrolled: patients with OvCa who underwent a diagnostic or cytoreductive surgery and nononcological patients, who underwent abdominal surgery for benign gynecological conditions and acted as the control group. Systematic extraction of PFD-sEVs from surgical samples enabled us to observe significant quantitative and qualitative differences associated with cancer diagnosis, disease stage, and platinum chemosensitivity. Proteomic profiling of PFD-sEVs led to the identification of molecular pathways and proteins of interest and to the biological validation of S100A4 and STX5. In addition, unsupervised analysis of PFD-sEV proteomic profiles in high-grade serous ovarian carcinomas (HGSOCs) revealed 2 clusters with different outcomes in terms of overall survival. In conclusion, comprehensive characterization of PFD-sEV content provided a prognostic value with potential implications in HGSOC clinical management.

Improving diagnostic accuracy of identifying gastric cancer patients with peritoneal metastases: tumor-guided cell-free DNA analysis of peritoneal fluid.

Detection of peritoneal dissemination (PD) in gastric cancer (GC) patients remains challenging. The feasibility of tumor-guided cell-free DNA (cfDNA) detection in prospectively collected peritoneal fluid (ascites and peritoneal lavage) was investigated and compared to conventional cytology in 28 patients. Besides conventional cytology, next generation sequencing was performed on primary tumor DNA and cell-free DNA from peritoneal fluid. Patients were retrospectively grouped into: a positive group (with PD) and a negative group (without PD). Detectable mutations were found in the primary tumor of 68% (n = 19). Sensitivity of PD detection by tumor-guided cfDNA analysis was 91%, compared to 64% by conventional cytology. Within the positive group (n = 11), tumor-guided cfDNA was detected in all patients with ascites samples (4/4, 100%) and in 86% (6/7) of the lavage samples, opposed to 4/4 (100%) patients with ascites and 43% (3/7) with lavage by conventional cytology. Within the negative group (n = 8), conventional cytology was negative for all samples. In two patients, tumor-guided cfDNA was detected in peritoneal lavage fluid. Interestingly, these 2 patients developed PD within 6 months, suggesting a prognostic value of tumor-guided cfDNA detection. This study showed that tumor-guided cfDNA detection in peritoneal fluids of GC patients is feasible and superior to conventional cytology in detecting PD.