Peritoneal Tumor Research Articles

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC): an option for patients (pts) with uncommon histologies (UH)?

Background: Peritoneal carcinomatosis (PC) is an adverse prognostic factor for several cancers. CRS/HIPEC is considered a standard option for primary peritoneal tumors as well as ovarian cancer, and can be considered in selected gastric and colorectal cancer patients. The safety and efficacy of CRS/HIPEC have not been fully evaluated in pts beyond these indications.

Incidental Multifocal Peritoneal Adenomatoid Tumors Presenting Intra Operatively as Possible Metastatic Disease in a 73 Year Old Woman

Adenomatoid tumour is a benign entity which occurs most commonly in the female and male genital tract. In females they cannot be distinguished clinically or radiologically from other entities such as leiomyoma; histology is required and intra-operative frozen section can be considered. Resection can be challenging when the growth pattern is diffuse.

The Importance of Metastatic Papillary Serous Carcinoma in Cases of High-grade Encapsulated Papillary Carcinoma of the Breast: An Extremely Rare Case and a Possible Pitfall

Background: Encapsulated papillary carcinoma (EPC) of the breast has a favorable prognosis. High-grade EPCs, triple-negative or HER-2-positive, are dealt with as invasive carcinomas. Breast metastasis associated with serous carcinoma is a late-stage event. The discrimination between the two diagnoses can be very challenging.Case Presentation: A 79-year-old woman with a history of well controlled high-grade serous papillary carcinoma of the peritoneum went through a total left mastectomy and sentinel lymph node biopsy (SLNB) because of an invasive carcinoma in her left breast. In the lab, a peripheral nodular mass of 4cm was found. Microscopically, large intracystic papillary stalks, with high nuclear grade, surrounded by collagenous tissue were identified compatible with invasive encapsulated papillary carcinoma with positive estrogen receptor. A few months later, the patient was diagnosed with a supraclavicular cervical mass, which on FNB was indicative of metastatic serous papillary carcinoma. Immunohistochemical stains were similar in breast and previously treated peritoneal tumor showed ER+, PAX8+, p53+ (wild type) and high Ki-67 (80%). WT1 was positive only in peritoneal serous carcinoma. GATA-3 was weakly, scarcely expressed in both specimens. The findings pointed to metastatic SPC in the breast, mimicking primary carcinoma of the EPC type. Conclusion: Pathology of breast metastases and distincion from primary breast cancers is done by a combination of morphological and IHC features. In our case, the lack of clinical history, the type of surgical approach (mastectomy and SLNB), the solitary lesion, the EPC pattern of growth and the diffuse ER+ staining, were indicative of primary breast lesion. Various morphologic growth patterns of metastatic PSC have been described, among which EPC-like needs to be considered.

Histidine-rich calcium binding protein promotes gastric cancer cell proliferation, migration, invasion and epithelial-mesenchymal transition through Raf/MEK/ERK signaling.

Histidine-rich calcium binding protein (HRC) is a new type of Ca2+ homeostasis regulator, which acts as a nonnegligible role in regulating intracellular calcium homeostasis. Here, we demonstrated that HRC expression was upregulated in human gastric cancer (GC) samples, and its expression level was closely correlated with the overall survival (OS) rate of GC patients and the malignant potential of GC cell lines. Knockdown of HRC inhibited migration, invasion, and proliferation of GC cell lines in vitro, while HRC overexpression promoted GC cell migration, invasion, and proliferation in vitro, as well as the growth of subcutaneous tumors and peritoneal tumors in vivo. In terms of the mechanism, knockdown of HRC reduced the intracellular calcium ion level and the CaM protein level. Through cell function experiments, we found that HRC regulated the Raf/MEK/ERK pathway through Ca2+/CaM signaling and ultimately affected the epithelial‑mesenchyme transition (EMT) of GC. In summary, we revealed that HRC represents a potential target for GC treatment.

Effect of Systemic or Intraperitoneal Administration of Anti-PD-1 Antibody for Peritoneal Metastases from Gastric Cancer.

Programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) blockade therapy is widely used for the treatment of patients with metastatic gastric cancer (GC). However, it is unclear how PD-1 antibodies affect the local immunity related to the growth of peritoneal metastases (PM). The clinical efficacy of PD-1/PD-L1 inhibitors against PM from GC has not been clearly determined. We established a highly metastatic subclone of murine GC cells to the peritoneum, YTN16P, by in vivo selection and evaluated the effects of intravenous (IV) or intraperitoneal (IP) administration of anti-PD-1 antibody on PM in immunocompetent mice model. Phenotypes of immune cells in the spleen and peritoneal metastatic lesions were determined with flow cytometry and immunohistochemistry. IP inoculation of YTN16P (1×106) resulted in multiple mesenteric metastases after 3 weeks. IV and IP administration of anti-PD-1mAb reduced the number of metastases to the mesentery by 30~40% compared with isotype controls. However, no differences were observed depending on the route of administration. Although splenocyte phenotypes were not altered, the densities of CD8(+) T cells in peritoneal tumors were significantly increased, whereas those of Gr-1(+) myeloid derived suppressor cells (MDSC) were significantly reduced in mice treated with anti-PD-1 mAb. PD-1 blockade therapy remodels the cellular immune composition of peritoneal tumors, which can partially suppress the PM from GC regardless of the route of administration. Adding anti-PD-1 antibody to chemotherapeutic regimens may enhance their anti-tumor effects against PM, which can lead to the prolongation of survival of patients with GC with peritoneal involvement.

Management of Patients with Malignant Peritoneal Mesothelioma: The Evolving Role of Surgery and Immunotherapy

Malignant peritoneal mesothelioma, a neoplastic process that arises from the peritoneal membranes and presents as a diffuse malignant process, has an incidence of approximately 400-600 new cases annually in the United States. Systemic chemotherapy regimens, like the combination of cisplatin and pemetrexed, have response rates of approximately 25% in peritoneal mesothelioma. Due to chemotherapy’s poor response rates, the first line approach to treating malignant peritoneal mesothelioma over the last 30 years has been surgical resection with regional intra-peritoneal chemotherapy in appropriately selected patients. Hyperthermic intraoperative intraperitoneal perfusion with chemotherapy with cisplatin or mitomycin c for 90 to 120 minutes is the most commonly reported type of regional chemotherapy that is administered during surgical cytoreduction. Favorable prognostic factors for patient outcomes after cytoreduction and hyperthermic intraperitoneal perfusion with chemotherapy tend to be favorable operative characteristics (lower peritoneal cancer index, better complete cytoreduction score), less aggressive tumor characteristics (epithelioid histology, low Ki-67, well-differentiated), and other patient characteristics (young, female, fewer comorbidities). Recently, there has been considerable interest in the utility of immune checkpoint inhibitors either alone or in combination with chemotherapy for patients with mesothelioma. Data demonstrate that programmed death-ligand 1 may be highly expressed in a large proportion of malignant peritoneal mesothelioma tumors and therefore the evaluation of checkpoint blockade in this patient population is a high clinical priority.

Genomic Landscape of Pleural and Peritoneal Mesothelioma Tumors

Genomic Landscape of Pleural and Peritoneal Mesothelioma Tumors

The tumor immune microenvironment in peritoneal carcinomatosis.

One in four patients with colorectal cancer, 40% of gastric cancer patients, and 60% of ovarian cancer patients will develop peritoneal metastases (PM) in the course of their disease. The outcome of patients with widespread PM remains poor with currently available treatments. Despite the relatively common occurrence of PM, little is known on the pathophysiology that drives the peritoneal metastatic cascade. It is increasingly recognized that the stromal components of the peritoneal microenvironment play an essential role in tumor progression. However, little is known about the specific interactions and components of the peritoneal tumor microenvironment, particularly with respect the immune cell population. We summarize the current knowledge of the tumor immune microenvironment (TIME) in peritoneal metastases originating from the three most common origins: ovarian, gastric, and colorectal cancer. Clearly, the TIME is highly heterogeneous and its composition and functional activity differ according to tumor type and, within the same patient, according to anatomical location. The TIME in PM remains to be explored in detail, and further elucidation of their immune contexture may allow biology driven design of novel immune modulating or immune targeting therapies.

PET imaging and treatment of pancreatic cancer peritoneal carcinomatosis after subcutaneous intratumoral administration of a novel oncolytic virus, CF33-hNIS-antiPDL1

Peritoneal carcinomatosis of gastrointestinal malignancies remains fatal. CF33-hNIS-antiPDL1, a chimeric orthopoxvirus expressing the human sodium iodide symporter (hNIS) and anti-human programmed death-ligand 1 antibody, has demonstrated robust preclinical activity against pancreatic adenocarcinoma (PDAC). We investigated the ability of CF33-hNIS-antiPDL1 to infect, help detect, and kill peritoneal tumors following intratumoral (i.t.) injection of subcutaneous (s.c.) tumors in vivo. Human PDAC AsPC-1-ffluc cells were inoculated in both the s.c. space and the peritoneal cavity of athymic mice. After successful tumor engraftment, s.c. tumors were injected with CF33-hNIS-antiPDL1 or PBS. We assessed the ability of CF33-hNIS-antiPDL1 to infect, replicate in, and allow the imaging of tumors at both sites (immunohistochemistry [IHC] and 124I-based positron emission tomography/computed tomography [PET/CT] imaging), tumor burden (bioluminescence imaging), and animal survival. IHC staining for hNIS confirmed expression in s.c. and peritoneal tumors following virus treatment. Compared to the controls, CF33-hNIS-antiPDL1-treated mice showed significantly decreased s.c. and peritoneal tumor burden and improved survival (p < 0.05). Notably, 2 of 8 mice showed complete regression of disease. PET/CT avidity for 124I uptake in s.c. and peritoneal tumors was visible starting at day 7 following the first i.t. dose of CF33-hNIS-antiPDL1. We show that CF33-hNIS-antiPDL1 can help detect and kill both s.c. and peritoneal tumors following s.c. i.t. treatment.

Peritoneal Metastasis: Current Status and Treatment Options.

Simple SummarySurgical and locoregional treatments of peritoneal metastasis, e.g., from colorectal cancer, has gained increasing acceptance after the publication of excellent patient outcomes from many groups around the world. Apart from systemic chemotherapy and surgical removal of the tumor, locoregional therapies such as HIPEC or PIPAC may improve tumor control. Understanding the molecular characteristics of peritoneal metastasis is crucial to evolve future therapeutic strategies for peritoneal metastasis. This includes the genetic background of PM, which is often different from other sites of metastasis, and promotes peritoneal dissemination and the growth of tumor cells. Growing knowledge and insight into the physiology of the peritoneal tumor microenvironment and the specific role of the immune system in this compartment may provide a critical step to move locoregional therapy to the next level. This review summarizes the current knowledge and highlights the molecular characteristics of peritoneal metastasis.Peritoneal metastasis (PM) originating from gastrointestinal cancer was considered a terminal disease until recently. The advent of better systemic treatment, a better understanding of prognostic factors, and finally, the advent of novel loco-regional therapies, has opened the door for the multimodal treatment of PM. These strategies, including radical surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) showed surprisingly good results, leading to the prolonged survival of patients with peritoneal metastasis. This has triggered a significant body of research, leading to the molecular characterization of PM, which may further help in the development of novel treatments. This review summarizes current evidence on peritoneal metastasis and explores potential novel mechanisms and therapeutic approaches to treat patients with peritoneal metastasis.

Targeting AURKA in treatment of peritoneal tumor dissemination in gastrointestinal cancer

Intraperitoneal (i.p.) tumor dissemination and the consequent malignant ascites remain unpredictable and incurable in patients with gastrointestinal (GI) cancer, and practical advances in diagnosis and treatment are urgently needed in the clinical settings. Here, we explored tumor biological and immunological mechanisms underlying the i.p. tumor progression for establishing more effective treatments.We established mouse tumor ascites models that murine and human colorectal cancer cells were both i.p. and subcutaneously (s.c.) implanted in mice, and analyzed peritoneal exudate cells (PECs) obtained from the mice. We then evaluated anti-tumor efficacy of agents targeting the identified molecular mechanisms using the ascites models. Furthermore, we validated the clinical relevancy of the findings using peritoneal lavage fluids obtained from gastric cancer patients.I.p. tumor cells were giant with large nuclei, and highly express AURKA, but less phosphorylated TP53, as compared to s.c. tumor cells, suggesting polyploidy-like cells. The i.p. tumors impaired phagocytic activity and the consequent T-cell stimulatory activity of CD11b+Gr1+PD1+ myeloid cells by GDF15 that is regulated by AURKA, leading to treatment resistance. Blocking AURKA with MLN8237 or siRNAs, however, abrogated the adverse events, and induced potent anti-tumor immunity in the ascites models. This treatment synergized with anti-PD1 therapy. The CD11b+PD1+ TAMs are also markedly expanded in the PECs of gastric cancer patients.These suggest AURKA is a determinant of treatment resistance of the i.p. tumors. Targeting the AURKA-GDF15 axis could be a promising strategy for improving clinical outcome in the treatment of GI cancer.

Primary and metastatic peritoneal surface malignancies.

Peritoneal surface malignancies comprise a heterogeneous group of primary tumours, including peritoneal mesothelioma, and peritoneal metastases of other tumours, including ovarian, gastric, colorectal, appendicular or pancreatic cancers. The pathophysiology of peritoneal malignancy is complex and not fully understood. The two main hypotheses are the transformation of mesothelial cells (peritoneal primary tumour) and shedding of cells from a primary tumour with implantation of cells in the peritoneal cavity (peritoneal metastasis). Diagnosis is challenging and often requires modern imaging and interventional techniques, including surgical exploration. In the past decade, new treatments and multimodal strategies helped to improve patient survival and quality of life and the premise that peritoneal malignancies are fatal diseases has been dismissed as management strategies, including complete cytoreductive surgery embedded in perioperative systemic chemotherapy, can provide cure in selected patients. Furthermore, intraperitoneal chemotherapy has become an important part of combination treatments. Improving locoregional treatment delivery to enhance penetration to tumour nodules and reduce systemic uptake is one of the most active research areas. The current main challenges involve not only offering the best treatment option and developing intraperitoneal therapies that are equivalent to current systemic therapies but also defining the optimal treatment sequence according to primary tumour, disease extent and patient preferences. New imaging modalities, less invasive surgery, nanomedicines and targeted therapies are the basis for a new era of intraperitoneal therapy and are beginning to show encouraging outcomes.

Retroperitoneal leiomyosarcoma in a female patient with a germline splicing variant RAD51D c.904-2A\u2009>\u2009T: a case report

BackgroundRAD51D (RAD51 paralog D) is an intermediate cancer susceptibility gene for primary ovarian cancer, including fallopian tube and peritoneal carcinomas and breast cancer. Although gynecological non-epithelial tumors such as uterine sarcomas are associated with genomic instability, including BRCA impairment, there is no clear evidence of the relationship between RAD51D variants and the risk of sarcoma development.Case presentationA Japanese woman in her 50s underwent multiple surgical resections and several regimens of chemotherapy for tumors that originated in the retroperitoneum and recurred in the peritoneum over a clinical course of approximately 4 years. The peritoneal tumor was histologically diagnosed as a leiomyosarcoma and was genetically identified to show a splice variant of RAD51D c.904-2A > T [NM_002878] through tumor profiling performed as a part of cancer precision medicine. The confirmatory genetic test performed after genetic counseling revealed that the RAD51D splicing variant detected in her tumor was of germline origin. In silico analyses supported the possible pathogenicity of the detected splice variant of RAD51D with a predicted attenuation in mRNA transcription and truncated protein production due to frameshifting, which was attributed to a single-nucleotide alteration in the splicing acceptor site at the 3′-end of intron 9 of RAD51D. Considering her unfavorable clinical outcome, which showed a highly aggressive phenotype of leiomyosarcoma with altered RAD51D, this case provided novel evidence for the relationship of a RAD51D splicing variant with malignant tumor development or progression. We report the findings of this rare case with possible involvement of the germline variant of RAD51D c.904-2A > T as a potential predisposing factor for malignant tumors, including leiomyosarcoma.ConclusionsWe present the findings of a case of leiomyosarcoma in the peritoneum of a female patient with a novel germline splicing variant of RAD51D as potential evidence for the pathogenicity of the variant and its involvement in the risk of sarcoma etiology and/or development. To the best of our knowledge, this is the first case report describing a leiomyosarcoma carrying a germline RAD51D splicing variant and elucidating its pathogenicity on the basis of computational prediction of the impairment of normal transcription and the presumed loss of functional protein production.

P093 RESULTS OF CYTOREDUCTION SURGERY AND HYPERTHERMIC INTRAPERITONEAL CHEMOTHERAPY (HIPEC) WITH SIMULTANEOUS COMPLEX RECONSTRUCTION OF THE ABDOMINAL WALL

Abstract Aim “Cytoreductive surgery (CRS) together with the application of hyperthermic intraperitoneal chemotherapy (HIPEC) has proven to be a feasible and effective method in the management of selected patients with peritoneal metastases and/or primary peritoneal tumors. Infiltration of the abdominal wall is a frequent finding in these patients, which often leads to extensive resections and complex parietal reconstructions in the same surgical act. This may be associated with wound complications and the consequent delay in postoperative therapy of the patient. For this reason, an exquisite management of the abdominal wall is required. Our goal is to evaluate the technique and results of two clinical cases that required simultaneous complex reconstructions.” Material and Methods “Review patients undergoing CRS and HIPEC and simultaneous complex abdominal wall reconstruction between 2015 and 2020. Analysis of oncological history, description of the defect resulting from cytoreduction and the reconstruction technique used, postoperative course and medium-term results.” Results “Different techniques were used to reconstruct the abdominal wall according the caracteristics of the defect after cytoreduction. The simultaneous performance of reconstruction techniques did not increase the hospital stay nor the rate of complications of the surgical wound. Systemic chemotherapy was continued without delay and we have no evidence of incisional hernias in the medium term.” Conclusions “In our experience, the use of abdominal wall reconstruction techniques in the same surgical time after performing CRS and HIPEC is safe and with good results in the medium term.”

Peritoneal disease: key imaging findings that help in the differential diagnosis.

The peritoneum is a unique serosal membrane, which can be the site of primary tumors and, more commonly, secondary pathologic processes. Peritoneal carcinomatosis is the most common malignant condition to affect the peritoneal cavity, and the radiologist plays an important role in making the diagnosis and assessing the extent of disease, especially in sites that may hinder surgery. In this review, we address the role of the radiologist in the setting of peritoneal pathology, focusing on peritoneal carcinomatosis as this is the predominant malignant process, followed by revising typical imaging findings that can guide the differential diagnosis.We review the most frequent primary and secondary peritoneal tumor and tumor-like lesions, proposing a systemic approach based on clinical history and morphological appearance, namely distinguishing predominantly cystic from solid lesions, both solitary and multiple.

Anti-Tumor Activity of Expanded PBMC-Derived NK Cells by Feeder-Free Protocol in Ovarian Cancer.

Simple SummaryNatural killer (NK) cell-based cancer therapies have substantially reshaped modern strategies for clinical cancer treatment and have improved outcomes for countless patients, notably in hematologic malignancies. Unfortunately, its efficacy is limited against solid tumors due to poor infiltration and persistence in the tumor microenvironment. In this study, we show that peripheral blood mononuclear cell-derived NK cell cytotoxicity and persistence can be greatly enhanced to provide highly potent and durable anti-tumor activity through expansion in a feeder cell free-expansion system. Importantly, we show expanded-NK efficacy against three distinct forms of ovarian cancer in mouse models (i.e., solid tumors, abdominal metastatic tumors, and ascites).Natural killer (NK) cells have shown great therapeutic potential against a wide range of cancers due to their pan-specific target recognition. Numerous reports indicate that NK cell immunotherapy is an effective therapeutic approach for treating hematological malignancies, but shows limited effects against solid tumors. In this study, several models of ovarian cancer (OC) were used to test the anti-cancer effects of NK cells derived from human peripheral blood mononuclear cells and expanded using a feeder cell-free expansion system (eNKs). The results show that eNKs exhibit potent inhibitory activity on tumor growth in different ovarian cancer xenograft mice (i.e., solid tumors, abdominal metastatic tumors, and ascites), importantly, in a dose-dependent manner. Moreover, adoptive transfer of eNKs resulted in significant reduction in ascites formation in OC peritoneal tumor models, and especially in reducing intraperitoneal ascites. We found that eNKs could migrate to the tumor site, retain their activity, and proliferate to maintain high cell counts in cutaneous xenograft mice. In addition, when increased the infusion with a high dose of 12 × 107 cells/mouse, Graft-versus-host disease could be induced by eNK. These data show that eNK cell immunotherapy could be a promising treatment strategy for ovarian cancers, including solid tumors and ascites.

Expression of CIB1 correlates with colorectal liver metastases but not with peritoneal carcinomatosis

BackgroundMolecular differences in colorectal cancer (CRC) are associated with the metastatic route. Patient survival is mainly driven by metastatic spread thus it is imperative to understand its key drivers to develop biomarkers for risk stratification, follow-up protocols and personalized therapy. Thus, this study aimed to identify genes associated with the metastatic route in CRC.Material and methodsCRC patients resected at our clinic from 2005 to 2014 and with a minimum 5-year follow-up were included in this analysis and grouped into CRC with hepatic (HEP), peritoneal (PER) or without distant metastases (M0), and HEP/PER. Firstly, tumor RNA of 6 patients each was isolated by microdissection from formalin-fixed paraffin-embedded specimens and analyzed by a NanoString analysis. Subsequently, these results were validated with immunohistochemistry and correlated to clinicopathological parameters in a larger collective of CRC patients (HEP n = 51, PER n = 44, M0 n = 47, HEP/PER n = 28).ResultsCompared to M0, HEP tumors showed 20 differentially expressed genes associated with epithelial-mesenchymal transition (EMT) and angiogenesis. Compared to M0, PER tumors had 18 differentially expressed genes. The finding of different gene signatures was supported by the multidimensional principal component clustering analysis. Tumor perforation did not influence the metastatic route. CIB1 was homogenously and significantly overexpressed in HEP compared to M0 (p < 0.001), but not in PER. Furthermore, immunohistochemical validation demonstrated that the mean CIB1 expression in HEP was 80% higher than in M0 (p < 0.001).ConclusionGene expression analysis revealed that CIB1 is significantly overexpressed in CRC leading to liver metastases compared to M0 and PER. Thus, the present results suggest that CIB1 may play a crucial role for hematogenous spread to the liver but not for peritoneal carcinomatosis. Consequently, CIB1 seems to be a promising prognostic marker and a potential tool for future targeted therapies as well as early diagnostics and follow-up.

Host Mesothelin Expression Increases Ovarian Cancer Metastasis in the Peritoneal Microenvironment.

Mesothelin (MSLN), a glycoprotein normally expressed by mesothelial cells, is overexpressed in ovarian cancer (OvCa) suggesting a role in tumor progression, although the biological function is not fully understood. OvCa has a high mortality rate due to diagnosis at advanced stage disease with intraperitoneal metastasis. Tumor cells detach from the primary tumor as single cells or multicellular aggregates (MCAs) and attach to the mesothelium of organs within the peritoneal cavity producing widely disseminated secondary lesions. To investigate the role of host MSLN in the peritoneal cavity we used a mouse model with a null mutation in the MSLN gene (MSLNKO). The deletion of host MSLN expression modified the peritoneal ultrastructure resulting in abnormal mesothelial cell surface architecture and altered omental collagen fibril organization. Co-culture of murine OvCa cells with primary mesothelial cells regardless of MSLN expression formed compact MCAs. However, co-culture with MSLNKO mesothelial cells resulted in smaller MCAs. An allograft tumor study, using wild-type mice (MSLNWT) or MSLNKO mice injected intraperitoneally with murine OvCa cells demonstrated a significant decrease in peritoneal metastatic tumor burden in MSLNKO mice compared to MSLNWT mice. Together, these data support a role for host MSLN in the progression of OvCa metastasis.

EP.TH.299Is peritoneal lavage with water the optimal washout as a preventative method for peritoneal disease following colorectal cancer resection? A systematic review

Abstract Aim To study available data on the advantages of peritoneal lavage with distilled water following colorectal cancer resection in improving overall patient outcomes Methods PubMed, Google Scholar, and Cochrane databases were searched until October 2020. References from relevant articles were reviewed to widen the search. Results Overall, 3 experimental studies were identified. Water was found to be superior to other peritoneal lavage solutions in inducing tumorigenic cell lysis in vitro. Mice who underwent peritoneal lavage with water survived longer and had a significantly reduced peritoneal tumour burden compared to mice who did not undergo lavage or those treated with saline lavage solution. Peritoneal secretions were found to contaminate water lavage and reduce its cell-lytic effect. Nonetheless, complete cell lysis was achieved, in vivo, by prolonging the time of cell exposure to contaminated lavage solution by 20 min. Conclusion Single peritoneal lavage with water is probably safe and may have a positive influence on patient outcomes. Further evidence is required to regard sequential peritoneal lavages with water as beneficial and safe in humans.

Scary Disseminated Peritoneal Parasite Tumors: A Rare Complication after Previous Laparoscopic Myomectomy

<h3>Study Objective</h3> To demonstrate a rare case with complications originated from previous uncontained power morcellation for laparoscopic myomectomy specimen. <h3>Design</h3> Video demonstration of a rare case. <h3>Setting</h3> A local MIS (minimally invasive surgery) center. <h3>Patients or Participants</h3> <b>S</b>ingle patient. <h3>Interventions</h3> Laparoscopic surgery. <h3>Measurements and Main Results</h3> This virgin patient, receiving laparoscopic myomectomy 9 years ago at other hospital, received 2^nd laparoscopic surgery for recurrent symptomatic uterine myomas 5 years ago, when she was 40-year-old of age. Numerous intraperitoneal parasite tumors were noted. Part of the tumor was sent for frozen section, and the result was "spindle cell tumor". These tumors were debulked as possible. Anterior and posterior uterine mass were also removed after careful adhesiolysis. At this time, all the specimens were removed in the retrieval bag. The pathology of the "parasite tumor" was not leiomyoma but turned out to be adenomyosis and adenomatoid tumor. Adjuvant hormone suppression was prescribed, but later was stopped by patient herself due to the untolerable side effect. Recurrent intraperitoneal adenomyomatosis was noted soon after, gradually enlarged, and at last caused serious compression symptoms. She received 3^rd laparoscopic surgery last year (44-year-old of age). Severe intraperitoneal adhesion, with multiple peritoneal tumor seeding (including Morrison pouch, paracolic gutter, mesentery, pararectal area, and previous laparoscopic trocar site), were noted. TLH + BSO, as well as parasite tumor resection/debulking was performed as the final definite surgical treatment. The patient recovered soon after the surgery and lived well now. In this short video, we will only demonstrate the terrible condition of intraperitoneal adenomyomatosis during 2nd debulking surgery. <h3>Conclusion</h3> Intraperitoneal leiomyomatosis or adenomyomatosis is a rare but serious complication following laparoscopic myomectomy procedure. Castration (BSO) may be the final solution to prevent recurrent parasite tumor seeding and growing. From this patient's history, we again learned the importance of contained morcellation during specimen retrieval in laparoscopic myomectomy.