Perfusion Strategies for Cytoreductive Surgery With Heated Intraperitoneal Chemotherapy for Malignant Peritoneal Mesothelioma.

Cytoreductive surgery (CRS) with heated intraoperative intraperitoneal chemotherapy (HIPEC) has been shown to improve survival for patients with malignant peritoneal mesothelioma (MPM). Presently, there is no standardized HIPEC protocol with respect to chemotherapeutic agent, dose, administration temperature, or duration and limited literature comparing outcomes in different regimens. In this study, we analyze common practices and outcomes of published HIPEC regimens to gain insight into current practice to inform future directions of study. We conducted a literature search for investigational studies of CRS and HIPEC for MPM treatment in adults and identified 35 such articles. These studies were analyzed for institution type and location, drug regimens, perfusion temperatures and time, and study outcomes including median survival, complication rates, and perioperative mortality rates. On review, there is significant heterogeneity in HIPEC regimens and outcome reporting metrics, suggesting a need for multi-institutional standardized study protocols to better determine the safest and most efficacious treatment regimen.

Rare confounder: benign multicystic peritoneal mesothelioma in a patient with mucinous colon adenocarcinoma.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, in which patients have multiple cystic lesions of the peritoneum. BMPM can mimic mucinous carcinomatosis and can thus create a diagnostic dilemma. We present the case of a 76-year-old woman who was referred for management of ascending colon adenocarcinoma and was noted to have several nonspecific cystic lesions in the abdomen and pelvis on preoperative computed tomography and diagnostic laparoscopy. Frozen section analysis suggested the lesions contained 'mucin'. Due to concern for metastases, right colectomy was aborted. Final histologic analysis of the laparoscopic biopsies revealed mesothelial cysts, consistent with BMPM, unrelated to her colon adenocarcinoma. Laparoscopic right colectomy was performed 2 weeks later. BMPM can create diagnostic and therapeutic uncertainty in patients with known visceral malignancies when discovered incidentally. Frozen section analysis may not be accurate in differentiating the two, and final histologic confirmation should be sought prior to definitive treatment.

Effect of postoperative normothermic intraperitoneal chemotherapy on the prognosis of MPM patients receiving CRS+HIPEC: A single-center case-control study.

BACKGROUND: The comprehensive treatment strategy, mainly cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), combined with systemic and intraperitoneal chemotherapy, is the standard treatment for malignant peritoneal mesothelioma (MPM), which can significantly prolong the survival of patients. The aim of this study is to investigate the clinical significance of postoperative normothermic intraperitoneal chemotherapy (NIPEC) in MPM patients. METHODS: Data of 152 MPM patients who underwent CRS + HIPEC and postoperative intravenous chemotherapy were retrospectively analyzed. Patients were divided into the Non-NIPEC group and the NIPEC group according to whether they received NIPEC after surgery. The baseline characteristics of the two groups were compared, and the survival outcome was analyzed in subgroups according to completeness of cytoreduction (CC) score. Multivariate survival analysis was used to determine the independent prognostic factors. RESULTS: In CC 0-1 and CC 2-3 subgroups, there was no significant difference in baseline characteristics between Non-NIPEC and NIPEC groups. Survival analysis showed that for CC 0-1 patients, there was no significant difference in overall survival (OS) between Non-NIPEC and NIPEC groups (P = 0.503). However, for CC 2-3 patients, the median OS of the NIPEC group was significantly longer than that of the Non-NIPEC group (24.5 vs. 10.3 months, P = 0.005). Pathological type, preoperative thrombosis and postoperative NIPEC (HR = 0.423, 95%CI: 0.228-0.786, P = 0.006) were independent prognostic factors for CC 2-3 patients. CONCLUSIONS: For MPM patients receiving CRS + HIPEC, postoperative intraperitoneal combined with intravenous chemotherapy may improve the survival of CC 2-3 patients, but CC 0-1 patients do not seem to derive the same benefit.

Survival prediction in peritoneal mesothelioma: a nomogram based on SEER data and a Chinese cohort.

Objective: This study aimed to develop nomogram predicting overall survival (OS) of patients with peritoneal mesothelioma (PeM) using data from Surveillance, Epidemiology, and End Results (SEER) database and a Chinese institution. Methods: 1,177 PeM patients from the SEER database were randomized into training and internal validation cohorts at a 7:3 ratio. An external validation cohort consisting of 109 patients was enrolled from a Chinese institution. Nomogram was constructed based on variables identified through multivariate Cox regression analysis and evaluated by consistency indices (C-index), calibration plots, and receiver operating characteristic (ROC) curves. Patients were stratified into different risk categories, and Kaplan-Meier survival analysis was used to assess OS differences among these groups. Results: The nomogram, incorporating age, gender, histological type, T stage, M stage, and surgical status, demonstrated strong predictive capability with C-index values of 0.669 for the training cohort, 0.668 for the internal validation cohort, and 0.646 for the external validation cohort. The nomogram effectively stratified patients into high-risk and low-risk groups, with the high-risk group exhibiting significantly poorer OS (P < 0.05). Multivariate analysis confirmed gender, age, surgical intervention, and M stage as independent prognostic factors (P < 0.05). Specifically, male gender, older age, and unspecified M stage were linked to worse outcomes, while surgical intervention was associated with improved survival. Conclusion: The nomogram provide a reliable tool for predicting the survival in PeM patients, facilitating more informed treatment decisions. Key independent prognostic factors include gender, age, surgical intervention, and M stage.

Challenging the Norm: Occurrence of Synchronous Pleural and Peritoneal Mesothelioma in a Female Patient.

Here, we present a unique case involving a female patient in her 40s with synchronous malignant pleural and peritoneal mesothelioma, despite lacking a history of asbestos exposure. The patient's initial symptoms included dyspnoea, chest pain, cough, fever, appetite loss, and weight loss over a month. Clinical evaluation led to the identification of right-sided pleural effusion, prompting consideration of differential diagnoses, such as tubercular or malignant pleural effusion. A thoracoscopy-guided biopsy, followed by histopathological examination and immunohistochemical staining, confirmed the diagnosis of mesothelioma. Chemotherapy was initiated as part of the treatment plan. The prognosis for this condition is generally bad; however, unusual cases of extended survival have been documented. The complexities of our case underscore the critical necessity for a thorough and aggressive evaluation of pleural effusion cases to unveil rare underlying causes, such as mesothelioma.

Case report: ATM A1159T mutation in malignant peritoneal mesothelioma may be associated with tumor recurrence.

Malignant peritoneal mesothelioma is an exceedingly rare malignant tumor. Herein, we present a case of malignant peritoneal mesothelioma in a 59-year-old Chinese female patient who was stable after treatment for multiple relapses. Imaging revealed massive ascites and an irregular thickening of the peritoneal mesangium. Laparoscopic biopsy revealed heterogeneous cell nests in the parietal peritoneal fibrous tissue, which were confirmed by immunohistochemical staining for Calretinin, WT-1, and D2-40. In terms of genetic screening, BAP1, CSF1R, and other key driver gene variants closely related to malignant peritoneal mesothelioma have been explored in tumor tissues. Notably, CARD11 driver mutation was first found in all malignant peritoneal mesothelioma patients, and ATM A1159T gene mutation found in recurrent focal tissue may be associated with recurrent tumor recurrence.

Major response of a peritoneal mesothelioma to nivolumab and ipilimumab: a case report, molecular analysis and review of literature.

Malignant peritoneal mesothelioma (MPM) is a rare tumor associated with a poor prognosis and a lack of consensus regarding treatment strategies. While the Checkmate 743 trial demonstrated the superiority of first-line nivolumab and ipilimumab over chemotherapy in malignant pleural mesothelioma (MPlM), few studies have assessed the effectiveness of immunotherapy against MPM, due to its rarity. Here, we report a major and sustained 12-month response in a 74-year-old female patient who received the anti-PD-1 nivolumab and the anti-CTLA4 ipilimumab as first-line therapy for diffuse MPM. PD-L1 was expressed and BAP1 expression was lost, as shown by immunohistochemistry, however the BAP1 gene was not mutated. Our findings suggest a role for ICI in non-resectable diffuse MPM exhibiting PD-L1 overexpression and loss of BAP1 expression, and instill new hope in their treatment. To our knowledge, this is the second reported case of dual immunotherapy used as first-line in MPM with a major clinical response. To investigate the clinical outcome, we conducted additional molecular analyses of the MPM tumor and we reviewed the literature on immunotherapy in MPM to discuss the role of PD-L1 and BAP1.

Development in the Study of Natural Killer Cells for Malignant Peritoneal Mesothelioma Treatment.

Malignant peritoneal mesothelioma (MPeM) is a rare primary malignant tumor originating from peritoneal mesothelial cells. Insufficient specificity of the symptoms and their frequent reappearance following surgery make it challenging to diagnose, creating a need for more efficient treatment options. Natural killer cells (NK cells) are part of the innate immune system and are classified as lymphoid cells. Under the regulation of activating and inhibiting receptors, NK cells secrete various cytokines to exert cytotoxic effects and participate in antiforeign body, antiviral, and antitumor activities. This review provides a comprehensive summary of the specific alterations observed in NK cells following MPeM treatment, including changes in cell number, subpopulation distribution, active receptors, and cytotoxicity. In addition, we summarize the impact of various therapeutic interventions, such as chemotherapy, immunotherapy, and targeted therapy, on NK cell function post-MPeM treatment.

Drug sensitivity tumor cell clusters in malignant peritoneal mesothelioma.

BACKGROUND: To explore the most effective adjuvant chemotherapy regimen for malignant peritoneal mesothelioma (MPM) through patient derived tumor-like cell clusters (PTC) drug sensitivity test. METHODS: PTC were cultured in vitro with intraoperative specimens, and drug sensitivity test was performed to calculate the most effective chemotherapy regimen for MPM. The patients were divided into conventional and individualized chemotherapy group according to whether they received PTC drug testing. Univariate and multivariate analyses were conducted to identify independent prognostic factors. RESULTS: Among 186 MPM patients included, 63 underwent PTC culture and drug sensitivity test. The results showed that the most effective chemotherapy regimen was oxaliplatin + gemcitabine. After propensity score matching, a total of 64 patients were enrolled in the following study, including 32 patients receiving individualized chemotherapy guided by PTC drug results as group 1 and 32 patients receiving conventional chemotherapy as group 2. Survival analysis showed that the median OS of group 1 was not reached, significantly longer than that of group 2 (23.5 months) (p < 0.05). CONCLUSIONS: Compared with conventional chemotherapy, individualized chemotherapy guided by PTC drug sensitivity tests can prolong patient survival, and oxaliplatin + gemcitabine + apatinib could be the optimal adjuvant treatment regimen for MPM.

Research progress of malignant peritoneal mesothelioma with paraneoplastic syndrome: A review.

Malignant peritoneal mesothelioma (MPM) is a rare and invasive tumor, and some patients will develop paraneoplastic syndrome (PS) during the course of the disease. This review summarizes PS associated with MPM, focusing on the clinical characteristics and treatment progress in hematological, endocrine, rheumatic, neurological, urinary, and other systems to decrease missed diagnosis and misdiagnosis, help early diagnosis and prompt treatment, and provide guidance for the clinical decision-making of this kind of patients.

Primary Peritoneal Mesothelioma Affecting the Greater Omentum That Mimicked an Omental Infarction: A Case Report.

Introduction: Malignant peritoneal mesothelioma (MPM) is a rare cancer that is associated with asbestos exposure. The diagnosis can be difficult given the nonspecific nature of presenting symptoms and the presence of concomitant confounding findings. Case Presentation: We report a 71-year-old male who presented with right lower quadrant pain and new-onset ascites. CT imaging of the abdomen/pelvis demonstrated omental stranding concerning for a possible omental infarction. Subsequent imaging showed persistent omental edema but no identifiable soft tissue mass. A biopsy of the omentum showed atypical mesothelial proliferation, but pathology was unable to determine if proliferation was a neoplastic versus reactive process. Surgical oncology performed a diagnostic laparoscopy that showed peritoneal studding of the omentum. Subsequent immunohistochemical staining of the omentum demonstrated preservation of BAP1 expression and loss of MTAP expression, consistent with peritoneal mesothelioma. Conclusion: MPM is a rare and aggressive cancer with an overall poor prognosis. The diagnosis of MPM can be difficult based on the nonspecific clinical presentation, insufficient imaging and laboratory testing, and the presence of concomitant confounding findings, such as with this patient and his admitting diagnosis of omental infarction. This case demonstrates the importance of developing a broad differential while maintaining an awareness of heuristics that can influence clinical decision-making.

Dual Malignancies Discovered: A Rare Case of Malignant Peritoneal Epithelioid Mesothelioma and Lung Adenocarcinoma.

Clinicians diagnosing malignant peritoneal epithelioid mesothelioma (MPM or MPeM) have historically had challenges due to the low incidence of the disease, as well as the often vague symptomatology that patients present with. Newer advances in technology, specifically in immunocytochemistry, have provided a clearer path to diagnosis. Additionally, malignant mesotheliomas must be differentiated from carcinomas. This is done via histology, immunocytochemistry, as well as a careful incorporation of the patient's clinical history. In this case, we present an asymptomatic 73-year-old non-smoker female with no past medical history of asbestos exposure. She was diagnosed with MPM following a routine abdominal hernia repair. Subsequent workup revealed a lung infiltrate that was successfully biopsied and resected, evidently found to be adenocarcinoma. A careful review of the resulting pathology, as well as the interpretation of immunocytochemistry, supported the notion that the patient had two independent malignant processes occurring at once. This case underscores the rarity of two similar, yet distinct cancers, as well as epidemiology, symptomatology, histology, immunocytochemistry, and prognosis.

Imaging in pleural Mesothelioma: A review of the 16th International Conference of the International Mesothelioma Interest Group.

Imaging continues to gain a greater role in the assessment and clinical management of patients with mesothelioma. This communication summarizes the oral presentations from the imaging session at the 2023 International Conference of the International Mesothelioma Interest Group (iMig), which was held in Lille, France from June 26 to 28, 2023. Topics at this session included an overview of best practices for clinical imaging of mesothelioma as reported by an iMig consensus panel, emerging imaging techniques for surgical planning, radiologic assessment of malignant pleural effusion, a radiomics-based transfer learning model to predict patient response to treatment, automated assessment of early contrast enhancement, and tumor thickness for response assessment in peritoneal mesothelioma.

Intra-Operative Diagnosis of Benign Multicystic Peritoneal Mesothelioma: A Case Report of Rare Entity and Lessons Learned.

Benign multicystic peritoneal mesothelioma (BMPM), also known as multicystic peritoneal mesothelioma (MCPM), is a rare cystic neoplasm arising from the mesothelium lining of the abdominal and pelvic peritoneum. This entity has been disproportionately described in women of reproductive age. Both the etiology and pathogenesis of the condition are not well understood. Preoperative diagnosis is challenging as differentials are varied and include endometriosis, lymphangioma, pseudomyxoma peritonei, cystic adenomatoid tumor, and malignant peritoneal mesothelioma. Management options include cytoreductive surgery (CRS) with or without heated intraperitoneal chemotherapy (HIPEC). In this case report, we highlight the complexity of preoperative diagnosis, presentation, workup, treatment, and management of BMPM. We report the case of a female patient presenting with abdominal pain and imagining consistent with cystic intra-abdominal lesions. After an inconclusive percutaneous biopsy and a multi-disciplinary tumor board discussion, the patient was offered CRS with HIPEC. Intra-operative frozen section indicated benign epithelial lined cysts. CRS and HIPEC were performed. After a second opinion, the lesions were confirmed by pathology and immunohistochemistry to be BMPM. In this report, we discuss the gold standard of care for patients with BMPM to improve the disease control rate. This pathway is proposed in our study, and, thus, we conclude that BMPM should be considered in the differential diagnosis of patients presenting with symptomatic multiple intraperitoneal cystic lesions.

Benign multicystic peritoneal mesothelioma in a sexagenerian man: an uncommon case presentation.

BACKGROUND: Multicystic mesothelial cyst is a rare, and usually benign, tumor which is rarely diagnosed preoperatively due to the poor specificity of its symptomatology. METHODS: We report the case of a 63-year-old man with multiple comorbidities (e.g. cryptogenic cirrhosis, chronic heart failure) and a history of surgical resection of a giant abdominal cyst, who complained of recurrent intermittent abdominal pain and vomiting that appeared several weeks before. Abdominal computed tomodensitometry (CT) revealed multiple diffusely localized cysts in the abdominal cavity, ranging from 30 mm to 210 mm. RESULTS: The patient underwent surgical resection of twelve intra-abdominal cysts, identified at final pathology as benign mesothelial cysts, which were probably a recurrence following the previous surgery for a single intra-abdominal cyst. Three months later, the patient recurred with development of two new intraperitoneal cysts, with an increasing volume on CT at last follow-up (18 months). Surveillance was recommended given the patient's comorbidities and the absence of symptoms. CONCLUSIONS: Surgical resection is the treatment of choice for multicystic peritoneal mesothelioma, a rare disease that should be considered more as a borderline tumor than a benign tumor, given the high risk of recurrence and possible malignant transformation.

Malignant peritoneal mesothelioma presenting with bilateral hydronephrosis and renal insufficiency: a case report and literature review.

Introduction: Malignant peritoneal mesothelioma (MPM) is an extremely rare tumor with nonspecific clinical manifestations, making diagnosis challenging. Case presentation: Herein, we report a case of MPM with occult onset presenting with bilateral hydronephrosis and renal insufficiency. A 30-year-old man was admitted to the Urology Department because of recurrent bilateral lower back pain. The etiology was unclear after a series of laboratory tests, imaging examinations, bone marrow aspiration, renal puncture biopsy, ascites examination, ureteroscopy, and so on. Finally, MPM was diagnosed by laparoscopic exploration and biopsy. Moreover, during the course of the disease, the patient's bilateral ureters were compressed, and the obstruction could not be relieved after the placement of ordinary ureteral stents. Percutaneous nephrostomy or metal ureteral stenosis was appropriate in managing malignant ureteral obstruction as it could improve renal function. Conclusions: The onset of this case was insidious, and the diagnosis was difficult, with a poor prognosis. To date, only a handful of cases have been reported. We hope this case can provide some enlightenment for our clinical work.

Comprehensive genomic profiling of pediatric peritoneal mesothelioma: case report with a literature review.

Malignant peritoneal mesothelioma is an extremely rare and poorly recognized neoplasm in children. A 5-year-old boy presented with a 1-year history of progressive painless abdominal distension. A CT revealed a 19 × 19 × 11 cm3 cystic mass in the right hemiabdomen, without infiltrating the surrounding structures. The tumor was completely removed by surgery. The microscopic and immunohistochemical analyses confirmed peritoneal mesothelioma. Comprehensive genomic profiling revealed no major driving mutations including BAP1, no fusions, but with amplifications of AURKA, AURKC, HLA-1B, ZNF-217, OR5F1 and MEN1 genes. Imaging follow-up 3 months after surgery revealed metastatic disease. The patient died of pneumonia at another hospital shortly after the last follow-up examination at our institution. Pediatric peritoneal mesothelioma is an extremely rare malignancy with limited targeted options and a poor prognosis. Some of the identified molecular genomic biomarkers require further exploration and validation in this cancer.

Peritoneal inclusion cyst presenting as an umbilical hernia: case report and systematic review of the literature.

Peritoneal inclusion cysts (PICs) are a rare and benign condition of uncertain pathogenesis. The fluid-filled, mesothelial-lined cysts manifest within the abdominopelvic cavity. This case report details an unusual occurrence of a 97 mm PIC- presenting as an umbilical hernia- in a 26-year-old male patient with no prior surgical history. Following pre-operative cross-sectional imaging, this was managed through open excision without complication. A systematic review of the literature highlighted 30 previous cases [26F, 4M] with a mean age of 34 years (std ±15.4) and a median diameter of 93 mm [IQR, 109 mm]. A total of 53% (n = 16) of cases had a history of previous abdominal surgery. Surgical excision is safe and laparoscopic modality should be considered (<1% recurrence). Accepting the limited evidence base, image guided drainage should be avoided (50% recurrence, n = 2).

Single-incision laparoscopic surgery for benign multicystic mesothelioma of the peritoneum in a young man: A case report.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, particularly in men, and the preoperative diagnosis poses a challenge. Here, we present a case involving single-incision laparoscopic surgery (SILS) for BMPM in a 24-year-old man with a pelvic mass and a history of ulcerative colitis. Pelvic imaging revealed multifocal cysts, prompting the performance of SILS. The tumor was successfully resected with no residual lesions, and pathology confirmed the diagnosis of BMPM. This case represents the first documented instance of SILS being employed for BMPM in a man. BMPM, characterized by pelvic multifocal cysts, is a differential diagnosis, and SILS emerges as a viable option for both diagnosis and treatment.