Cystic lymphangioma of the lesser omentum in an adult patient.

INTRODUCTION: Lymphangiomas belong to the group of benign vascular tumors that originate in the lymphatic tissue. Up to 90% of cases manifest in children before the second year of life. In adults, their presence is very rare. In most cases, they are located in the head, neck and axilla. Intra-abdominal lymphangiomas are very rare and represent less than 1% of all cases. CASE REPORT: The authors present the case of a 64-year-old female patient diagnosed with an intra-abdominal cystic lesion following a routine examination. A CT scan of the abdomen confirmed a cystic lesion located in the lesser omentum between the left lobe of the liver and the lesser curvature of the stomach. The patient was scheduled for laparoscopic exstirpation of the lesion. Histological examination confirmed the clinical diagnosis of cystic lymphangioma of the lesser omentum. CONCLUSION: The etiopathogenesis of lymphangiomas remains unclear. Despite the fact that they are benign tumors, lymphangiomas tend to have an infiltrative pattern of growth, invading surrounding structures. The majority of cases are asymptomatic and the diagnosis is incidental. The gold standard in treatment remains complete surgical extirpation with microscopically negative margins.

Omentum pregnancy resulting in severe hemoperitoneum: Lessons learned from a review of the literature along with a case report.

Abdominal pregnancies are a rare form of ectopic pregnancy with omentum pregnancies being even rarer. Ectopic pregnancy should be diagnosed and terminated early to prevent the risk of harm to the mother. This case report describes a rare case of omentum pregnancy with severe hemoperitoneum. The patient had not visited a doctor until she failed to menstruate for 3 months, by which point she had developed severe hypogastralgia. The patient was diagnosed with a ruptured ectopic pregnancy after ultrasonography. The omentum pregnancy was complicated by severe hemoperitoneum, which was confirmed by emergency laparotomy. The patient was treated successfully with fetal extraction and partial omentectomy. Ultrasound examination in early pregnancy is essential to detect and treat ectopic pregnancies as early as possible, as surgery is usually required for abdominal pregnancies. Prompt treatment of ectopic pregnancies is critical, as an omentum pregnancy is dangerous and may result in severe intraperitoneal bleeding.

Comparative assessment of the capability of machine learning-based radiomic models for predicting omental metastasis in locally advanced gastric cancer.

The study aims to investigate the predictive capability of machine learning algorithms for omental metastasis in locally advanced gastric cancer (LAGC) and to compare the performance metrics of various machine learning predictive models. A retrospective collection of 478 pathologically confirmed LAGC patients was undertaken, encompassing both clinical features and arterial phase computed tomography images. Radiomic features were extracted using 3D Slicer software. Clinical and radiomic features were further filtered through lasso regression. Selected clinical and radiomic features were used to construct omental metastasis predictive models using support vector machine (SVM), decision tree (DT), random forest (RF), K-nearest neighbors (KNN), and logistic regression (LR). The models' performance metrics included accuracy, area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In the training cohort, the RF predictive model surpassed LR, SVM, DT, and KNN in terms of accuracy, AUC, sensitivity, specificity, PPV, and NPV. Compared to the other four predictive models, the RF model significantly improved PPV. In the test cohort, all five machine learning predictive models exhibited lower PPVs. The DT model demonstrated the most significant variation in performance metrics relative to the other models, with a sensitivity of 0.231 and specificity of 0.990. The LR-based predictive model had the lowest PPV at 0.210, compared to the other four models. In the external validation cohort, the performance metrics of the predictive models were generally consistent with those in the test cohort. The LR-based model for predicting omental metastasis exhibited a lower PPV. Among the machine learning algorithms, the RF predictive model demonstrated higher accuracy and improved PPV relative to LR, SVM, KNN, and DT models.

Evidence That Peripheral Leptin Resistance in Omental Adipose Tissue and Liver Correlates with MASLD in Humans.

Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic dysfunction-associated steatotic liver disease (MASLD) is unclear. This study evaluated the contribution of the leptin axis to MASLD in humans. Forty-three participants, mostly female (86.04%), who underwent cholecystectomy were biopsied. Of the participants, 24 were healthy controls, 8 had MASLD, and 11 had metabolic dysfunction-associated steatohepatitis (MASH). Clinical and biochemical data and the gene expression of leptin, leptin receptor (LEPR), suppressor of cytokine signaling 3 (SOCS3), sterol regulatory element-binding transcription factor 1 (SREBF1), stearoyl-CoA desaturase-1 (SCD1), and patatin-like phospholipase domain-containing protein 2 (PNPLA2), were determined from liver and adipose tissue. Higher serum leptin and LEPR levels in the omental adipose tissue (OAT) and liver with MASH were found. In the liver, LEPR was positively correlated with leptin expression in adipose tissue, and SOCS3 was correlated with SREBF1-SCD1. In OAT, SOCS3 was correlated with insulin resistance and transaminase enzymes (p < 0.05 for all. In conclusion, we evidenced the correlation between the peripheral leptin resistance axis in OAT-liver crosstalk and the complications of MASLD in humans.

Omental metastases in patients with pseudomyxoma peritonei or colorectal peritoneal metastases - is routine omentectomy justified?

BACKGROUND: The greater omentum is routinely resected during cytoreductive surgery (CRS), but few studies have analyzed the rationale behind this. This study aimed to assess the prevalence of omental metastases (OM) and the correlation between macroscopically suspected and microscopically confirmed OM, in patients with pseudomyxoma peritonei (PMP) or colorectal peritoneal metastases (PM). METHOD: All patients without previous omentectomy, treated with initial CRS and hyperthermic intraperitoneal chemotherapy for PMP or colorectal PM, at Uppsala University Hospital in 2013-2021, were included. Macroscopic OM in surgical reports was compared with histopathological analyses. RESULTS: In all, 276 patients were included. In those with PMP, 112 (98%) underwent omentectomy and 67 (59%) had macroscopic suspicion of OM. In 5 (4%) patients, the surgeon was uncertain. Histopathology confirmed OM in 81 (72%). In patients with macroscopic suspicion, 96% had confirmed OM (positive predictive value, PPV). In patients with no suspicion, 24% had occult OM (negative predictive value, NPV = 76%). In patients with colorectal PM, 156 (96%) underwent omentectomy and 97 (60%) had macroscopic suspicion. For 5 (3%) patients, the surgeon was uncertain. OM was microscopically confirmed in 90 (58%). PPV was 85% and NPV was 89%. The presence of OM was a univariate risk factor for death in PMP (HR 3.62, 95%CI 1.08-12.1) and colorectal PM (HR 1.67, 95%CI 1.07-2.60), but not in multivariate analyses. CONCLUSION: OM was common and there was a high risk of missing occult OM in both PMP and colorectal PM. These results support the practice of routine omentectomy during CRS.

Primary segmental omental torsion, mimicking acute appendicitis.

Primary segmental omental torsion (PSOT) is a very rare cause of acute abdominal pain, and it may often imitate the clinical picture of acute appendicitis. In instances of acute abdominal pain without anorexia, nausea, and vomiting, omental torsion should be included in the differential diagnosis. Any misdiagnosis may lead to major complications such as intraabdominal abscesses and adhesions. A 63-year-old overweight man with a body mass index (BMI) of 41 Kg/m2 presented to the emergency department on a remote island with acute abdominal pain. His medical history included type 2 diabetes mellitus managed with insulin, essential hypertension, osteoarthritis, and no previous abdominal operations. He reported a sharp pain originating in the epigastrium and the right hypochondrium that started five days prior. Physical examination revealed rebound tenderness and guarding across the abdomen with a positive McBurney sign. However, the patient did not report vomiting and was not nauseous. Vital signs were as follows: blood pressure 116/56 mmHg, heart rate 98 beats/min, respiratory rate 19 breaths/min, and a temperature of 38.2 0C. Laboratory results showed a white blood cell count of 10.6, neutrophils of 8.11, C-reactive protein (CRP) 74 mg/l, haemoglobin11.6 g/dl, and hematocrit 36.9%. Due to the absence of a radiographer at the hospital during that period, no imaging investigations were conducted. Diagnostic laparoscopy demonstrated diffused hemoperitoneum and necrotic mass at the site of the hepatic flexure. Initially suspected to be an advanced colon cancer, the decision was made to proceed with open surgery. The necrotic segment of the omentum was found at the right superior point of attachment of the omentum to the hepatic flexure. Consequently, the necrotic segment of the omentum was resected. A thorough investigation of the abdominal cavity did not detect any other abnormalities or pathologies. The patient recovered uneventfully and was transferred to the surgical ward. Torsion of the omentum is a very rare cause of acute abdominal pain. This case highlights the necessity of considering PSOT in the differential diagnosis of acute abdominal pain, especially in cases where symptoms are suggestive of appendicitis but diagnostic findings are negative.

Malignant Extrarenal Rhabdoid tumor derived from the greater omentum: A case report and literature review.

BACKGROUND: Malignant extrarenal rhabdoid tumor (MERT) is a rare and highly metastatic tumor, which is more than 75% of patients dying within 6 months of initial diagnosis, and it often leads to misdiagnosis and delayed treatment. CASE: This paper reports a 16-year-old girl who presented with the chief complaint of acute abdominal pain. She underwent laparoscopic exploration and excisional biopsy, then pathological examination and immunohistochemistry revealed "extrarenal malignant rhabdomyoma." One month after operation, she died of intra-abdominal hemorrhage and multiple organ dysfunction. CONCLUSION: MERT were often misdiagnosed and had a poor prognosis. The surgery and chemotherapy are usually beneficial to prolong the survival time of patients with MERT.

Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report.

BACKGROUND: The greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient. CASE PRESENTATION: A 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up. DISCUSSION AND CONCLUSION: We encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

Vagus nerve signal has an inhibitory influence on the development of peritoneal metastasis in murine gastric cancer.

The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 105 YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

A randomized controlled trial to compare short-term outcomes following infragastric and infracolic omentectomy at the time of primary debulking surgery for epithelial ovarian cancer with normal-appearing omentum.

BACKGROUND: Omentectomy is an important procedure in surgery for epithelial ovarian cancer, but the scope of omentectomy is not recommended in the guidelines. This study was performed to evaluate the benefits and risks of infragastric omentectomy in patients with epithelial ovarian cancer. METHODS: This trial is a single center prospective study. Primary epithelial ovarian cancer patients with normal-appearing omentum were randomly assigned to either the control or experimental group and underwent infracolic or infragastric omentectomy, respectively. The primary endpoint was progression-free survival. This trial is registered on Chinese clinical trial registry site (ChiCTR1800018771). RESULTS: A total of 106 patients meeting the inclusion criteria for ovarian cancer were included during the study period. Of these, 53 patients underwent infracolic omentectomy, whereas 53 patients received infragastric omentectomy. Multivariate analysis revealed that infragastric omentectomy could improve the detection rate of omental metastases (OR: 6.519, P = 0.005). Infragastric omentectomy improved progression-free survival significantly for those cases with higher than stage IIB disease (HR: 0.456, P = 0.041). Based on the short-term results, infragastric omentectomy did not cause more perioperative complications. CONCLUSIONS: Compared with infracolic omentectomy, infragrastric omentectomy may be a more appropriate surgical procedure for stage IIB-IIIC epithelial ovarian cancer patients with normal-appearing omentum.

Omental Preadipocytes Stimulate Matrix Remodeling and IGF Signaling to Support Ovarian Cancer Metastasis.

Ovarian cancer can metastasize to the omentum, which is associated with a complex tumor microenvironment. Omental stromal cells facilitate ovarian cancer colonization by secreting cytokines and growth factors. An improved understanding of the tumor-supportive functions of specific cell populations in the omentum could identify strategies to prevent and treat ovarian cancer metastasis. Here, we showed that omental preadipocytes enhance the tumor initiation capacity of ovarian cancer cells. Secreted factors from preadipocytes supported cancer cell viability during nutrient and isolation stress and enabled prolonged proliferation. Coculturing with preadipocytes led to the upregulation of genes involved in extracellular matrix (ECM) organization, cellular response to stress, and regulation of insulin-like growth factor (IGF) signaling in ovarian cancer cells. IGF1 induced ECM genes and increased alternative NF-κB signaling by activating RelB. Inhibiting the IGF1 receptor initially increased tumor omental adhesion but decreased the growth of established preadipocyte-induced subcutaneous tumors as well as established intraperitoneal tumors. Together, this study shows that omental preadipocytes support ovarian cancer progression, which has implications for targeting metastasis. Significance: Omental preadipocyte-mediated IGF1 signaling promotes ovarian cancer tumorigenesis and metastasis via extracellular matrix remodeling, revealing a role for preadipocytes in regulating ovarian cancer progression and highlighting potential therapeutic targets for metastatic disease.

Morphological Characteristics of the Results of Experimental Modeling of Septic Peritonitis

SUMMARY: Experimental studies devoted to the study of the mechanisms of the pathogenesis of acute peritonitis and the development of new methods of medical and surgical treatment are becoming increasingly relevant. Today, experimental medicine knows many different ways to modeling septic peritonitis and eliminate it, but the role of the local immune system is underestimated, whereas it takes a direct part in inflammation. The objective of our work to study morphological features of results of experimental modeling of septic peritonitis in white rats. The study included 15 sexually mature white male rats weighing 276.75±6.56 grams. A simulation of septic peritonitis was performed by perforating the upper part of the cecum with four punctures with a G16 injection needle. As a result of the experiment, after examination of the peritoneal cavity, all 15 animals were diagnosed with omentum tamponade of perforated damage to the caecum. In 11 cases, the perforated wall of the caecum was covered by the greater omentum (73.34 %), and in the other 4 animals, tamponade was performed by one of the epididymal omentum (26.66 %). The initial stage of tamponade with the greater or epididymal omentums of a perforated caecum begins on the first day of the experiment and consists of tight interstitial consolidation between them, as well as in the invasion of blood vessels from the omentum side to the focus of infection, which ensure the delivery of the appropriate immunocompetent cells. As a result of this process, intensive lymphoid infiltrates are formed in this area, as well as the growth of adipose tissue, which isolates the inflammatory focus from the peritoneal cavity with a thick layer.

Las investigaciones experimentales dedicadas al estudio de los mecanismos de patogénesis de la peritonitis aguda y el desarrollo de nuevos métodos de tratamiento médico y quirúrgico son cada vez más relevantes. Hoy en día, la medicina experimental conoce muchas formas diferentes de modelar la peritonitis séptica y eliminarla, pero se subestima el papel del sistema inmunológico local, mientras que él participa directamente en la inflamación. El objetivo de nuestro trabajo fue estudiar las características morfológicas de los resultados del modelado experimental de peritonitis séptica en ratas blancas. El estudio incluyó 15 ratas macho blancas, sexualmente maduras que pesaban 276,75 ± 6,56 gramos. Se realizó una simulación de peritonitis séptica perforando la parte superior del ciego con cuatro punciones con una aguja de inyección G16. Como resultado del experimento, después del examen de la cavidad peritoneal, a los 15 animales se les diagnosticó taponamiento del omento o lesión perforada del ciego. En 11 casos, la pared perforada del ciego fue recubierta por el omento mayor (73,34 %), y en los otros 4 animales el taponamiento se realizó por uno de los epidídimos (26,66 %). La etapa inicial del taponamiento con omento mayor o epidídimo de un ciego perforado comienza el primer día del experimento y consiste en una estrecha consolidación intersticial entre ellos, así como en la invasión de los vasos sanguíneos desde el lado del omento hasta el foco de infección, que aseguran la entrega de las células inmunocompetentes apropiadas. Como resultado de este proceso, se forman intensos infiltrados linfoides en esta zona, así como el crecimiento de tejido adiposo, que aísla el foco inflamatorio de la cavidad peritoneal con una gruesa capa.

Neuroendocrine tumour of the lesser omentum.

A man in his early 20s presented to us in the outpatient department with a history of diarrhoea for 4 months. Investigations revealed elevated serum chromogranin levels and an intensely avid lesion in the gastrohepatic ligament in Gallium DOTATATE positron emission tomography (PET). The tumour was excised laparoscopically, and no other lesions were seen. The patient improved clinically and had a normal serum chromogranin level postoperatively. He is currently much improved at the 1year follow-up. We did an extensive workup to look for a primary tumour. It was concluded that it was a de novo tumour arising from the lesser sac. The recommended investigations in case of neuroendocrine tumour (NET) with unknown primary include blood investigations to look for the functional status of the tumour, histopathological examination, including immunohistochemistry, and radiological imaging, which must include a Gallium DOTATATE PET. An isolated NET of the lesser sac has not been reported in the literature.

A protocol for selection in mice of highly metastatic ovarian cancer cell with omental tropism.

Preclinical models mimicking spontaneous omental metastasis from ovarian cancer (OC) can benefit the study of anti-metastatic therapies for OC patients. Here, we present a protocol to establish a highly metastatic (HM) mouse model with omental tropism by in vivo selection. We describe the processes of implanting OC cells in the ovaries of mice and obtaining HM sublines from their omental metastases. HM cells can metastasize from the ovary to the omentum within 2 weeks. For complete details on the use and execution of this protocol, please refer to Ying et al.1.

Omental Hibernoma Revealed by 18 F-FDG PET/CT.

ABSTRACT: Hibernomas are "pseudolipomas" originating from remnants of fetal brown adipose tissue. These rare benign tumors may occur throughout the body but most commonly in the thigh, shoulder, back, and neck, and are rarely found in the abdominal cavity, retroperitoneum, breast, bones, scrotum, and perirectum. We present a case of a 58-year-old woman with a known mediastinal mass, who was incidentally found to have a very FDG-avid fat-containing lesion in the omentum abutting the stomach. Subsequent endoscopic ultrasound-guided fine-needle aspiration confirmed hibernoma. The review of the literature shows the location is very unusual.

CT and MR imaging of the greater omentum: Pictorial essay.

The greater omentum is a unique anatomical structure that serves a critical function in the containment of inflammatory and infectious processes within the abdominal cavity. It is also a common site of involvement by metastases, as well as the primary location for various pathologic lesions of clinical significance. Its fibroadipose composition, large size, and position in the most anterior aspect of abdomen allow accurate visualization of the greater omentum on CT and MR images. Careful evaluation of the greater omentum can provide important clues to the diagnosis of the underlying abdominal disorder. The aim of this article is to present the normal appearance of the greater omentum, and the wide spectrum of its pathological features as demonstrated on CT and MRI of the abdomen.

The concept of developmental anatomy: the greater omentum should be resected in right-sided colon cancer?

BACKGROUND: The greater omentum is derived from the foregut, and the right hemicolon is derived from the midgut based on developmental anatomy. This study aimed to investigate whether the greater omentum should be resected in laparoscopic complete mesocolic excision based on developmental anatomy for right-sided colon cancer. METHODS: A total of 183 consecutive patients with right-sided colon cancer were recruited in this study between February 2020 and July 2022. Ninety-eight patients underwent standard laparoscopic complete mesocolic excision surgery (CME group). The presence of isolated tumor cells and micrometastases was detected in resected greater omentum by the HE staining and immunohistochemistry analysis. Based on developmental anatomy, laparoscopic CME surgery with greater omentum preservation (DACME group) was proposed and performed on 85 right-sided colon cancer patients. To overcome selection bias, we performed a 1:1 match between two groups using four variables: age, sex, BMI, and ASA scores. RESULTS: No isolated tumor cells and micrometastases were found in the resected greater omentum specimen in the CME group. After the propensity score, 81 pairs were balanced and analyzed. Patients in the DACME group showed shorter operative time (194.9 ± 16.4 min vs.201.5 ± 11.5 min, p = 0.002), less blood loss (23.5 ± 24.7 ml vs.33.6 ± 26.3 ml, p = 0.013), and the shorter hospital stays (9.6 ± 1.7 days vs.10.3 ± 2.0 days, p = 0.010) compared with patients in the CME group. In addition, patients in the DACME group had a lower incidence of postoperative complications (4.9% vs.14.8%, p = 0.035) than patients in the CME group. CONCLUSION: The greater omentum should be preserved during right-sided colon cancer surgery, laparoscopic CME surgery based on developmental anatomy is technically safe and feasible for right-sided colon cancer.

Omental cancer-associated fibroblast-derived exosomes with low microRNA-29c-3p promote ovarian cancer peritoneal metastasis.

Ovarian cancer (OC) is characterized by frequent widespread peritoneal metastasis. Cancer-associated fibroblasts (CAFs) represent a critical stromal component of metastatic niche and promote omentum metastasis in OC patients. However, the role of exosomes derived from omental CAFs in metastasis remains unclear. We isolated exosomes from primary omental normal fibroblasts (NFs) and CAFs from OC patients (NF-Exo and CAF-Exo, respectively) and assessed their effect on metastasis. In mice bearing orthotopic OC xenografts, CAF-Exo treatment led to more rapid intraperitoneal tumor dissemination and shorter animal survival. Similar results were observed in mice undergoing intraperitoneal injection of tumor cells. Among the miRNAs downregulated in CAF-Exo, miR-29c-3p in OC tissues was associated with metastasis and survival in patients. Moreover, increasing miR-29c-3p in CAF-Exo significantly weakened the metastasis-promoting effect of CAF-Exo. Based on RNA sequencing, expression assays, and luciferase assays, matrix metalloproteinase 2 (MMP2) was identified as a direct target of miR-29c-3p. These results verify the significant contribution of exosomes from omental CAFs to OC peritoneal metastasis, which could be partially due to the relief of MMP2 expression inhibition mediated by low exosomal miR-29c-3p.