Retrospective multicenter study of a clinicopathologic analysis of pseudomyxoma peritonei associated with ovarian tumors (KGOG 3005)

Origin and survival outcomes of Pseudomyxoma peritonei-A retrospective study

BACKGROUND

Pseudomyxoma peritonei (PMP) is an unusual clinical condition typically presenting with widespread mucinous neoplastic lesions within the peritoneum resulting in gelatin material-rich ascites. It was first described by Werth in 1884. Ever since, its clinical presentation, definition, site of origin, and prognosis have been a subject of debate. However, many histopathologic, immunohistochemical, and genetic studies have attempted to locate the primary lesion in the appendix in both genders.

OBJECTIVES

To analyze the histological origin and survival outcomes of pseudomyxoma peritonei in patients treated at a regional cancer center.

MATERIALS AND METHODS

Fifteen cases of PMP were diagnosed during the five-year study period. The demographic and clinicopathological details were retrieved; the slides were reviewed and histological parameters reassessed. Descriptive statistics were used to express proportions. Continuous variables were recorded as mean (SD) or median (IQR). Kaplan-Meier (KM) curve was used to estimate overall survival.

RESULTS

Mean age for PMP was found to be 47.5 years for low grade Mucinous Carcinoma Peritonei (MCP), 54.2 years for high grade MCP, and 58 years for high grade MCP with signet ring cells. Most common overall presentation was abdominal distension in 53.3% (8/15) of cases, followed by acute appendicitis in 20% (3/15) cases. PMP was detected synchronous with the primary tumor in 9/15 cases (60%). Primary lesion in the appendix was grossly identified in 7/15 cases, while it was not explored in the remaining eight cases. Yet, by combined clinical, radiological, histopathological, and immunohistochemical analysis, we identified that most of the cases (14/15) had an appendiceal origin (93.3%). The overall survival for 12 months was 50% and for 18 months was 37%.

CONCLUSION

The surgeon and radiologist may well bear in mind the most common possibility of an appendiceal origin for PMP and resect the appendix, irrespective of the presence of a grossly or radiologically detectable lesions. We emphasize that immunohistochemistry helped to detect the site of origin even when the primary was occult.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy to Treat Pseudomyxoma Peritonei of Ovarian Origin: A Retrospective French RENAPE Group Study

BACKGROUND

Ovarian pseudomyxoma peritonei (OPMP) are rare, without well-defined therapeutic guidelines. We aimed to evaluate cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) to treat OPMP.

METHODS

Patients from the French National Network for Rare Peritoneal Tumors (RENAPE) database with proven OPMP treated by CRS/HIPEC and with histologically normal appendix and digestive endoscopy were retrospectively included. Clinical and follow-up data were collected. Histopathological and immunohistochemical features were reviewed.

RESULTS

Fifteen patients with a median age of 56 years were included. The median Peritoneal Cancer Index was 16. Following CRS, the completeness of cytoreduction (CC) score was CC-0 for 9/15 (60%) patients, CC-1 for 5/15 (33.3%) patients, and CC-2 for 1/15 (6.7%) patients. The median tumor size was 22.5 cm. After pathological review and immunohistochemical studies, tumors were classified as Group 1 (mucinous ovarian epithelial neoplasms) in 3/15 (20%) patients; Group 2 (mucinous neoplasm in ovarian teratoma) in 4/15 (26.7%) patients; Group 3 (mucinous neoplasm probably arising in ovarian teratoma) in 5/15 (33.3%) patients; and Group 4 (non-specific group) in 3/15 (20%) patients. Peritoneal lesions were OPMP pM1a/acellular, pM1b/grade 1 (hypocellular) and pM1b/grade 3 (signet-ring cells) in 13/15 (86.7%), 1/15 (6.7%) and 1/15 (6.7%) patients, respectively. Disease-free survival analysis showed a difference (p = 0.0463) between OPMP with teratoma/likely-teratoma origin (groups 2 and 3; 100% at 1, 5, and 10 years), and other groups (groups 1 and 4; 100%, 66.6%, and 50% at 1, 5, and 10 years, respectively).

CONCLUSION

These results suggested that a primary therapeutic strategy using complete CRS/HIPEC for patients with OPMP led to favorable long-term outcomes.

Prevalence and incidence of pseudomyxoma peritonei in urban China: A nationwide retrospective cohort study

BACKGROUND

Pseudomyxoma peritonei (PMP) is an extremely rare condition. Information regarding the disease burden of PMP in developing countries is limited. This study aimed to determine the epidemiology of PMP in China.

METHODS

PMP data were extracted from the national databases of Urban Basic Medical Insurance. All cases were identified using the International Classification of Diseases (ICD) codes and Chinese diagnostic terms. The national prevalence from 2012 to 2016 and incidence in 2016 were estimated.

RESULTS

In total, 153 patients with PMP were identified. The crude prevalence of PMP in 2016 was 2.47 (95% confidence interval [CI] 1.71 to 3.23) per million person-year, with a higher prevalence in females than males. Prevalence increased with age, with the first peak in those aged 15-29 years and the highest in those aged >80 years. The crude incidence of PMP in 2016 was 1.19 (95% CI 0.59 to 1.78) per million person-years. Similar to the prevalence, the rates were higher in women than in men. The incidence also increased with age, with the highest prevalence in those aged >80 years. Besides, the most frequent comorbidities before and after the first diagnosis of PMP were unspecified secondary malignancies and malignancies of unspecified sites, followed by abdominal malignant tumours.

CONCLUSIONS

The rate of PMP was lower in mainland China than in European countries and increased with advancing age. Women were more likely to have PMP than men. Furthermore, an insufficient understanding of this rare disease presents a major challenge in accurately evaluating the disease burden.

Appendiceal mucinous neoplasm mimics ovarian tumors: Challenges for preoperative and intraoperative diagnosis and clinical implication

OBJECTIVE

The aim of this study was to investigate the clinicopathological characteristics of appendiceal mucinous neoplasm that had been preoperatively misdiagnosed as a mucinous ovarian tumor and to discuss the clinical impacts of misdiagnosis.

METHODS

Seventy-eight patients with a final pathologic diagnosis of appendiceal mucinous neoplasm during a 10-year period were retrospectively reviewed. All patients were diagnosed with ovarian tumor before treatment. A univariate analysis was performed to evaluate predictors of the diagnostic accuracy of a frozen section.

RESULTS

The patients' median age was 61 years (range, 21-82 years), and most were diagnosed as low-grade appendiceal mucinous neoplasm (LAMN) (84.62%). The diagnostic concordance between the frozen section and the final pathology was 56.92%. The most consistent diagnosis was LAMN (64.14%). Univariate analysis indicated that maximal diameter of the ovarian tumor (unilateral), laterality of the ovarian tumors (unilateral or bilateral), and frozen section site (appendix or extra-appendix) significantly correlated with the accuracy of frozen section diagnosis (all p < 0.05). Although the diagnostic discordance between the frozen section and the final pathology was 43.08%, only one patient was clinically impacted because of suboptimal surgery.

CONCLUSION

Appendiceal mucinous neoplasm should be considered as a differential diagnosis of pelvic mass in women. For patients who do not require fertility-sparing surgery, excision and frozen section of the bilateral ovaries and appendix regardless of the appearance of the appendix might improve the diagnosis. For older patients with peritoneal dissemination, appropriate cytoreductive surgery is recommended to reduce the clinical impact of misdiagnosis.

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.

Management of a Ruptured Mucinous Mesenteric Cyst with Hyperthermic Intraperitoneal Chemotherapy

Mesenteric cysts are rare intra-abdominal cysts that are generally regarded as benign, and the incidence of malignancy is often cited to be 3%. The typical recommendation for treatment is complete excision to minimize recurrence. Excision can be performed laparoscopically, but this can lead to intra-abdominal dissemination of the cyst contents. There has been one case report describing the development of pseudomyxoma peritonei following rupture of a mesenteric cyst. We describe the treatment and outcome of a patient who underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for the treatment of an incompletely resected mucinous cystadenocarcinoma originating from the colonic mesentery.

Clinicopathological features and prognosis of pseudomyxoma peritonei

The aim of this study was to evaluate the effects of treatment and the factors influencing the postoperative recurrence and survival time for pseudomyxoma peritonei (PMP). A total of 39 patients with PMP who received treatment were analyzed in The General Hospital of PLA (Beijing, China) between 2002 and 2011. The patients received cytoreductive surgery (CRS) and 25 cases of PMP recurred. Seven patients received postoperative hyperthermic intraperitoneal chemoperfusion (HIPEC). The median follow-up was 40 months. There were eight mortalities in this period. The 5- and 10-year survival rates were 89.0 and 35.0%, respectively. The medians of overall survival (OS) and recurrence time were 37 and 4 months, respectively. Multivariate analyses revealed that pathological subtype was able to influence the recurrence (P=0.042) and OS (P=0.033) times, as an independent prognostic factor. HIPEC was significantly associated with postoperative recurrence time (P=0.017). Patients with disseminated peritoneal adenomucinosis had a more favorable prognosis. CRS combined with HIPEC was able to extend the postoperative recurrence time for patients with PMP.

[Complications of presumed benign ovarian tumors]

The main risk factor of adnexal torsion is a previous adnexal torsion (LE3). There is no clinical, biological or radiological sign that may exclude the diagnosis of adnexal torsion (LE3). The presence of flow at color Doppler imaging does not allow exclusion of the diagnosis (LE2). An emergent laparoscopy is recommended for adnexal untwisting (Grade B), except in postmenopausal women where oophorectomy is recommended (grade C). A persistent black color of the adnexa after untwisting is not an indication for systematic oophorectomy (grade C), since a functional recovery is possible (LE3). Ovariopexy is not routinely recommended following adnexal untwisting (grade C). The clinical signs of intra-cystic hemorrhage and those of rupture of the corpus luteum are not specific (LE4). MRI is not recommended to confirm the diagnosis of intra-cystic hemorrhage (grade C). Malignant transformation of an ovarian cyst is very rare. The presence of a benign ovarian cyst is not associated with an increased risk of ovarian cancer at long-term follow-up (LE2). For these women, an ultrasound follow-up is not recommended (grade C). Dermoid ovarian cyst containing nerve tissue can trigger the production of pathogenic auto-antibody-anti-NMDA, leading to encephalitis. A high proportion of thyroid tissue in a mature teratoma (struma ovarii) may cause hyperthyroidism.

Female patients with pseudomyxoma peritonei: a single-institution clinicopathologic study of 35 cases

PURPOSE

To explore clinicopathologic/prognostic aspects of pseudomyxoma peritonei (PMP).

METHODS

We reviewed records of 35 female patients with PMP treated at a single institution.

RESULTS

Patients' median age was 57.0 years (range 35.0-71.0 years). Their median pre-surgery level of carbohydrate antigen 19-9 (CA-199) was 80.95 U/ml (range 0.00-1,562.10 U/ml); of carbohydrate antigen 12-5 (CA-125), 44.00 U/ml (range 0.90-231.20 U/ml); and of carcinoembryonic antigen (CEA), 17.20 ng/ml (range 2.04-211.60 ng/ml). Of the 35 patients, 23 (65.7 %) underwent cytoreductive surgery (CRS) by gynecological oncologists and 12 (34.3 %) underwent non-CRS surgeries by general gynecologists or surgeons, including one patient who refused surgical treatment beyond a diagnostic laparoscopy. After surgery, 18 patients (51.4 %) had residual lesions, 11 (31.4 %) had complete lesion removal and 6 (17.1 %)had insufficient information on residual lesion; 21 (60.0 %) had appendiceal-based tumors and 12 (34.3 %) had ovarian-based tumors. Median follow-up time was 37 months (range 1-148 months), during which 28 patients (80.0 %) had relapsed. By the end of the study, 12 patients (34.3 %) died of PMP, 16 (45.7 %) survived with disease, and 7 (20 %) survived without disease. Median progress-free survival (PFS) was 12 months (range 0.5-114.0 months). Median overall survival time was 42 months (range 5-150 months). Ovarian tumor origin, post-surgery residual lesions, preoperative CA199 > 258.9 U/ml and CA125 > 70.6 U/ml were independent predictors of PFS.

CONCLUSIONS

PMP is rare in women, and has a poor long-term survival rate. Multi-center cooperation to gather more cases is needed to explore its behavior and proper treatment.

Pseudomyxoma Peritonei: A Rare Cause of Oliguric Acute Kidney Injury

Pseudomyxoma peritonei is a rare clinical condition that causes the accumulation of mucinous ascites, which gradually results in the compression of intra-abdominal organs. Most published reports of pseudomyxoma peritonei concern the mass effect of the resulting ascites, which presents as abdominal pain or intestinal ileus in severe cases. However, few reports of renal complications of the disease have been published. Here, we present a case of oliguric acute kidney injury caused by external compression by pseudomyxoma peritonei. After decompression with external drainage, the patient's renal function rapidly improved.

Pseudomyxoma peritonei as an intractable disease and its preoperative assessment to help improve prognosis after surgery: A review of the literature

Pseudomyxoma peritonei (PMP) is a rare and intractable disease with an estimated incidence of one per million population per year. Many aspects of PMP need to be fully and precisely understood; these include its preoperative assessment, i.e. diagnosis, early diagnosis, pathologic classification, and staging according to the peritoneal cancer index, and its surgical treatment. This review focuses on elements of preoperative assessment and surgery using the Sugarbaker procedure to help improve the prognosis for patients with PMP. Accurate data on the incidence of PMP must be based on large populations rather than estimates, and much work needs to be done especially in China. Special attention should be paid to its preoperative assessment. Also proposed here are steps to manage PMP with an emphasis on preoperative assessment.

Pseudomyxoma peritonei of 92 Chinese patients: Clinical characteristics, pathological classification and prognostic factors

AIM: To assess the clinicopathologic features and its relationship with prognosis of pseudomyxoma peritonei (PMP) in Chinese patients.

METHODS: The clinicopathologic features and follow-up data of 92 patients with PMP were reviewed and retrospectively analyzed. The cases were categorized into three groups: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), and peritoneal mucinous carcinomatosis with intermediate or discordant features (PMCA-I/D). The log-rank test was used to analyze survival for each group and various clinicopathological parameters. Multivariate Cox proportional-hazard models were constructed to determine the important factors associated with survival.

RESULTS: The median age at diagnosis was 51.9 years (range: 22-76 years). The median follow up was 124 mo. The 3-, 5- and 10-year survival rates were 74.0%, 67.4% and 49.1%, respectively. There were 49 (53.2%) patients with DPAM, 26 (28.3%) with PMCA-I and 17 (18.5%) with PMCA. Patients with DPAM, PMCA-I/D and PMCA exhibited statistically significant difference in survival (P = 0.001). The 3 year survival for DPAM, PMCAI/D and PMCA was 97.0%, 80.0% and 67.0%, respectively; the 5 year survival was 80.0%, 67.0% and 50.0%, respectively; and the 10 year survival was 65.0%, 28.0% and 14.0%, respectively. Survival rate was significantly lowest in patients < 40 age years of age (P = 0.011). Appendiceal tumor and extra-ovarian parenchymal organ involvement were significantly related to overall survival. Patients with appendiceal mucinous adenocarcinoma (MACA) showed the significantly poorer prognosis (P = 0.011). Multivariate analysis showed that pathological classification, age, appendiceal tumor were significant related to overall survival.

CONCLUSION: The clinical process “PMP” should be pathologically classified into DPAM, PMCA and PMCA-I/D. Pathological classification, age, appendiceal MACA are survival independent predictors in Chinese patients with PMP.

Histological origin of pseudomyxoma peritonei in Chinese women: Clinicopathology and immunohistochemistry

AIM: To investigate the histological origin of pseudomyxoma peritonei (PMP) in Chinese women.

METHODS: The clinical and pathological data were reviewed for 35 women with PMP, and specimens of the peritoneal, appendiceal and ovarian lesions of each patient were examined using the PV-6000 immunohistochemistry method. Antibodies included cytokeratin (CK)7, CK20, mucin (MUC)-1, MUC-2, carbohydrate antigen (CA)-125, estrogen receptor (ER), and progesterone receptor (PR).

RESULTS: Abundant colloidal mucinous tumors were observed in the peritoneum in all 35 cases. Thirty-one patients had a history of appendectomy, 28 of whom had mucinous lesions. There was one patient with appendicitis, one whose appendix showed no apparent pathological changes, and one with unknown surgical pathology. Ovarian mucinous tumors were found in 24 patients. The tumors were bilateral in 13 patients, on the right-side in nine, and on the left side in two. Twenty patients had combined appendiceal and ovarian lesions; 16 of whom had undergone initial surgery for appendiceal lesions. Four patients had undergone initial surgery for ovarian lesions, and relapse occurred in these patients at 1, 11, 32 and 85 mo after initial surgery. Appendiceal mucinous tumors were found in each of these four patients. Thirty-three of the 35 patients showed peritoneal lesions that were positive for CK20 and MUC-2, but negative for CK7, MUC-1, CA125, ER and PR. The expression patterns in the appendix and the ovary were similar to those of the peritoneal lesions. In one of the remaining two cases, CK20, CK7 and MUC-2 were positive, and MUC-1, CA125, ER and PR were negative. The ovaries were not resected. The appendix of one patient was removed at another hospital, and no specimen was evaluated. In the other case, the appendix appeared to be normal during surgery, and was not resected. Peritoneal and ovarian lesions were negative for CK20, MUC-2, CK7, MUC-1, CA125, ER and PR.

CONCLUSION: Most PMP originated from the appendix. Among women with PMP, the ovarian tumors were implanted rather than primary. For patients with PMP, appendectomy should be performed routinely. The ovaries, especially the right ovaries should be explored.

Identifying prognostic factors in Japanese women with pseudomyxoma peritonei: a retrospective clinico-pathological study of the Tohoku Gynecologic Cancer Unit

Pseudomyxoma peritonei (PMP) is a rare condition of mucinous ascites associated mainly with mucinous tumors of appendix or ovary. PMP often recurs after treatment and may eventually cause death by abdominal visceral dysfunction via compression with mucinous ascites. Although radical peritonectomy and hyperthermic intra-peritoneal chemotherapy are becoming popular globally, the optimal treatment of PMP has not been established in Japan. We conducted a retrospective multicenter study to clarify the optimal treatment and the prognostic factors of PMP. A total of 23 patients with PMP were analyzed in the Tohoku Gynecologic Cancer Unit (TGCU). Clinical and follow-up data were retrieved and a central pathology review was performed. The median follow-up period was 46 months. Eleven patients underwent complete resection. There were 7 deaths out of 13 recurrences/progressions in this period. All the recurrence/progression was confined to the abdomen. Unexpectedly, neither radical peritonectomy nor hyperthermic intra-peritoneal chemotherapy had been performed, indicating that both radical peritonectomy and hyperthermic intra-peritoneal chemotherapy are not yet popular in Japan. The medians of overall survival and disease-free period were 166 months and 30 months, respectively. Univariate and multivariate analyses revealed that the only prognostic factor was macroscopic residual tumor (P=0.022). Although chemotherapy was not a prognostic factor (P=0.16), those who received intra-peritoneal chemotherapy tended to have a better prognosis than those who received systemic or no chemotherapy (P=0.064). In conclusion, the macroscopic residual tumor is an important prognostic factor in Japanese patients with PMP.

SGO White Paper on ovarian cancer: etiology, screening and surveillance

Ovarian cancer is a heterogeneous, rapidly progressive, highly lethal disease of low prevalence. The etiology remains poorly understood. Numerous risk factors have been identified, the most prominent involving an inherited predisposition in 10% of cases. Women with germline mutations associated with Hereditary Breast/Ovarian Cancer and Lynch syndromes have dramatically elevated risks (up to 46% and 12%, respectively). Risk-reducing salpingo-oophorectomy is the best method to prevent ovarian cancer in these high-risk women. Significant risk reduction is also seen in the general population who use oral contraceptives. Since up to 89% patients with early-stage disease have symptoms prior to diagnosis, increased awareness of the medical community may facilitate further workup in patients who otherwise would have had a delay. Despite enormous effort, there is no proof that routine screening for ovarian cancer in either the high-risk or general populations with serum markers, sonograms, or pelvic examinations decreases mortality. Further evaluation is needed to determine whether any novel biomarkers, or panels of markers, have clinical utility in early detection. Prospective clinical trials have to be designed and completed prior to offering of any of these new diagnostic tests. CA125 is currently the only biomarker recommended for monitoring of therapy as well as detection of recurrence. This commentary provides an overview on the background, screening and surveillance of ovarian cancer.

Ovarian cystadenocarcinoma and pseudomyxoma peritonei

BACKGROUND

Mucoceles resulting from cystadenomas of the ovary are uncommon. Although rare, rupture of the mucoceles can occur without causing any abdominal issue. This report concerns an unusual and interesting case of the right ovary associated with liver, spleen and kidney cysts.

CASE PRESENTATION

A case of ruptured mucocele resulting from cystadenoma of the ovary occurred in a 63-year-old woman. The patient underwent x-ray, ultrasound and a CT scan. Localised pseudomyxoma peritonei associated with adenocarcinoma of the right ovary was diagnosed. The patient underwent resection of the ovary, uterus, uterine tube and appendix with excision of the mesenteric lymph nodes and removal of about 5000 ml of yellowish mucoid jelly. She was free of symptoms at 1-year follow-up.

CONCLUSIONS

Pseudomyxoma peritonei may occur in patients with ovarian cystadenocarcinoma. In such patients, the ovary should be investigated and transvaginal ultrasound can be carefully performed in cases of ruptured mucoceles and localised pseudomyxoma peritonei. Surgical intervention is the current choice of management.

Bevacizumab for the Treatment of Non-Resectable Pseudomyxoma peritonei Associated with Mucinous Ovarian Tumor of Low Malignant Potential - A Comparison of Two Cases

Pseudomyxoma peritonei (PMP) is a rare tumor syndrome that can be diagnosed in association with mucinous ovarian tumors of low malignant potential. Surgical debulking is the primary treatment modality as chemotherapy has generally proven ineffective in this slowly progressive tumor. When patients with PMP are not surgical candidates, there is no effective treatment, and patients will die of progressive disease. We report two patients with PMP with associated mucinous ovarian tumor of low malignant potential treated with Bevacizumab therapy. Both patients demonstrated disease response to single agent Bevacizumab therapy. One patient had a prolonged response while on therapy, remained stable for 6 months when treatment was held, and then after progressing responded to a second course of therapy. We discuss here (1) the clinical features which may predict a better response to Bevacizumab therapy, and (2) evidence for the use of chemotherapy for inoperable PMP. These cases suggest that Bevacizumab may represent a rare effective therapy for patients with inoperable PMP with ovarian involvement and should be considered for clinical trials in this patient population.