Disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis. A clinicopathologic analysis of 109 cases with emphasis on distinguishing pathologic features, site of origin, prognosis, and relationship to "pseudomyxoma peritonei"

Pseudomyxoma peritonei extending to the lower extremity: a case report

Pseudomyxoma peritonei is characterized by mucinous ascites originating from a mucin-producing neoplasm; however, even the definition is still under debate. Tumor deposits extend and ultimately engulf the entire cavity, causing death from cachexia due to limited intestinal movement. Here, we report a unique case of an 80-year-old woman with pseudomyxoma peritonei, which extended to the lower extremity mimicking infectious condition. The patient survived for a long time without bowel obstruction despite having the histologic subtype that has an unfavorable prognosis. The extremity lesion was treated with limited extensive surgery. The origin of the disease and the mechanism of extension to the extremity could not be clarified. Clinicians should be aware of the original disease entity and this unusual presentation and determine its mechanism and the best management strategy.

Primary signet ring cell carcinoma of the appendix: A rare case report

Primary adenocarcinoma of the appendix is a rare malignancythat constitutes < 0.5% of all gastrointestinalneoplasms. Moreover, primary signet ring cell carcinomaof the appendix is an exceedingly rare entity. In the present report, we describe a rare case of primary signet ring cell carcinoma of the appendix with ovarian metastasesand unresectable peritoneal dissemination occurring in a 45-year-old female patient. She was clinically misdiagnosed as torsion of ovarian cyst. She underwent appendicectomy and unilateral salpingo-oophorectomy.Histopathology revealed signet ring cell carcinoma and a right hemicolectomy was done. She then received palliative systemic chemotherapy with 12 cycles of oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX-4). The patient is doing well till today on follow up without progression of disease 10 mo after beginning chemotherapy.

Hyperthermic Intraperitoneal Chemotherapy Following Cytoreductive Surgery Improves Outcome in Patients With Primary Appendiceal Mucinous Adenocarcinoma: A Pooled Analysis From Three Tertiary Care Centers

PURPOSE

Appendiceal mucinous neoplasms (AMN) are a rare heterogeneous group of diseases. In the absence of randomized trials, AMN management is controversial. The goal of this study was to evaluate the impact of hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery on survival in AMN patients.

PATIENTS AND METHODS

Patient data including demographics, pathology, type of therapy, and outcomes were collected from Emory University, the Ohio State University, and Wayne State University databases. One of the three centers did not use HIPEC. Statistical analysis evaluating overall survival (OS) of AMN patients was performed.

RESULTS

Between 1990 and 2010, 163 AMN patients were identified. Histology showed 60 patients had diffuse peritoneal adenomucinosis, 88 had peritoneal mucinous carcinomatosis (PMCA), and 15 had PMCA with indeterminate or discordant features. Complete surgical resection was achieved in 76 patients. HIPEC was used in 79 patients. The median OS was 77 months for patients who received HIPEC compared with 25 months for patients who did not (p < .001). In multivariable analysis, histopathologic subtype (p < .001), complete surgical resection (p < .001), and HIPEC (p < .001) were independent predictors for improved OS. A survival advantage for AMN patients treated at HIPEC-treating centers was observed (p = .0026). After adjusting for HIPEC therapy, no significant survival difference was observed between the non-HIPEC-treating center and the HIPEC-treating centers (p = .094).

CONCLUSION

The addition of HIPEC to cytoreductive surgery likely provides a survival advantage and should be considered in the treatment strategy for AMN.

Transformation of low-grade mucinous neoplasm of the appendix with pseudomyxoma peritonei to high-grade sarcomatoid carcinoma

A 66-year-old man initially underwent appendectomy and cytoreductive surgery for a low-grade appendiceal mucinous neoplasm with pseudomyxoma peritonei. One and a half years later, multiple disseminated lesions developed in rectus abdominis muscle and peritoneal cavity. Biopsy showed histopathological transformation to sarcomatoid carcinoma. This case illustrates that evolution of low-grade pseudomyxoma peritonei to high-grade carcinoma truly develops in some patients. The development of this dedifferentiation appears associated with aggressive behavior and poor clinical outcome.

Guidelines on the use of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with peritoneal surface malignancy arising from colorectal or appendiceal neoplasms

To meet the needs of patients, Canadian surgical and medical oncology leaders in the treatment of peritoneal surface malignancies (psms), together with patient representatives, formed the Canadian HIPEC Collaborative Group (chicg). The group is dedicated to standardizing and improving the treatment of psm in Canada so that access to treatment and, ultimately, the prognosis of Canadian patients with psm are improved. Patients with resectable psm arising from colorectal or appendiceal neoplasms should be reviewed by a multidisciplinary team including surgeons and medical oncologists with experience in treating patients with psm. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy should be offered to appropriately selected patients and performed at experienced centres. The aim of this publication is to present guidelines that we recommend be applied across the country for the treatment of psm.

Mucus containing cystic lesions "mucocele" of the appendix: the unresolved issues

Background. Mucocele of the appendix is a rare condition, the pathological classification and management strategy of which have not been standardized yet. Aim. To report on our management of appendiceal mucocele, highlighting the pitfalls and possible means for avoiding them. Materials and Methods. Our registries were reviewed to retrieve cases of appendiceal mucocele, encountered in the period from July 2008 to May 2013. Results. We had 9 cases, three males and sex females, with a median age of 62 years. Abdominal ultrasound (US) and computerized axial tomography scan (CT) suspected the diagnosis in only one case each. Open appendectomy was done in two cases of mucinous cystadenoma with no further surgery performed, despite the positive margin in one. Laparoscopic appendectomy was done in three cases: mucinous cystadenoma in one case which needed no further surgery, mucinous cystadenocarcinoma with pseudomyxoma peritonei in another, and low grade mucinous tumour in a third case, and all needed subsequent right hemicolectomy. Exploratory laparotomy was done in three cases: of these, synchronous right hemicolectomy was done in one case of mucinous cystadenoma/?mucinous tumour of uncertain malignant potential; in the other two cases, appendectomy only was done for mucinous hyperplasia with carcinoid tumour of the appendix in one case and mucinous cystadenoma/?mucinous tumour of uncertain malignant potential in another. The 9th case was discovered upon laparoscopy for cholecystectomy; when pseudomyxoma peritonei arising from an appendiceal mucocele was found, laparoscopic appendectomy with peritoneal biopsy was then performed instead. Histopathologic diagnostic uncertainty was present in two cases of mucinous cystadenoma where mucinous tumour of uncertain malignant potential was an alternative possibility. Perioperative colonoscopy was performed in only one case and our follow-up programme was defective, with the longest period being 180 days. Conclusion. Mucocele of the appendix should be considered in the differential diagnosis of cystic lesions in the right lower abdomen. Owing to its rarity, it continues to intrigue the surgeon as well as the radiologist and pathologist alike. For mucinous cystadenocarcinoma, right hemicolectomy is usually needed, whereas for hyperplasia and cystadenoma, appendectomy usually suffices if the resection margins are free. For mucinous tumours of uncertain malignant potential and low grade mucinous tumours as well as pseudomyxoma peritonei, the decision is not as simple. As for laparoscopic surgery, no solid proof exists with or against its safety. Although not yet standardized, perioperative colonoscopy and regular follow-up to detect early recurrences should probably be part of the management plan.

The appropriate management of an appendiceal mucocele

Appendicectomy is one of the most commonly performed surgical procedures. Appendiceal mucocele is a relative rare disease, but appropriate management is critical. Indeed, the intact removal of a mucocele represents a curative treatment; conversely, a rupture may result in the spread of epithelial cells throughout the peritoneal cavity (pseudomyxoma peritonei). We report a case of a 61-year-old woman, admitted to our department, who underwent resection of an appendiceal mucocele, focusing, in the discussion, on the clinical and surgical management of this disease.

Case of intraperitoneal sepsis secondary to rupture of the appendix on the background of pseudomyxoma peritonei

INTRODUCTION

Pseudomyxoma peritonei (PMP) is characterised by gelatinous ascites and pools of mucin associated with neoplastic mucinous epithelium within the peritoneal cavity. It can rarely present as acute intraperitoneal sepsis, requiring urgent medical attention.

PRESENTATION OF CASE

A 59-year old male was referred to our centre in February 2014 following a diagnostic laparotomy, which showed jelly-like material with occasional epithelial cells. He was listed for peritonectomy in a month's time at our centre. Three weeks later, he was admitted urgently to our hospital due to generalised abdominal pain and watery diarrhoea. Examination at admission was unremarkable. On the following day, he became haemodynamically unstable and was suspected to have intraperitoneal sepsis due to infected PMP. At emergency laparotomy, we found gross intraperitoneal sepsis and did extensive debulking of tumour, appendectomy and extensive division of adhesions. Another laparotomy was done 24 h later for washout. He was discharged three weeks after.

DISCUSSION

Although we have done 780 peritonectomy procedures, this was the first patient with this presentation of widerspread intraperitoneal sepsis. Continuous mucous production of appendiceal adenoma can lead to appendiceal rupture. The appendix may decompress by perforation and then reseal. However, one episode of appendiceal rupture can cause bacterial contamination of PMP, leading to sepsis.

CONCLUSION

Intraperitoneal sepsis secondary to appendiceal rupture is rare. Hence surgeons may face an emergency of intraperitoneal sepsis during waiting period of planned CRS or as a primary presentation. With combined therapy of CRS and PIC, the prognosis of mucinous appendiceal adenoma is excellent.

Feasibility of radical cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei of appendiceal origin

BACKGROUND AND AIMS

We analyzed the feasibility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with pseudomyxoma peritonei.

MATERIAL AND METHODS

A prospective database comprised 90 consecutive patients with demonstrable pseudomyxoma peritonei collected during 48 months. These patients, referred to our unit for consideration for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, received both cytoreductive surgery and hyperthermic intraperitoneal chemotherapy if possible. We evaluated the factors associated with a successful procedure.

RESULTS

Hyperthermic intraperitoneal chemotherapy was successfully delivered to 56 of 90 patients (62%) with demonstrable pseudomyxoma peritonei. Tumor morphology of low grade (p = 0.013), age under 65 years (p = 0.004), and serum carcinoembryonic antigen level under 5.0 µg/L (p = 0.003) were associated with successful administration of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Mean peritoneal cancer index was lower (18.9 vs 32.6, p < 0.001) and age was younger (54.3 vs 61.6, p = 0.003) in patients who underwent hyperthermic intraperitoneal chemotherapy than in patients who did not. Four patients had complete cytoreductive surgery alone, and 20 patients underwent palliative debulking, but 10 were ineligible for this operation.

CONCLUSIONS

Although the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is currently suggested the standard practice for pseudomyxoma peritonei, not all patients are eligible for this protocol. In this study, hyperthermic intraperitoneal chemotherapy was suitable for 62% of patients with pseudomyxoma peritonei of appendiceal origin.

Systemic chemotherapy (SC) before cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) in patients with peritoneal mucinous carcinomatosis of appendiceal origin (PMCA)

BACKGROUND

The role of SC before CRS/HIPEC for patients with PMCA is unclear. This study explores the effect of SC prior to CRS/HIPEC on overall survival (OS) in patients with PMCA.

METHODS

72 patients with recently diagnosed PMCA who underwent CRS/HIPEC were identified from a prospective database. Thirty patients had SC before CRS/HIPEC (Group 1) and 42 did not (Group 2). Patients who were referred to our center after multiple lines of SC were excluded from this analysis. OS was estimated.

RESULTS

Median follow-up was 3.2 years. Groups were similar regarding lymph node positivity, postoperative SC and rate of complete cytoreduction. Twenty-four (80%) patients in Group 1 and 21 (50%) in Group 2 had high grade histology (HG) (p = 0.01). OS from CRS/HIPEC at 1, 2, and 3 years was 93, 68, 51% in Group 1 and 82, 64, 60% in Group 2, respectively (p = 0.74). Among HG patients 3-year survival was 36% in the SC group vs. 35% in the group without SC (p = 0.67). The 3-year OS for patients with low grade (LG) tumors was 100% in the SC group vs. 79% in the group with no prior SC (p = 0.26). Among patients with signet ring cell (SRC) histology, 1, 2 and 3-year survival was 94, 67 and 22% in the SC group vs. 43, 14, 14% in the group with no SC, respectively (p = 0.028). There were only 6 patients with LG PMCA who received prior SC.

CONCLUSIONS

Preoperative SC could improve the prognosis of patients with high-grade PMCA with SRC histology.

Mucinous epithelial neoplasms of the appendix and pseudomyxoma peritonei

The classification of appendiceal mucinous neoplasms has been controversial, largely focused on a particular subset of low-grade mucinous tumors that, despite their innocuous appearance, can disseminate to the peritoneal cavity as pseudomyxoma peritonei (PMP). Recent WHO classification of these tumors as low-grade appendiceal mucinous neoplasms acknowledges their unique morphologic appearance and biologic behavior. Still, debate about the use of this term and its parameters continues to impede the adoption of consensus classification for appendiceal mucinous neoplasms. The classification of PMP has also been the subject of debate, with international authorities advocating for the use of malignant terminology to describe all grades of PMP, even though some authorities consider low-grade PMP to be dissemination of adenomatous epithelium in the peritoneum. Recent data also emphasize the importance of histologic grade of the peritoneal tumors in defining prognosis of these patients.

Giant appendix or an appendiceal mucocele? Case report of an 11-year-old child

We present an 11-year-old male child with an enormous appendix that was regarded as an appendiceal mucocele. The disorder is very rare and usually appears in middle aged patients. It is a clinical diagnosis. It could cause a variety of symptoms, especially, acute appendicitis and unidentified lesion in the right iliac fossa. According to the reasons, it could be just a curiosity without any relevancy or the sign of a malignant lesion with bad prognostic factors. The histopathological findings prove the origin.

Prognostic significance of single isolated cells with decreased E-cadherin expression in pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) cases can be classified into the prognosis-related subtypes of disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). To investigate the mechanisms of mucinous invasion and the differing prognoses of these two subtypes, we examined the expression levels of proteins involved in cellular adhesion and invasion, including E-cadherin, vimentin, β-catenin, and S100A4, in single isolated tumor cells (SICs) and cohesive cellular strips within mucin pools isolated from DPAM (n = 31) and PMCA (n = 21) patients. In both PMCA and DPAM cases, SICs showed a complete loss of E-cadherin expression, whereas cells in cohesive cellular clusters retained E-cadherin expression. The frequency of high numbers of SICs (>8) in PMCA cases was significantly greater than that in DPAM cases (86% and 26%, respectively) and was correlated with poor progression-free survival (P = 0.019) in a univariate analysis. In both PMP subtypes, strong vimentin expression was identified in most of the SICs but not the cohesive cellular strips. The relatively slow progression of DPAM may be attributable to the smaller number of SICs that lack E-cadherin expression and have increased vimentin expression, whereas the rapid progression of PMCA may be due to larger numbers of these SICs.

A rare cause of ascites: pseudomyxoma peritonei and a review of the literature

Pseudomyxoma peritonei is rare. The rarity is highlighted by the lack of published evidence regarding management. The latest treatments have altered the prognosis of a once incurable disease. This report serves to both raise awareness and critically appraise the literature regarding the latest management.

Hyperthermic intraperitoneal chemotherapy with oxaliplatin as treatment for peritoneal carcinomatosis arising from the appendix and pseudomyxoma peritonei: a survival analysis

Background

Appendiceal peritoneal carcinomatosis (PC) is rare and its long-term prognosis is poor. The aim of this study was to evaluate the results of an aggressive treatment approach used in our institution for the last eight years.

Methods

Data from all patients with PC arising from the appendix were prospectively collected and analyzed. Treatment consisted of complete surgical cytoreduction (CRS), followed by hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin (460 mg/m²) at 43°C over 30 minutes. Ronnett’s histologic classification was used for tumor grading.

Results

Between February 2003 and April 2011, 78 patients underwent laparotomy with curative intent. The mean follow-up period was 33.7 months. A total of 58 patients received HIPEC, but 11 patients could not have CRS and received no HIPEC. Nine patients with a negative second-look surgery also received no HIPEC. The five-year overall survival for the entire cohort was 66.2%; 100% for the negative second-look patients, 77% for the HIPEC patients and 9% for the unresectable patients (P <0.0001). A total of 15 patients (25.9%) had isolated peritoneal recurrence, no patient had visceral recurrence only, and five patients (8.6%) had both. In regards to the five-year disease-free survival for the HIPEC patients, histologic grade (disseminated peritoneal adenomucinosis 100%, peritoneal mucinous carcinomatosis with intermediate features 40%, peritoneal mucinous carcinomatosis 20%; p =0.0016) and completeness of cytoreduction (CCR-0 56%, CCR-1 24%; P =0.0172) were prognostic factors. There was one postoperative mortality. The major complication rate for patients treated with HIPEC was 40%, including intra-abdominal abcess (17%), hemorrhage (12%) and anastomotic leak (10%). One patient in the HIPEC group experienced temporary grade II neuropathy and grade III thrombocytopenia.

Conclusions

This therapeutic approach seems both feasible and safe in selected patients. Recurrence is, however, frequent and represents a challenge.

Clinicopathologic and molecular analysis of disseminated appendiceal mucinous neoplasms: identification of factors predicting survival and proposed criteria for a three-tiered assessment of tumor grade

Previous studies have demonstrated that the prognosis of disseminated mucinous appendiceal neoplasms is highly dependent upon tumor grade. Reflecting this, the 7th edition of the American Joint Committee on Cancer (AJCC) staging system now incorporates a three-tier grading system for prognostic staging of mucinous appendiceal tumors. However, the grading criteria are not well described. In order to address this issue, we evaluated clinicopathologic and molecular features of 219 cases from 151 patients with widely disseminated appendiceal mucinous neoplasia treated at our institution between 2004 and 2012. We identified histologic features that were associated with worse overall survival on univariate analysis: destructive invasion, high cytologic grade, high tumor cellularity, angiolymphatic invasion, perineural invasion, and signet ring cell component (all with P<0.0001). We used these morphologic characteristics to classify neoplasms into three grades: AJCC grade G1 lacked all adverse histologic features; AJCC grade G2 had at least one adverse histologic feature (except a signet ring cell component); and AJCC grade G3 were defined by the presence of a signet ring cell component. Patients with AJCC grade G2 and grade G3 adenocarcinomas had a significantly worse prognosis compared with AJCC grade G1 (P<0.0001 for each). A trend toward worse overall survival was identified for patients with AJCC grade G3 adenocarcinomas compared with AJCC grade G2 adenocarcinomas (P=0.07). Our multivariate analysis found that this three-tier grading system was a significant predictor of outcome (P=0.008), independent of other prognostic variables. After controlling for other prognostic variables, AJCC grade G2 was associated with a 2.7-fold increased risk of death (95% confidence interval (CI), 1.2-6.2) and AJCC grade G3 was associated with a 5.1-fold increased risk of death (95% CI, 1.7-14) relative to grade G1 tumors. Our results indicate that evaluation of a limited set of adverse histologic features allows for the separation of disseminated mucinous neoplasms of appendiceal origin into three morphologically defined and prognostically relevant grades as advocated by the AJCC.

Multicentre study of the learning curve and surgical performance of cytoreductive surgery with intraperitoneal chemotherapy for pseudomyxoma peritonei

Background

The learning curves for cytoreductive surgery with intraperitoneal chemotherapy for treatment of pseudomyxoma peritonei (PMP) were explored between international centres/surgeons to identify institutional or other factors that might affect performance.

Methods

Data from patients with PMP treated with the combined procedure across 33 international centres between 1993 and 2012 were analysed retrospectively. A risk-adjusted sequential probability ratio test was conducted after defining the target outcome as early oncological failure (disease progression within 2 years of treatment), an acceptable risk for the target outcome (odds ratio) of 2, and type I/II error rates of 5 per cent. The risk prediction model was elaborated and patients were evaluated sequentially for each centre/surgeon. The learning curve was considered to be overcome and proficiency achieved when the odds ratio for early oncological failure became smaller than 2.

Results

Rates of optimal cytoreduction, severe postoperative morbidity and early oncological failure were 84·4, 25·7 and 29·0 per cent respectively. The median annual centre volume was 17 (range 6–66) peritoneal malignancies. Only eight of the 33 centres and six of 47 surgeons achieved proficiency after a median of 100 (range 78–284) and 96 (86–284) procedures respectively. The most important institutional factor affecting surgical performance was centre volume.

Conclusion

The learning curve is extremely long, so centralization and/or networking of centres is necessary to assure quality of services. One centre for every 10–15 million inhabitants would be ideal.

Appendiceal mucocele and pseudomyxoma peritonei; the clinical boundaries of a subtle disease

PATIENT

Male, 70 • Male, 84.

FINAL DIAGNOSIS

Appendiceal mucocele and pseudomyxoma peritonei.

SYMPTOMS

-.

MEDICATION

-.

CLINICAL PROCEDURE

-.

SPECIALTY

Surgery.

OBJECTIVE

Rare disease.

BACKGROUND

Mucocele of the appendix is an uncommon cystic lesion characterized by distension of the appendiceal lumen with mucus. Most commonly, it is the result of epithelial proliferation, but it can also be caused by inflammation or obstruction of the appendix. When an underlying mucinous cystadenocarcinoma exists, spontaneous or iatrogenic rupture of the mucocele can lead to mucinous intraperitoneal ascites, a syndrome known as pseudomyxoma peritonei.

CASE REPORT

We report 2 cases that represent the clinical extremities of this heterogeneous disease; an asymptomatic mucocele of the appendix in a 70-year-old female and a case of pseudomyxoma peritonei in an 84-year-old male. Subsequently, we review the current literature focusing to the optimal management of both conditions.

CONCLUSIONS

Mucocele of the appendix is a rare disease, usually diagnosed on histopathologic examination of appendectomized specimens. Due to the existing potential for malignant transformation and pseudomyxoma peritonei caused by rupture of the mucocele, extensive preoperative evaluation and thorough intraoperative gastrointestinal and peritoneal examination is required.

Low Grade Appendiceal Mucinous Neoplasm with Pseudomyxoma Peritonei: An Enigma for Pathologist

Malignant mucinous neoplasms of the appendix is an infrequently encountered entity. Extra-appendiceal spread of these tumor is one of the commonest etiology of pseudomyxoma peritonei, which demands a hightened vigilance in their early diagnosis. Although low-grade appendiceal mucinous neoplasms (LAMNs) largely stay confined to the appendix, but they can spread to the peritoneum as pseudomyxoma peritonei leading to an unpredictable outcome. Due to the rare occurrence of low-grade appendiceal neoplasm only tenuous and limited information is present in the medical literature. We report a case of LAMN with pseudomyxoma peritonei in a 45-year-old male, who presented with the complaints of abdominal distension associated with abdominal pain and constipation. Clinical examinations and computed tomography (CT) scan were suggestive of pseudomyxoma peritonei. Peroperative findings and histopathological examination rendered a conclusive diagnosis of low-grade appendiceal neoplasm. How to cite this article: Qadri S, Alam K, Alam F, Maheshwari V. Low Grade Appendiceal Muci-nous Neoplasm with Pseudomyxoma Peritonei: An Enigma for Pathologist. Euroasian J Hepato-Gastroenterol 2014;4(2):113-116.

Pregnancy after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in pseudomyxoma peritonei

Pseudomyxoma peritonei is usually a benign tumor that is slightly more common in women. However, it requires aggressive surgical treatment and chemotherapy, often compromising future reproductive function. This report presents a case of pregnancy in a 35-year-old woman who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for treatment of pseudomyxoma peritonei. The tumor was diagnosed during a laparoscopic examination on a workup for infertility in 2008. Two months later, she underwent a peritonectomy followed by hyperthermic intraperitoneal chemotherapy and, regarding her will to conceive, ovaries and fallopian tubes were preserved. In March 2011, she went through an in vitro fertilization followed by an uneventful pregnancy and delivered a healthy child 39 weeks later. Ovaries are usually resected during the cytoreductive surgery, since they are common sites for neoplastic implants, and, even when not performed, little is known about the effects of local chemotherapy on female fertility. The largest international survey on this matter only describes seven similar cases. This particular report not only describes a rare condition but also adds to the upcoming discussion about whether ovaries can be preserved in specific situations, therefore keeping the prospect of conceiving after this treatment.

Evaluation of a new staging classification and a Peritoneal Surface Disease Severity Score (PSDSS) in 229 patients with mucinous appendiceal neoplasms with or without peritoneal dissemination

INTRODUCTION

Most classifications of mucinous appendiceal neoplasms (MAN) do not take into consideration the type of primary tumor or the burden of peritoneal disease.

MATERIALS AND METHODS

We conducted a retrospective evaluation of 229 patients with MAN. The severity of their disease was analyzed with the Peritoneal Surface Disease Severity Score (PSDSS) on a five-point scale that included: (1) the primary appendiceal tumor, (2) the type of peritoneal dissemination, and (3) the burden of disease. Overall survival was analyzed according to five tiers of estimated disease severity based on the above parameters.

RESULTS

There were 19, 67, 59, 43, and 41 patients with PSDSS 0, I, II, III, and IV, respectively. One hundred seventy-three patients underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Overall survival was 80.0 months in this group with 5-year survival of 100%, 79.2%, 23.3%, and 6.9% in patients with PSDSS I, II, III, and IV, respectively (P < 0.001). On multivariate analysis, sex and PSDSS stage were identified as independent predictors of survival.

CONCLUSIONS

The PSDSS appears to be an important prognostic indicator in patients with MANs with or without peritoneal dissemination and may improve selection of patients for appropriate therapy from the time of diagnosis.

Perioperative systemic chemotherapy for appendiceal mucinous carcinoma peritonei treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND

The role of systemic chemotherapy (SC) in conjunction with cytoreductive surgery (CS) with hyperthermic intraperitoneal chemotherapy (HIPEC) in appendiceal mucinous carcinoma peritonei (MCP) is unknown.

METHODS

A retrospective review (1999-2011) of MCP patients who had undergone CS/HIPEC with or without perioperative SC.

RESULTS

Twenty-two low-grade MCP patients treated with CS/HIPEC and SC were matched to patients who received CS/HIPEC alone. Median overall survival (OS) was 107 months for patients treated with perioperative SC compared to 72 without (P = 0.46). CS/HIPEC was performed on 109 patients with high-grade MCP: 70 were treated with perioperative SC, while 39 were not. Median OS (22.1 vs. 19.6 months, P = 0.74) and progression-free survival (PFS) (10.9 vs. 7.0 months, P = 0.47) were similar in patients treated with SC compared to CS/HIPEC alone. Progression while on pre-operative SC was seen in eight patients (17%), while four (8%) had a partial response. Treatment with post-operative SC was associated with longer PFS (13.6 months) compared to pre-operative SC (6.8 months, P < 0.01) and CS/HIPEC alone (7.0 months, P = 0.03).

CONCLUSIONS

Post-operative SC appears to improve PFS in patients with high-grade appendiceal MCP treated with CS/HIPEC. In contrast, there is no evidence to support the routine use of perioperative SC in low-grade disease.

The importance of gender in patients with peritoneal metastases of appendiceal origin treated by cytoreduction and intraperitoneal chemotherapy: an analysis of 257 consecutive patients from an Australian centre

BACKGROUND AND OBJECTIVES

In the setting of colorectal cancer, female gender has been associated with superior long-term outcomes. Our aim is to investigate the gender differences for metastatic epithelial neoplasms of the appendix treated by cytoreductive surgery (CS) and intraperitoneal chemotherapy (IPC).

METHODS

The survival outcomes of patients treated with CS/IPC from 1996 to 2013 at St. George Hospital, Sydney, Australia, for peritoneal metastases of appendiceal origin were retrospectively analysed.

RESULTS

Two hundred and fifty-seven consecutive patients were followed for a median of 35.3 months. Baseline characteristics between genders were comparable, including age (p = 0.13) and peritoneal cancer index (p = 0.94). Median overall survival (OS) and progression-free survival (PFS) was not reached (NR) and 44.4 months, with a 3-, 5- and 10-year survival of 82, 74 and 64 %. OS and PFS for females was NR and 50.7 months, compared to NR (p = 0.007) and 31.5 months for males (p = 0.07). Three-, 5- and 10-year survival rates for females were 88, 84 and 72 % compared to 74, 61 and 53 % for males.

CONCLUSION

Observed gender differences for neoplasms of the appendix may direct future research in gender-specific tumour markers and the development of adjuvant therapies to improve patient outcomes.

A weeping umbilical hernia: bilateral ovarian mucinous cystadenoma with disseminated peritoneal adenomucinosis

A young woman was referred to us for the management of an umbilical hernia with macerated overlying skin through which massive ascites was leaking. On examination we found a jelly-like substance seeping out of the opening. A contrast-enhanced CT scan of the abdomen revealed bilateral ovarian cystadenocarcinoma with pseudomyxoma peritonei. The patient underwent cytoreductive surgery along with hysterectomy and bilateral oophorectomy followed by hyperthermic intraperitoneal chemotherapy with mitomycin C. Histopathological examination showed bilateral borderline cystadenoma with peritoneal adenomucinosis. Follow-up at 1 year showed no signs of recurrence.

Melioidosis presenting as pseudomyxoma peritonei: yet another pretense of the great mimicker: an unreported entity

BACKGROUND

Melioidosis, a lethal infectious disease caused by Burkholderia pseudomallei, an important human pathogen in tropical regions, is notorious for its diverse clinical presentations.

METHODS

We report a case of a 55-year-old woman with a history of total abdominal hysterectomy with bilateral salpingo-oophorectomy for ovarian mucinous cystadenocarcinoma five years back, who presented with complaints of chest pain, abdominal distention, and breathlessness for one week. Ultrasound-guided aspiration of the peritoneal free fluid revealed a thick gelatinous material consistent with pseudomyxoma peritonei. Cytologic analysis of the aspirate was negative for malignant cells, but bacterial culture proved positive for Burkholderia pseudomallei.

RESULTS

She was started on ceftazidime, and she improved symptomatically and was discharged on oral doxycycline and chloramphenicol after three weeks of intravenous antibiotic therapy.

CONCLUSION

This case is being reported to emphasize an unusual presentation of melioidosis and the significance of timely appropriate antibiotic therapy.

GNAS is frequently mutated in both low-grade and high-grade disseminated appendiceal mucinous neoplasms but does not affect survival

We analyzed a series of 55 disseminated appendiceal mucinous neoplasms treated at our institution for GNAS and KRAS mutations in an attempt to correlate mutation status with clinicopathological findings and patient survival. GNAS mutations (p.R201H, c.602G>A and p.R201C, and c.602C>T) were identified in 17 (31%) of 55 of disseminated mucinous neoplasms and were found in 8 (35%) of 23 low-grade mucinous neoplasms, 7 (37%) of 19 high-grade mucinous adenocarcinomas lacking a signet ring cell component, and 2 (15%) of 13 high-grade mucinous adenocarcinomas with a signet ring cell component. All 7 mucinous adenocarcinomas composed of pure (>95%) signet ring cells harbored wild-type GNAS. There was no significant association between GNAS mutations and sex and age (both with P > .05) or between GNAS mutations and individual adverse histologic features including cytologic grade, destructive invasion, tumor cellularity, angiolymphatic invasion, perineural invasion, and signet ring cells (all with P > .05). KRAS mutations were identified in 22 (40%) of 55 disseminated mucinous neoplasms. GNAS-mutated disseminated appendiceal mucinous neoplasms more frequently harbored concurrent KRAS mutations compared with GNAS wild-type tumors (65% versus 29%, P = .018). GNAS mutations were not significantly associated with overall survival (both with P > .05). Only overall tumor grade was an independent predictor of overall survival in the multivariate analysis (P = .01). Our results indicate that GNAS mutations are frequently identified in both low-grade and high-grade disseminated appendiceal mucinous neoplasms indicating that GNAS mutation status cannot be used to distinguish between low-grade from high-grade appendiceal mucinous neoplasms.

Secreted mucins in pseudomyxoma peritonei: pathophysiological significance and potential therapeutic prospects

Pseudomyxoma peritonei (PMP, ORPHA26790) is a clinical syndrome characterized by progressive dissemination of mucinous tumors and mucinous ascites in the abdomen and pelvis. PMP is a rare disease with an estimated incidence of 1-2 out of a million. Clinically, PMP usually presents with a variety of unspecific signs and symptoms, including abdominal pain and distention, ascites or even bowel obstruction. It is also diagnosed incidentally at surgical or non-surgical investigations of the abdominopelvic viscera. PMP is a neoplastic disease originating from a primary mucinous tumor of the appendix with a distinctive pattern of the peritoneal spread. Computed tomography and histopathology are the most reliable diagnostic modalities. The differential diagnosis of the disease includes secondary peritoneal carcinomatoses and some rare peritoneal conditions. Optimal elimination of mucin and the mucin-secreting tumor comprises the current standard of care for PMP offered in specialized centers as visceral resections and peritonectomy combined with intraperitoneal chemotherapy. This multidisciplinary approach has reportedly provided a median survival rate of 16.3 years, a median progression-free survival rate of 8.2 years and 10- and 15-year survival rates of 63% and 59%, respectively. Despite its indolent, bland nature as a neoplasm, PMP is a debilitating condition that severely impacts quality of life. It tends to be diagnosed at advanced stages and frequently recurs after treatment. Being ignored in research, however, PMP remains a challenging, enigmatic entity. Clinicopathological features of the PMP syndrome and its morbid complications closely correspond with the multifocal distribution of the secreted mucin collections and mucin-secreting implants. Novel strategies are thus required to facilitate macroscopic, as well as microscopic, elimination of mucin and its source as the key components of the disease. In this regard, MUC2, MUC5AC and MUC5B have been found as the secreted mucins of relevance in PMP. Development of mucin-targeted therapies could be a promising avenue for future research which is addressed in this article.

Recent concepts of ovarian carcinogenesis: type I and type II

Type I ovarian tumors, where precursor lesions in the ovary have clearly been described, include endometrioid, clear cell, mucinous, low grade serous, and transitional cell carcinomas, while type II tumors, where such lesions have not been described clearly and tumors may develop de novo from the tubal and/or ovarian surface epithelium, comprise high grade serous carcinomas, undifferentiated carcinomas, and carcinosarcomas. The carcinogenesis of endometrioid and clear cell carcinoma (CCC) arising from endometriotic cysts is significantly influenced by the free iron concentration, which is associated with cancer development through the induction of persistent oxidative stress. A subset of mucinous carcinomas develop in association with ovarian teratomas; however, the majority of these tumors do not harbor any teratomatous component. Other theories of their origin include mucinous metaplasia of surface epithelial inclusions, endometriosis, and Brenner tumors. Low grade serous carcinomas are thought to evolve in a stepwise fashion from benign serous cystadenoma to a serous borderline tumor (SBT). With regard to high grade serous carcinoma, the serous tubal intraepithelial carcinomas (STICs) of the junction of the fallopian tube epithelium with the mesothelium of the tubal serosa, termed the “tubal peritoneal junction” (TPJ), undergo malignant transformation due to their location, and metastasize to the nearby ovary and surrounding pelvic peritoneum. Other theories of their origin include the ovarian hilum cells.

Significance of signet ring cells in high-grade mucinous adenocarcinoma of the peritoneum from appendiceal origin

Significance of signet ring cells in mucinous adenocarcinoma of the peritoneum from appendiceal origin has never been specifically studied. We retrospectively reviewed cases of mucinous adenocarcinoma of the peritoneum from appendiceal origin (n = 55) and collected clinical follow-up data. Signet ring cells were identified in 29 of 55 cases. No low-grade mucinous adenocarcinoma case (n = 11) had signet ring cells, whereas 29 of 44 high-grade mucinous adenocarcinoma cases did. Cases of high-grade mucinous adenocarcinoma were subdivided into 3 groups: (1) high-grade mucinous adenocarcinoma without signet ring cells (n = 15), (2) high-grade mucinous adenocarcinoma with signet ring cells only within mucin pools (n = 20), and (3) high-grade mucinous adenocarcinoma with signet ring cells invading tissue (n = 9). Overall survival (OS) and progression-free survival were subsequently evaluated. Five-year OS for cases of high-grade mucinous adenocarcinoma without signet ring cells and high-grade mucinous adenocarcinoma with signet ring cells within mucin pools were similar at 31.8% (SE, 14.4%) and 35.8% (SE, 13.9%), respectively. A significant survival difference was seen for cases of high-grade mucinous adenocarcinoma with signet ring cells invading tissue with a median OS of 0.5 years versus 2.9 and 2.4 years (P = .04 and P = .03), respectively, for cases of high-grade mucinous adenocarcinoma without signet ring cells and high-grade mucinous adenocarcinoma with signet ring cells within mucin pools. Finding signet ring cells floating in extracellular mucin pools made no prognostic difference when compared with cases of high-grade mucinous adenocarcinoma without signet ring cells. In contrast, high-grade mucinous adenocarcinoma with signet ring cells invading tissue was significant for worse survival, and thus, we propose reporting signet ring cell tissue invasion particularly when extensive.

Controversy and consensus on the management of patients with pseudomyxoma peritonei

OPINION STATEMENT

Pseudomyxoma peritonei and peritoneal carcinomatosis derived from appendiceal epithelial tumors are controversial entities from classification to treatment. For the former entity, multiple classification systems have been attempted to distinguish indolent from more aggressive subtypes. The treatment of the low grade variants is managed with serial cytoreduction surgery, with data indicating possible, but unproven, benefit from heated intraperitoneal chemotherapy (HIPEC). There is no consensus on the role of cytoreduction and HIPEC for the management of the more aggressive histologic variants and peritoneal carcinomatosis. Currently, we believe systemic chemotherapy is the standard of care for patients with the high grade variants and peritoneal carcinomatosis.

[Peritoneal pseudomyxoma: an overview emphasizing pathological assessment and therapeutic strategies]

Pseudomyxoma peritonei is a clinical entity characterized by a gelatinous ascite associated with mucinous tumor deposits spreading on peritoneal surface and potentially invading abdominal organs. It is considered as a tumor process linked, in most of cases, to a mucinous appendiceal neoplasm. Pseudomyxoma peritonei may benefit from a therapeutic strategy combining cytoreductive surgery and intra-peritoneal chemotherapy, which has led to a major prognosis improvement. Different classifications are available and the last one corresponds to the WHO 2010 version, which individualizes pseudomyxoma peritonei in two classes: low grade and high grade mucinous carcinoma. The very low frequency of this entity and its specific therapeutic strategy need specific health care centres, as well as physicians and pathologists collaborating through dedicated networks. The aim of this article is to summarize the pathology, causes, mechanisms and therapeutic approaches of pseudomyxoma peritonei, as well as their interfaces with dedicated networks.

Cytoreductive surgery plus perioperative intraperitoneal chemotherapy in pseudomyxoma peritonei: aspects of the learning curve

BACKGROUND

Cytoreductive surgery (CRS) plus perioperative intraperitoneal chemotherapy is a highly invasive treatment of peritoneal metastasis and requires many surgical procedures before mastering. The aim of this study was to estimate how many procedures are needed before stabilization can be seen in surgical outcome (R1 surgery, adverse events and bleeding) in patients with pseudomyxoma peritonei (PMP).

PATIENTS AND METHODS

All 128 patients with PMP who were treated with CRS alone or CRS plus perioperative intraperitoneal chemotherapy between 2003 and 2008 at the Uppsala University Hospital, Uppsala, Sweden, were included. The learning curve was calculated using the partial least square (PLS) and cumulative sum control chart (CUSUM) graph. Two groups were formed based on the results of the learning curve. The learning curve plateau was considered the same as the stabilization in the CUSUM graph. Group I consisted of patients included during the learning period (n = 73) and Group II of patients treated after the learning period ended (n = 55). Comparisons between the groups were made on surgical outcome, survival and adverse events.

RESULTS

Stabilization was seen after 220 ± 10 procedures. A higher occurrence of R1 surgery was seen in Group II (80%) compared to Group I (48%; P = 0.0002). Overall survival increased at four years after surgery in Group II compared to Group I (80% vs. 63%; P = 0.02).

CONCLUSION

CRS plus perioperative intraperitoneal chemotherapy is a highly demanding procedure that requires more than 200 procedures before optimisation in surgical outcome is seen.

Pseudomyxoma peritonei: a clinical case of this poorly understood condition

BACKGROUND

Pseudomyxoma peritonei is an uncommon condition with an estimated incidence of one to two per million (worldwide) per year. It is characterized by the peritoneal deposition of mucinous tumors, most commonly of the appendix, and occasionally from the ovary, coupled by mucinous ascites.

CASE PRESENTATION

We report the case of a 76-year-old woman who presented with increased abdominal girth and dyspnea for 2 weeks. She was diagnosed as a case of pseudomyxoma peritonei. She was submitted to right oophorectomy, omentectomy, and pseudomyxoma debulking. The histology was compatible with a mucinous tumor of colorectal/appendicular origin. Chemotherapy was not administered because of her functional status. Two years and 8 months later, she refers with postprandial fullness and has moderate ascites.

Concurrent MCL1 and JUN amplification in pseudomyxoma peritonei: a comprehensive genetic profiling and survival analysis

Pseudomyxoma peritonei (PMP) is a rare abdominal malignancy. We hypothesized that next-generation exomic sequencing would identify recurrent mutations that may have prognostic or therapeutic implications. Ten patients were selected on the basis of availability of tissue and adequate follow-up. They were treated at our institution between September 2002 and August 2004. Using next-generation exomic sequencing, we tested for mutations in 236 cancer-related genes in formalin-fixed paraffin-embedded slides. MCL1 amplification was additionally tested with immunohistochemical staining. Detectable mutations were found in 8 patients (80%). Seven patients harbored a KRAS mutation, most commonly involving codon 12. Four GNAS mutations (R201H/R201C substitutions) were also detected. MCL1 and JUN were concurrently amplified in three patients. One patient with MCL1 and JUN amplification had concurrent amplification of MYC and NFKBIA. ZNF703 was amplified in one patient. Patients with MCL1 amplification were also found to express MCL1 with immunohistochemistry, but MCL1 expression was also detected in some patients without amplification. To our knowledge, we are the first to report MCL1 and JUN coamplification in PMP. Expression of MCL1 may not be completely dependent on amplification. The prognostic and therapeutic implications of these recurrent mutational events are the subject of ongoing investigation.

Current concepts in pseudomyxoma peritonei

Each year, about two per million individuals will be diagnosed with pseudomyxoma peritonei, a disease characterised by the intra-abdominal growth of neoplastic mucin-secreting cells on peritoneal surfaces. The distribution of the disease within the abdomen is not random but depends on physiological principles. Most cases derive from neoplasms of the appendix. In the past, the ovary was considered a common primary site. However, we now know that the ovary is only rarely the source of pseudomyxoma, and that lesions which would previously have been called "borderline mucinous tumours of the ovary" are typically metastatic from the appendix. The grade of the neoplastic cells in pseudomyxoma is an important prognostic factor, but unfortunately there is no consensus on terminology. An international expert group of pathologists and clinicians is currently working on the harmonisation of terminology in this field. Expertise in the management of pseudomyxoma can be achieved by concentrating the treatment of patients in specialised centres or through the development of networks.