Incidental finding of Psuedomyxoma Peritonei in Malignant Peripheral Nerve Sheath Tumour.

Psuedomyxoma peritonei is an infrequent clinical entity characterised by intraperitoneal mucinous/gelatinous ascites produced by the cancerous cells. It has been associated with gastrointestinal, gynaecological, lung and breast tumours. It is commonly asymptomatic and is most often detected incidentally on abdominopelvic imaging or laparoscopy. Higher histological grade of the tumour shows increased metabolic activity on 18F-Fluorodeoxyglucose (FDG) positron-emission tomography (PET) computed tomography (CT). It has been rarely reported in patients with sarcoma. We hereby present an interesting case of incidentally diagnosed pseudomyxoma peritonei on 18FDG PET-CT scan of a patient with soft tissue sarcoma of peripheral nerve sheath.

A case of pseudomyxoma peritonei arising from a perforated intraductal papillary mucinous neoplasm that underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Pseudomyxoma peritonei (PMP) of pancreatic origin arising from an intraductal papillary mucinous neoplasm (IPMN) is rare. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has been established as the optimal treatment for PMP. However, the benefits and safety of CRS with HIPEC for treating PMP of pancreatic origin remain unclear. Herein, we describe a case of PMP of pancreatic origin that was treated with CRS and HIPEC without postoperative complications. A 75-year-old woman was referred to our department. Computed tomography (CT) revealed a multilocular cystic tumor in the pancreatic tail, notable mucinous ascites in the abdominal cavity, and scalloping of the liver and spleen. CT did not reveal the appendix, and the ovaries were normal in size. The patient was diagnosed with PMP of pancreatic origin, and CRS and HIPEC were performed. Intraoperatively, the pancreatic tumor was perforated, and there was a large amount of mucinous ascites. We performed distal pancreatectomy in addition to CRS and HIPEC, with no intraoperative complications. The postoperative course was uneventful, and the patient survived after 6 months without recurrence. CRS with HIPEC may be a feasible treatment option for PMP of pancreatic origin.

Confined Low Grade Appendiceal Mucinous Neoplasm With Coexisting Distant Metastasis.

BACKGROUND/AIM: Appendiceal mucinous neoplasms (AMNs) are tumors with dysplastic mucinous epithelium, a pushing growth pattern but no infiltrative invasion to the appendiceal wall. Some AMNs are associated with pseudomyxoma peritonei, characterized by intraperitoneal mucinous involvement. Recent studies have demonstrated that LAMNs confined to the appendix have low or no risk for disease recurrence, progression, and peritoneal involvement during follow up. CASE REPORT: Here, we present two extremely rare cases with confined low grade appendiceal mucinous neoplasm (pTis and pT3) and simultaneous extraperitoneal subcutaneous or ovary involvement at the time of diagnosis. CONCLUSION: Our cases demonstrate that although the primary tumor is limited to the appendix, coexisting distant metastasis may occur on very rare occasions.

The Cancer Diaspora: A Rare Case of Pseudomyxoma Peritonei of Appendiceal Origin.

Pseudomyxoma peritonei (PMP) is a rare clinical entity characterized by widespread mucinous implants in the peritoneal cavity. Commonly seen in females in their 50s, PMP typically originates from ruptured appendiceal mucoceles that find refuge in the peritoneal space. Rarely, PMP may originate from the ovary, stomach, colon, or pancreas. Pseudomyxoma peritonei of colorectal origin is more malignant and has a lower survival rate. We report a case of a 59-year-old Hispanic woman with PMP who presented to the emergency room with a 3-month history of progressive abdominal distention. Pseudomyxoma peritonei was confirmed by computed tomography (CT) scan of the abdomen and pelvis and histopathology, and the patient underwent partial cytoreductive surgery. Given her Eastern Cooperative Oncology Group (ECOG) performance status of 1 despite extensive carcinomatosis, our patient may benefit from hyperthermic intraperitoneal chemotherapy (HIPEC) in the future.

[Incidental finding of appendiceal mucinous neoplasms]. / Zufallsbefund muzinöse Neoplasie der Appendix.

Low-grade appendiceal mucinous neoplasms (LAMN) are rare and are diagnosed in at least 0.13% of appendectomies in Germany, although significant underreporting is likely. Perforation of the tumors can result in abdominal mucinous collections, so-called pseudomyxoma peritonei (PMP). The challenge in the treatment of LAMN is the adequate approach to the incidental finding of these tumors. If a mucinous neoplasm is preoperatively suspected in cases of an acute condition, usually appendicitis, it must be weighed up whether a conservative approach is justifiable or whether immediate appendectomy is necessary. If this is the case, an intraoperative perforation of the appendix must be avoided and the complete abdominal cavity must be inspected for mucin deposits. If conservative treatment is possible, further treatment should take place at a specialized center. If the neoplasm is first found incidentally during surgery, perforation of the appendix should also be avoided and the entire abdominal cavity should be inspected for a PMP. If a PMP is present cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) should be performed in a specialized center. If LAMN are found during the postoperative histological work-up, it should be evaluated whether a perforation was present and mucin collections are noted in the surgical report. In the case of LAMN without evidence of a PMP, appendectomy is the adequate treatment. In cases of intra-abdominal mucinous collections, samples should be taken and further treatment should be performed at a center with sufficient expertise. An ileocecal resection or oncological hemicolectomy is not indicated. After adequate treatment, all patients should receive a follow-up using cross-sectional imaging (preferably magnetic resonance imaging, MRI) and determination of the tumor markers CEA, CA 19-9 and CA 125.

Benign multicystic peritoneal mesothelioma mimicking mucinous ovarian neoplasm with pseudomyxoma peritonei.

Cystic mesothelioma, also known as benign multicystic peritoneal mesothelioma (BMPM), is a rare neoplasm and one of the five main histological types of peritoneal mesothelioma. Although it is usually considered benign histologically, it is increasingly accepted as a 'borderline malignancy' because the local recurrence rate is high. It is more common in middle-aged women and is generally asymptomatic. Considering that BMPM is often found in the pelvis, it is difficult to differentiate from other pelvic and abdominal lesions, such as cystic ovarian masses, especially mucinous cystadenoma-adenocarcinoma, pseudomyxoma peritonei, etc. Preoperative diagnosis is very difficult due to its rarity and lack of specific diagnostic imaging and clinical findings. Definitive diagnosis is made only by pathological evaluation. In this article, we aimed to present the imaging findings of a BMPM case in a woman who was diagnosed with mucinous ovarian neoplasm with pseudomyxoma peritonei preoperatively and underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

Appendiceal tumors and pseudomyxoma peritonei: current recommendations for clinical practice.

Appendiceal tumors and pseudomyxoma peritonei (PMP) are rare tumors. Perforated epithelial tumors of the appendix are the most common source of PMP. This disease is characterized by the presence of mucin of varying degrees of consistency, partially adherent to the surfaces. Appendiceal mucoceles themselves are also very rare and usually their treatment involves only a simple appendectomy. The aim of this study was to provide an up-to-date review of the recommendations for the diagnosis and treatment of these malignancies according to the current guidelines of The Peritoneal Surface Oncology Group International (PSOGI) and the Blue Book of the Czech Society for Oncology of the Czech Medical Association of J. E. Purkyne (COS CLS JEP).

Serum and ascites tumor markers in the diagnostic and prognostic prediction for appendiceal pseudomyxoma peritonei.

BACKGROUND: To investigate the expression of carcinoembryonic antigen (CEA), cancer antigen 199 (CA199) and CA125 in serum and ascites of appendiceal pseudomyxoma peritonei (PMP) patients relative to their diagnostic and predictive value. METHODS: The study comprised 183 patients with pathologically confirmed appendiceal PMP, enrolled from May 2012 to June 2020, in Aerospace Center Hospital. Serum and ascites tumor markers were obtained, and their diagnostic values were compared by receiver operating characteristic (ROC) curves. The prognostic factors of appendiceal PMP with different pathologic subgroups were calculated by univariate and multivariate Cox proportional hazard regression models. RESULTS: There were significant differences between the numbers of patients with positive CEA and CA199 in serum vs. ascites: p = 0.034 in CEA and p = 0.006 in CA199, respectively. The sensitivities with optimal cut-off values for ascites markers of CEA, CA199 and CA125 were 83.5%, 88.9% and 72.6%, respectively. CEA in ascites showed significant difference in the diagnosis of appendiceal PMP (p = 0.000); the areas under the ROC curves (AUROCs) and specificity were 0.725, 70.7%, respectively. Univariate analysis showed that the higher the ascites tumor markers, the poorer the survival (p = 0.014). Multivariate analysis indicated that completeness of cytoreduction (CCR), ascites CEA and pathological grade were independent risk factors for overall survival (OS). CONCLUSION: CEA in ascites can be used to help specify the origin of PMP. Furthermore, elevation of ascites CEA, high pathological grade and incomplete cytoreduction predicted poor prognosis of appendiceal PMP.

Preoperative plasma D-Dimer level is correlated with peritoneal cancer index of patients with pseudomyxoma peritonei.

PURPOSE: Accurate assessment of preoperative tumor burden contribute to formulate a scientific surgical plan for patients with pseudomyxoma peritonei (PMP). Present study aimed to assess whether the preoperative plasma D-Dimer level could reflect tumor burden for PMP patients. METHODS: A total of 253 PMP patients were included between June 1, 2013 and March 1, 2022. According to the peritoneal cancer index (PCI), all participants were divided into extensive (PCI ≥ 28) and none-extensive (PCI < 28) subgroups. The D-Dimer and tumor markers were compared between the two subgroups. The correlation between the abovementioned biomarkers and PCI will be calculated, and further compared with each other. Two-sided P value less than 0.05 is considered statistically significant. RESULTS: The level of D-Dimer (ng/ml) between extensive and none-extensive subgroup were 600 (328, 1268) vs. 339 (128, 598), Z = -5.425, p < 0.001. The Spearman correlation between D-Dimer, carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA 125), CA 19 - 9 and PCI were 0.487, 0.509, 0.469, and 0.499, respectively (all p < 0.001). The correlation coefficients were compared with each other according to Meng, Rosenthal and Rubin's method, however, there was no significant difference. CONCLUSION: Preoperative plasma D-Dimer could moderately reflect tumor burden for PMP. In the future, a multivariate prediction model will be developed to help surgeons to formulate a more precise surgical plan for the PMP patients.

[Current treatment recommendations for pseudomyxoma peritonei]. / Aktuelle Behandlungsempfehlungen beim Pseudomyxoma peritonei.

BACKGROUND: The term pseudomyxoma peritonei (PMP) describes a clinical syndrome characterized by the presence of gelatinous intraperitoneal accumulation of mucus. It mostly originates from a mucocele of the vermiform appendix. Affected patients are often asymptomatic for a long time. Because of its indolent nature it is usually diagnosed at an advanced stage. Clinical presentation is determined by the dissemination of the tumor. METHOD: A search and analysis of the current literature were carried out. RESULTS: Based on the morphological characteristics PMP subtypes with various malignant potential can be differentiated. The prognosis depends on the histopathological differentiation and the clinical stage. The treatment spectrum varies from laparoscopic appendectomy to complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). CONCLUSION: Due to the rarity of PMP there are no prospective randomized studies. Therefore, there is still controversy regarding the best stage-dependent treatment strategy. This review article attempts to clarify the optimal management of mucinous neoplasms of the appendix and PMP taking the clinical presentation and the histological differentiation into consideration.

Mucinous appendiceal neoplasms and pseudomyxoma peritonei: Morphological and clinical findings, differential diagnosis, and prognosis.

Background: Low-grade appendiceal mucinous neoplasms (LAMN) of the appendix have bland cytological features and well-differentiated morphology. Despite this, they may cause a pseudomyxoma peritonei (PMP) disease characterized by mucinous deposits in the peritoneal cavity and may exhibit malignant behavior. Aims and Objectives: In this study, we evaluated the clinical course and histopathological findings of LAMN. The rate of progression to PMP, factors affecting its development, and the clinical course of cases with PMP were investigated. Materials and Methods: Twelve thousand and forty-seven cases who underwent appendectomy were reviewed, and 71 mucinous lesions cases whose slides are in our archive were included in the study. Histopathological findings were re-evaluated. Morphological findings that guide the differential diagnosis, the clinical course of the patients, and factors affecting PMP development were determined. Results: The cases were divided into group 1 non-neoplastic (9.9%), group 2 benign (18.3%), group 3 LAMN (60.6), and group 4 malignant neoplasms (11.3%). Age, gender, appendix diameter, gross appearance, epithelial characteristics, and presence of microcalcification were significantly different between the patient groups. The presence of mucin in the ileocecal region was found to be significant in the development of PMP. It was observed that the additional procedure performed after the appendectomy did not prevent a recurrence. Conclusion: LAMNs are lesions with characteristic findings and different behaviors. The only method to distinguish from the lesions included in the differential diagnosis is to interpret the histopathological findings correctly. Additional operations after appendectomy do not contribute to preventing recurrence.

Peritoneal Pathology Review: Mullerian, Mucinous and Mesothelial Lesions.

This review provides an overview of the pathology of selected benign and malignant lesions of the female peritoneum and their often-encountered differential diagnoses. It includes endometriosis and its related lesions, endosalpingiosis, pseudomyxoma peritonei (PMP) and related ovarian/appendiceal pathology, and malignant and benign mesothelial tumors. The current terminology associated with PMP is also discussed.