Important Predictive Factors for the Prognosis of Patients With Peritoneal Metastasis of Gastric Cancer.

BACKGROUND: This study investigated predictive factors for patients with peritoneal metastases of gastric cancer (PMGC) who underwent conversion cytoreductive surgery (C-CRS) and hyperthermic intraperitoneal intraoperative chemotherapy (HIPEC) after responding to induction chemotherapy (laparoscopic HIPEC [LHIPEC]) followed by concomitant systemic and intraperitoneal chemotherapy (bidirectional intraperitoneal and systemic chemotherapy [BIC]). METHODS: Diagnostic laparoscopy was performed for 62 patients with PMGC between January 2017 and December 2022. The patients underwent LHIPEC and BIC induction chemotherapy using intraperitoneal docetaxel (30 mg/m2) and cisplatin (30 mg/m2), and intravenous chemotherapy for three cycles. The predictive parameters for progression-free and overall survival were analyzed using Kaplan-Meier and Cox regression analyses. The optimal cutoff values for Ki-67 parameters were assessed using receiver operating characteristic curve analysis. RESULTS: The study retrospectively examined 36 (58 %) of 62 patients who responded to induction therapy and underwent C-CRS or HIPEC. A Ki-67 index lower than 10 (p = 0.000), lymph node involvement (LNI) less than 2 (p = 0.039), and an omental lesion size score lower than 0.5 cm (p = 0.002) were predictive of recurrence-free and overall survival in addition to completeness of cytoreduction and the peritoneal cancer index. Cox regression analysis showed that the independent factors associated with recurrence-free survival were decreased Ki-67 expression (≥10 % vs <10 %) (hazard ratio [HR] 4.7; 95 % confidence interval [CI] 1.6-5.210; p = 0.020) and LNI higher than 2 (HR 1.92; 95% CIS 0.923-4.0; p = 0.023). CONCLUSIONS: Lymph node involvement and decreased Ki-67 expression are independent predictive factors of recurrence-free survival for patients with PMGC after induction chemotherapy.

Peritoneal metastasis of advanced epithelial ovarian carcinoma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: A retrospective international multicentric data analysis.

INTRODUCTION: The purpose of our study was to evaluate outcome data after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal metastasis originating from advanced epithelial ovarian carcinoma (PMOC). PATIENTS AND METHODS: A retrospective international multi-institutional registry was established through collaborative efforts of participating units affiliated with the Peritoneal Surface Oncology Group. RESULTS: One thousand four hundred and ninety-one patients from 11 specialized units underwent CRS and HIPEC that of those 326 (21.9%) upfront surgeries, 504 (33.8%) interval surgery, and 661(44.3%) recurrent cases. Complete Cytoreduction(CC0/1) was achieved in 1213 patients (81.3%). Treatment -related mortality was 0.8%, major operative complications (Grades 3-5) was 25.1%. Factors associated with major operative complications include prior surgical score (PSS for recurrent cases; RC) PSS>2,p = 0.000), PCI(≤15, >15 cut-off level; p ≤ 0.000), completeness of cytoreduction (CC, p=0.000), high CA125 levels (>25 mg/dl), presence of ascites, high CRP (>5 mg/dl) levels and low albumin levels (below to 2.5 mg/dl) (p ≤ 0.05). The median survival was 58 months in upfront surgery(UFS), 60 months in interval surgery(IS), and 42 months in RC. The overall survival for five years was 45% for UFS, 37% for IS, 28% for RC cases. CCscore (p = 0.000), CA125, CRP and albumin levels (p ≤ 0.05) were predictors for progression free survival. PCI(p ≤ 0.000), major postoperative complications (p = 0.004), incomplete CRS(CC2/3)(p < 0.001), prior chemotherapy (hazard ratio [HR], 3-8; p < 0.001) and PSS>2 for RC were independent predictors of poor overall survival. CONCLUSION: The combined treatment strategy for PMOC may be performed safely with acceptable morbidity and mortality in the specialized units.

Determining a minimum data set for reporting clinical and radiologic data for pseudomyxoma peritonei.

Objectives: Pseudomyxoma peritonei (PMP) is a rare cancer currently affecting over 11,736 patients across Europe. Since PMP is so uncommon, collaboration between scientific centers is key to discovering the mechanisms behind the disease, efficient treatments, and targets pointing to a cure. To date, no consensus has been reached on the minimum data that should be collected during PMP research studies. This issue has become more important as biobanking becomes the norm. This paper begins the discussion around a minimum data set that should be collected by researchers through a review of available clinical trial reports in order to facilitate collaborative efforts within the PMP research community. Content: A review of articles from PubMed, CenterWatch, ClinicalTrials.gov and MedRxiv was undertaken, and clinical trials reporting PMP results selected. Summary: There is a core set of data that researchers report, including age and sex, overall survival, peritoneal cancer index (PCI) score, and completeness of cytoreduction, but after this, reports become variable. Outlook: Since PMP is a rare disease, it is important that reports include as large of a number of standardised data points as possible. Our research indicates that there is still much ground to cover before this becomes a reality.

The Role of PPAR-gamma C161T Polymorphism in Colorectal Cancer Susceptibility.

BACKGROUND/AIM: This study aimed to determine the role of the peroxisome proliferator-activated receptor-gamma (PPARg) C161T genotype and allele frequencies in predisposition to colorectal cancer (CRC). PATIENTS AND METHODS: PPARg C161T (His447His; rs3856806) gene polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism analysis in patients with CRC (n=101) and controls (n=238). RESULTS: The T161 allele (CT+TT genotypes) of PPARg C161T polymorphism was associated with CRC development (p<0.001; OR=3.239, 95%CI=1.997-5.252). Subgroup analysis showed that the T161 allele was associated with a 3.056-fold increased risk for colon cancer (CC) (p<0.001; 95%CI=1.709-5.464) and 3.529-fold increased risk for rectal cancer (RC) (p<0.001; 95%C=1.784-6.981). Frequencies of the T161 allele were also higher in total CRC and CC patients with poorly differentiated tumors (p<0.001, c2=30,601, OR=3.109; 95%CI=1.970-4.906 and p<0.001, Fisher exact test, respectively). CONCLUSION: PPARg T161 allele carriers have increased risk for developing CRC.

The Characteristics of 206 Long-Term Survivors with Peritoneal Metastases from Colorectal Cancer Treated with Curative Intent Surgery: A Multi-Center Cohort from PSOGI.

BACKGROUND: We conducted this study to review the patient characteristics associated with long-term survival in patients with peritoneal metastases from colorectal cancer who underwent cytoreductive surgery (CRS). METHODS: We retrospectively investigated patients with peritoneal metastases from CRC treated with curative intent surgery with or without hyperthermic intraperitoneal chemotherapy at 13 institutions worldwide between January 1985 and April 2015 and survived longer than five years after the first CRS for peritoneal metastases. Clinical and oncological features and therapeutic parameters were described and analyzed. RESULTS: Two hundred six long-term survivors were available for study. The median peritoneal cancer index (PCI) of this cohort was 4 (interquartile range (IQR), 2-7), and the median score of the small bowel regions of the PCI (SB-PCI) was 0 (IQR, 0-2). Complete cytoreduction (CC-0) was achieved in 180 (87.4%) patients. Recurrence was observed in 122 (59.2%) patients at a median of 1.8 (IQR, 1.2-2.6) years. CONCLUSIONS: While most long-term survivors showed low PCI/SB-PCI and CCR-0, some had characteristics considered associated with poor prognosis. Curative intent treatments may be considered in well-informed and fit patients showing negative factors affecting survival outcome.

Surgery with hyperthermic intraperitoneal chemotherapy after response to induction chemotherapy in patients with peritoneal metastasis of gastric cancer.

BACKGROUND: Gastric cancer (GC) with peritoneal metastases (PM) has a dismal prognosis and to date only a few management options have been reported. Of those, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) after induction bidirectional intraperitoneal and systemic chemotherapy (BIPSC) appear as a promising treatment option for these patients. Outcome data including safety and efficacy of CRS with radical Gastrectomy and HIPEC after response to combination of laparoscopic HIPEC (LHIPEC) with BIPSC as an induction therapy in patients with PM of GC was evaluated in this retrospective observational study. METHODS: Diagnostic Laparoscopy was performed in 53 patients with PM of GC who admitted to the Center for Treatment of Peritoneal Surface Malignancies, Istanbul, between 2013 and 2016. Peritoneal cancer index (PCI), ascites status and cytology were determined. The patients underwent LHIPEC and then, BIPSC induction chemotherapy using intraperitoneal docetaxel (30 mg/m2) and cisplatin (30 mg/m2) and intravenous Docetaxel/Cisplatin/5-Fluorouracil (DCF) for 3 cycles. In selected patients, CRS with radical gastrectomy and HIPEC were performed after the response to induction therapy. BIPSC was continued for 3 more cycles with a dose reduction in an adjuvant setting. RESULTS: All LHIPEC procedures were uneventful with Grade 1-2 side effects (11/53, 20,8%). As a response to induction chemotherapy PCI was reduced from 19.6±8 (range, 6-39) to 13.6±9.8 (range, 1-39) (P<0.001). Ascites was detected in 55% (29 out of 53) and cytology was positive in 51% (27 out of 53) of the patients before induction chemotherapy. Ascites was completely abolished and all cytology became negative. Then, 34 of 53 (64.15%) patients underwent CRS with radical gastrectomy and HIPEC. CC0/1 resection was achieved in 22 (64.70%) of patients (P<0.05). The median survival time was 18.9±13.4 (95% CI: 15.2-22.6 months. Combined surgery and HIPEC related mortality occurred in 1 out of 34 patients (2.9%) due to developed diffuse intravascular coagulation at postoperative day 2. Grade 2 operative complications included biliary fistula in one, and duodenal stump leakage in two patients (8.7%). All of the fistula closed with conservative management. The median survival time was 18.9±13.4 months and the median progression-free survival time was 15.6±12.9 with 1-, 2-, and 5-year survival rates of 82.4%, 59% and 17.6% in patients with PM of GC. Multivariate analysis identified high peritoneal cancer index (P=0.000) and complete resection (P<0.05) as independent predictors for better progression-free and overall survival. CONCLUSIONS: The best outcomes can be expected with optimal cytoreduction and limited peritoneal dissemination in response to induction chemotherapy. Knowledgeable selection of patients with PM of GC is essential to perform surgery with HIPEC safely with acceptable mortality and morbidity.

Analysis of Treatment Failure after Complete Cytoreductive Surgery for Peritoneal Metastasis from Appendiceal Mucinous Neoplasm at a Japanese High Volume Center for Peritoneal Surface Malignancy.

BACKGROUND AND OBJECTIVES: Treatment failure after complete cytoreduction for appendiceal mucinous carcinoma peritonei (AMCP)has not been fully investigated. The present study was performed to clarify the risk factor for recurrence after complete cytoreduction for AMCP. METHODS: A total of 400 patients with AMCP who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated. RESULTS: Documented recurrence was developed in 135 (33.8%)patients. The 5- and 10-year progression-free survival was 51% and 49%, respectively. By multivariate analysis, histological subtype of peritoneal disease(high-grade AMCP[AMCP-H]and AMCP-H with signet ring cells), serum CA19- 9 level, and PCIB20 were significantly associated with reduced progression-free survival. In contrast, histologic subtype of mucin without epithelial cells(MWEC)showed the lowest risk for recurrence. Eighty-six patients had localized intra-abdominal recurrence, and 42 patients had diffuse peritoneal recurrence. Recurrence was found in the various peritoneal sectors. Eighty-one patients underwent complete cytoreduction for the recurrence, and the overall survival 5-year survival rate after secondary cytoreduction was 49%. CONCLUSIONS: Risk factors for recurrence were histologic subtype, PCI cutoff level, and serum CA19-9 levels. Aggressive second attempt of cytoreduction in patients with localized recurrence improved the survival.

Prognostic Factors of Malignant Peritoneal Mesothelioma Experienced in Japanese Peritoneal Metastasis Center.

BACKGROUND AND OBJECTIVES: The current standard of treatment for malignant peritoneal mesothelioma(MPM)is cytoreductive surgery(CRS)plus perioperative intraperitoneal or systemic chemotherapy(comprehensive treatment), The present study was performed to clarify the prognostic factors of PMP after comprehensive treatment. METHODS: Among 63 patients with MPM, male and female patients were 34 and 29. CRSwas performed in 47 patients and complete cytoreduction(CC-0) was performed in 14(22%)patients. Mean numbers of resected peritoneal sectors and organs were 5.2(1-13), and 2.9(0- 9), respectively. Hyperthermic intraperitoneal chemoperfusion(HIPEC)was performed in 27 patients. Grade 1/2, Grade 3, and Grade 4 complications were experienced in 5, 6, and 3 patients, respectively. One patient died of sepsis, and the mortality rate was 2.3%. Independent prognostic factors for favorable prognosis were performance of HIPEC, peritoneal cancer index (PCI)score C12, no distant metastasis and histologic epithelial type. Relative risk of no HIPEC, PCI score B13, presence of distant metastasis and non epithelial type were 7.69, 22.1, 3.6 and 3.9, respectively. CONCLUSIONS: Risk factors for death after comprehensive treatment were no HIPEC, PCI score B13, and non epithelial type. However, only 11(17%)patients showed PCI score C12. Accordingly, PCI score should be reducedC12 before CRSby neoadjuvant chemotherapy.

Combination Technique Is Superior to Dye Alone in Identification of the Sentinel Lymph Node in Male Breast Cancer.

Sentinel lymph node (SLN) biopsy is the main method in staging the axilla. There are insufficient data available regarding the accuracy of an SLN biopsy in male breast cancer. The aim of this study is to evaluate whether the combination of dye and radiotracer would improve the detection rate of SLNs versus dye alone in male breast cancer patients. From February 2009 to January 2012, our SLN biopsy database was retrospectively reviewed to identify male breast cancer cases. Of the 890 SLN procedures contained in the database, 10 male breast cancer patients were identified. Patient age, body mass index, SLN biopsy technique, SLN identification, number of SLN excised, and pathology reports were reviewed. Mean age was 57.2 (34-85) years with a mean tumor size was 2.2 (1.0-4.0) cm. SLN detection ratios were two in four with blue dye and six in six with the combination technique. Overall, SLNs were identified in 8 of the 10 patients. SLN biopsy is applicable in male breast cancer cases. The addition of a radiotracer to the dye in SLN biopsy increases the detection rate of sentinel nodes in male breast cancer patients.

Photodynamic Detection of Peritoneal Metastases Using 5-Aminolevulinic Acid (ALA).

In the past, peritoneal metastasis (PM) was considered as a terminal stage of cancer. From the early 1990s, however, a new comprehensive treatment consisting of cytoreductive surgery and perioperative chemotherapy has been established to improve long-term survival for selected patients with PM. Among prognostic indicators after the treatment, completeness of cytoreduction is the most independent predictors of survival. However, peritoneal recurrence is a main cause of recurrence, even after complete cytoreduction. As a cause of peritoneal recurrence, small PM may be overlooked at the time of cytoreductive surgery (CRS), therefore, development of a new method to detect small PM is desired. Recently, photodynamic diagnosis (PDD) was developed for detection of PM. The objectives of this review were to evaluate whether PDD using 5-aminolevulinic acid (ALA) could improve detection of small PM.

Comprehensive Treatment Using Cytoreductive Surgery Combined with Perioperative Chemotherapy Improved Outcome of Colorectal Cancer Patients with Metachronous Peritoneal Metastasis.

To analyze the role of cytoreductive surgery(CRS)plus perioperative chemotherapy on the survival of colorectal cancer(CRC)patients with metachronous peritoneal metastasis(PM). A comprehensive treatment consisting of neoadjuvant chemotherapy plus CRS was performed in 291 CRC patients. Among the 291, 142 and 149 patients had synchronous and metachronous PM, respectively. The results showed no survival difference between the 2 groups. Median survival time(MST)of patients with metachronous PM with complete cytoreduction(CCR-0), small bowel(SB)-PCIC2, PCIC14 and differentiated histologic type ranged from 3.1 to 4.1 years. Five-year survival rates of metachronous group of the CCR-0, SB-PCIC2, PCI C14 and differentiated histologic type ranged from 25.8 to 38.9%. However, the 5-year survival rates of the incomplete cytoreduction(CCR-1), SB-PCIB3, PCIB15 and poorly differentiated type were significantly lower than those of the CCR-0, SB-PCIC2, PCIC14 and differentiated histologic type. Postoperative Grade 3, and Grade 4 morbidity were experienced in 11(5.8%)and 16(10.7%)in metachronous group. Mortalities of metachronous group were 1.3%(2/149). The comprehensive treatment can be performed safely and improves the survival of CRC patients with metachronous PM. After NAC, patients with SB-PCIC2, PCIC14 and differentiated type of histology are candidates for CRS, and CCR-0 resection combined with HIPEC is recommended.

Evolution of management in peritoneal surface malignancies.

Management of peritoneal surface malignancies has gradually evolved by the introduction of cytoreductive surgery in combination with intraperitoneal chemotherapy applications. Recently, peritoneal metastases of intraabdominal solid organ tumors and primary peritoneal malignancies such as peritoneal mesothelioma are being treated with this new approach. Selection criteria are important to reduce morbidity and mortality rates of patients who will experience minimal or no benefit from these combined treatment modalities. Management of peritoneal surface malignancies with this current trend is presented in this review.

5-Aminolevulinic Acid Fluorescence in Detection of Peritoneal Metastases.

BACKGROUND: The value of 5-aminolevulinic acid (ALA) in fluorescence detection of peritoneal metastases and the underlying mechanisms were evaluated in patients with peritoneal surface malignancies. MATERIALS AND METHODS: Oral 5-ALA was administered at a concentration of 20 mg /kg body weight with 50 ml of water 2 hours prior to surgery (n=115). The diagnostic value of 5-ALA based fluorescence production was evaluated following white light inspection during prior to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Then, peptide transporter PEPT1 (ALA influx transporter) and ATP-binding cassette transporter ABCG2 (porphyrin efflux transporter) gene expression was determined with quantitative real time (qRT)-PCR and pathological diagnoses confirmed for all tissue samples. RESULTS: The 5-ALA based photodynamic detection rate was 17% for appendiceal mucinous neoplasms, 54% for colorectal cancers, 33% for gastric cancers, 67% for diffuse malign peritoneal mesotheliomas, and 89% for epithelial ovarian cancer of peritoneal metastases. 5-ALA was detected in all cases of peritoneal metastases originating from cholangiocarcinomas whereas it was not able to detect any in granulosa cell and gastrointestinal stromal tumor cases. Furthermore, PEPT1 was overexpressed whereas ABCG2 expression was downregulated in tumors detected with fluorescence. CONCLUSIONS: 5-ALA provided 100% specificity and high sensitivity to detect peritoneal metastases in subgroups of patients with peritoneal surface mailgnancies. ALA influx transporter PEPT1 and porphyrin efflux transporter ABCG2 genes are important in tumor specific 5-ALA induced fluorescence in vivo. Further studies should clarify diagnostic utility of 5-ALA in peritoneal surface malignancies.

Treatment Failure Following Complete Cytoreductive Surgery for Peritoneal Metastasis from Colorectal Cancer.

Treatment failure after complete cytoreduction for peritoneal metastasis(PM)from colorectal cancer(CRC)has not been fully investigated. The present study was performed to clarify the risk factors for recurrence after complete cytoreduction for CRC with PM and the role of repeat surgery for recurrence. MATERIALS AND METHODS: A total of 205 patients with CRC who underwent complete cytoreductive surgery combined with perioperative chemotherapy were investigated. RESULTS: Recurrence occurred in 149(73%)patients. The 5-year overall and progression-free survival rates were 26%and 7%, respectively. By multivariate analysis, positive cytology, serum CEA level higher than normal range, and small bowel peritoneal cancer index B3 were significantly associated with reduced progression-free survival. Blood-borne recurrence was found in 62 (44%)of 149 patients. Repeat surgery was performed in 44(30%), and complete removal was performed in 28(64%) patients. Long-term survival after repeat surgery was experienced in patients with localized peritoneal recurrence and/or liver recurrence. CONCLUSIONS: This study showed that a second attempt at cytoreduction in patients with localized intra-abdominal and liver recurrence is of benefit. Blood-borne recurrence was found in 44% of recurrent patients. The prophylaxis of recurrence should therefore be performed using systemic chemotherapy after CRS plus HIPEC.

Cytoreductive surgery under aminolevulinic acid-mediated photodynamic diagnosis plus hyperthermic intraperitoneal chemotherapy in patients with peritoneal carcinomatosis from ovarian cancer and primary peritoneal carcinoma: results of a phase I trial.

BACKGROUND: We conducted a phase I clinical trial to evaluate the sensitivity, specificity, and safety of cytoreductive surgery (CRS) under aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD) plus hyperthermic intraperitoneal chemotherapy (HIPEC) on 20 patients with peritoneal carcinomatosis (PC) from ovarian cancer and primary peritoneal carcinoma (PPC). PATIENTS AND METHODS: Patients took 5-aminolevulinic acid (5-ALA) at a dose of 20 mg/kg orally with 50 mL of water 2 h before surgery. During surgery, the abdominal cavity was observed under blue light (wavelength of 440 nm) before and after CRS plus HIPEC. Specimens were excised and submitted for pathological examination to evaluate the specificity of ALA-PDD. Postoperative course was closely monitored and detailed information was recorded. RESULTS: CRS under ALA-PDD plus HIPEC was performed 21 times in 20 patients with PC (16 ovarian cancer, 4 PPC) between June 2011 and October 2013. With the exception of 1 (5 %) patient, strong red fluorescence was detected in 19 patients with ovarian cancer, with a sensitivity of 95 %. All specimens from red fluorescent lesions were invaded by cancer cells, with a specificity of 100 %. No severe adverse events occurred during the perioperative period, with the exception of some abnormal laboratory results and mild complications. All patients were alive until the last follow-up. CONCLUSION: ALA-PDD provided a high sensitivity and specificity in detecting peritoneal metastasis in patients with PC from ovarian serous carcinoma and PPC. CRS under ALA-PDD plus HIPEC was a feasible and safe treatment option for patients with PC from ovarian cancer and PPC.

GSTT1 is deregulated in left colon tumors.

Our aim was to determine GSTT1 expression levels in left colon tumors and paired normal tissue in order to identify specific alterations in GSTT1 mRNA levels. Alterations in GSTT1 expression in twenty-four left- sided colon tumors and paired cancer free tissue were determined by qRT-PCR. Significant fold changes were determined with t-test. When compared with cancer free tissue, left colon cancers showed a significant decrease in GSTT1 expression. However, GSTT1 mRNA levels among different grades increased gradually in correlation with tumor grade. Our results suggest that downregulation of GSTT1 in left-sided colon cancers is an early event and is reversed with cancer progression, probably due to cellular defense mechanisms as a response to changes in the microenvironment.

Intraperitoneal chemotherapy and its evolving role in management of gastric cancer with peritoneal metastases.

Advanced gastric cancer (GC) has been recognized as lethal disease when peritoneal metastases (PM) occurred. There is no standard treatment for advanced GC with PM. Until 1980s, the therapeutic arena for these patients had remained stagnant, with no therapeutic approach having shown a survival gain in GC with PM. However, cytoreductive surgery (CRS) with peritonectomy procedures and intraperitoneal chemotherapy (IPC) promising new combined therapeutic approach to achieve disease control for GC with PM. The recent publications changed the GC with PM treatment landscape by providing an evidence that CRS and IPC led to prolongation in overall survival (OS). This review will provide an overview of the evolving role of CRS and IPC in the management of advanced GC with PM in the current era.

Peritoneal cancer treatment.

INTRODUCTION: In the past, peritoneal surface malignancy (PSM) was considered as a final stage of cancer, and patients were offered the best supportive care. Recently, a new therapeutic alternative approach based on the combination of surgery with chemotherapy was developed. In this curative intent, the macroscopic disease was treated with cytoreductive surgery (CRS) combined with perioperative chemotherapy, including neoadjuvant chemotherapy, hyperthermic intraoperative intraperitoneal chemotherapy, extensive intraoperative peritoneal lavage and early postoperative intraperitoneal chemotherapy AREAS COVERED: This article reviews the mechanisms of the formation of PSM, quantitative estimation of PSM and residual disease, multimodal treatment, value of laparoscopy, prognostic factors and patients' selection for the multimodal therapy. EXPERT OPINION: Recent studies show that CRS plus intraperitoneal chemotherapy applications confer prolonged survival in patients with PSM from colorectal, gastric, ovarian, appendiceal mucinous carcinoma and diffuse malignant peritoneal mesothelioma. The comprehensive treatment is now justified as state-of-the-art for patients with peritoneal metastasis.

Differentiating a large abdominal cystic lymphangioma from multicystic mesothelioma: report of a case.

We report a case of retroperitoneal cystic lymphangioma in a 30-year-old woman who presented with abdominal distention and pain. Imaging studies revealed a large, thin-walled multicystic mass occupying the whole abdomen. Based on a preoperative diagnosis of multicystic mesothelioma, we performed laparotomy, which revealed a tumor arising from the gastropancreatic ligament in the posterior wall of the omental bursa. We resected the tumor completely, without the adjacent viscera. The final pathological diagnosis was cystic lymphangioma, based on the immunohistochemical findings of positive CD31 and CD34 expression, the presence of smooth muscle confirmed by smooth muscle antigen and desmin, and negative calretinin, WT-1 and cytokeratins 5/6 expression. Multicystic mesotheliomas and cystic lymphangiomas are so similar in morphology that immunohistochemical staining should be fully utilized to differentiate them.