Search

Appendiceal mucinous neoplasms are rare and can be associated with the development of disseminated peritoneal disease known as pseudomyxoma peritonei (PMP). Mucinous tumours identified on appendicectomy are therefore followed up to assess for recurrence and the development of PMP. In addition, individuals who initially present with PMP and are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are followed up to assess for recurrence. However, despite the concerted efforts of multiple expert groups, the optimal imaging follow-up protocol is yet to be established. The purpose of this article is to review the available evidence for imaging surveillance in these populations to identify the optimum post-resection imaging follow-up protocol., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Pseudomyxoma peritonei is an infrequent condition with a global annual incidence of only one to two cases per million people. Mucinous neoplasms, widespread intraperitoneal implants, and mucinous ascites characterize it. Currently, most clinicians misdiagnose this condition, which leads to delayed management., Case Presentation: A 44-year-old North Indian female presented with a 1.5-month history of an abdominal lump. Physical examination revealed a sizeable abdominopelvic mass at 36 weeks. Contrast-enhanced computed tomography showed a massive multiloculated right ovarian cystic mass measuring 28 × 23 × 13 cm with mild ascites and elevated carcinoembryonic antigen levels (113.75 ng/ml). A provisional diagnosis of ovarian mucinous neoplasm was made, for which the patient underwent laparotomy. Intraoperatively, there were gross mucinous ascites, along with a large, circumscribed, ruptured right ovarian tumor filled with gelatinous material. The appendicular lump was also filled with mucinous material along with the omentum, ascending colon, right lateral aspect of the rectum, splenic surface, and small bowel mesentery. Cytoreductive surgery was performed along with an oncosurgeon, including total abdominal hysterectomy with bilateral salpingoophorectomy, omentectomy, right hemicolectomy, lower anterior resection, ileo-transverse stapled anastomosis with proximal ileal loop diversion stoma, excision of multiple peritoneal gelatinous implants, and peritoneal lavage. Histopathology and immunohistochemistry confirmed the presence of intestinal-type mucinous carcinoma. Postoperatively, the patient was given six cycles of chemotherapy. She tolerated it without any specific morbidity and had an uneventful recovery. Postoperative follow-up at 15 months revealed normal tumor marker levels and abdominal computed tomography findings and no signs suggestive of local recurrence or distal metastases., Conclusions: Pseudomyxoma peritonei is a rare disease that is frequently misdiagnosed in the preoperative phase. Therefore, radiologists and clinicians should maintain a high index of suspicion for accurate diagnosis and multidisciplinary management., (© 2024. The Author(s).)

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.

Peritoneal cancer index (PCI) is the surgical variable most commonly used to quantify the extent of peritoneal metastases for pseudomyxoma peritonei (PMP) patients. The present study aimed to investigate the agreement between CT predicted and surgical PCI by the Bland-Altman method for PMP of appendiceal origin. A total of 167 PMP patients of appendiceal origin were included between 2016 and 2021. Bland-Altman analysis was performed for both total PCI and selected PCI (regions 2 + 9-12). After the Bland-Altman plot was drawn, the mean bias and its 95% limit of agreements (LoAs) was quantified. Besides, the correlation coefficients between CT-PCI and surgical PCI were also been calculated. The Bland-Altman plot showed the mean bias ± SD between total CT-PCI and surgical PCI as 0.431 ± 3.005, with the LoAs from - 5.459 to 6.321. There were nine points of difference in total PCI exceeded the 95% LoAs, with the rate of 5.39% (9/167). As for selected CT-PCI, Bland-Altman plot showed the mean bias ± SD between selected CT-PCI and surgical PCI as - 0.287 ± 1.955, with the LoAs from - 4.118 to 3.544. There were ten points of difference in selected PCI exceeded the 95% LoAs, with the rate of 5.99% (10/167). The Spearman's rank correlation coefficient between total CT-PCI and surgical PCI was 0.911, P < 0.001, as for selected CT-PCI and surgical PCI, the coefficient was 0.909, P < 0.001. Although there was a strong correlation for both total and selected CT-PCI with surgical PCI, however, the agreement is still not good in Bland-Altman analysis, which suggested that CT-PCI cannot predict surgical PCI accurately even in professional PMP treatment centers. In brief explanation, CT makes it difficult to distinguish the borderline between tumor tissue and mucus and to detect tumor lesions in the small intestine regions, which caused overestimation or underestimation by CT-PCI. In the future, a multiple linear regression model based on CT-PCI might accurately predict surgical PCI preoperatively., (© 2023. The Author(s).)

Aim: To evaluate percutaneous ultrasound-guided day-case mucin aspiration in advanced pseudomyxoma peritonei (PMP) using a wide-bore drain with regards to its safety and efficacy., Materials and Methods: All patients who underwent percutaneous mucin aspiration for PMP between 2019-2021 at a single national peritoneal tumour service were included in this study. Under local anaesthesia, a suction-enabled 28-32 F catheter was used for drainage following wire-guided track dilatation. The volume drained and difference in abdominal girth pre- and post-procedure were measured. Patients graded difficulty in breathing and abdominal discomfort pre- and post-procedure. Histology reports were reviewed., Results: Sixteen patients received 56 percutaneous mucin aspirations between 2019-2021. The aetiology was a low-grade appendiceal mucinous neoplasm (LAMN) in 50% of patients. The mean amount of mucin drained was 7,320 ± 3,000ml (range 300-13,500 ml). The mean reduction in abdominal girth post-procedure was 12.2 ± 5 cm (range 0-27 cm). Only grade 1 complications were observed., Conclusion: Percutaneous ultrasound-guided day-case aspiration of mucin for advanced and recurrent PMP using a wide-bore drain is a safe and effective procedure. It may be used in the palliative setting or as a bridge to surgery in the very symptomatic patient or if there is a reversible contraindication to surgery., (Copyright © 2023. Published by Elsevier Ltd.)

Objectives: This study aimed to identify the diagnostic accuracy of combined ultrasonography (US) and computed tomography (CT) in evaluating the tumor burden of pseudomyxoma peritonei (PMP). Besides, we assessed the ability of this combination to predict the likelihood of complete resection., Methods: This retrospective study involved 504 patients diagnosed with PMP and scheduled for cytoreduction surgery. We compared tumor burden-quantified as peritoneal cancer index (PCI) by preoperative US and CT (US-CT-PCI)-with surgical findings. Next, we assessed the prognostic value of US-CT PCI and imaging features in determining the completeness of cytoreduction (CCR) score using multivariate analysis., Results: US-CT PCI demonstrated a high PCI evaluation accuracy under moderate tumor burden. Higher US-CT PCI could predict incomplete resection. In addition, we identified imaging features such as mesenteric involvement as an independent predictor of incomplete resection (hazard ratio (HR) = 2.006; p = 0.007)., Conclusions: US-CT PCI allowed us to predict the completeness of cytoreductive surgery in patients with PMP. Moreover, the combined US and CT imaging detected several features indicating incomplete cytoreduction., Key Points: • Ultrasonography (US) can act as a complementary diagnostic modality in peritoneal cancer index (PCI) evaluation by combining CT in the small bowel area and US in the abdominal area. • A modified peritoneal cancer index (US-CT PCI) helps preoperatively evaluate tumor burden with high accuracy and allows to predict incomplete resection. • US-CT PCI of 20 or above and the involvement of particular structures such as mesentery, independently indicate incomplete resection., (© 2022. The Author(s).)

Pseudomyxoma peritonei (PMP) is a rare condition that results from the dissemination of a mucinous primary tumor and the resultant accumulation of mucin-secreting tumor cells in the peritoneal cavity. PMP can arise from various types of cancers, including appendiceal, ovarian, and colorectal, though appendiceal neoplasms are by far the most common etiology. PMP is challenging to study due to its (1) rarity, (2) limited murine models, and (3) mucinous, acellular histology. The method presented here allows real-time visualization and interrogation of these tumor types using patient-derived ex vivo organotypic slices in a preparation where the tumor microenvironment (TME) remains intact. In this protocol, we first describe the preparation of tumor slices using a vibratome and subsequent long-term culture. Second, we describe confocal imaging of tumor slices and how to monitor functional readouts of viability, calcium imaging, and local proliferation. In short, slices are loaded with imaging dyes and are placed in an imaging chamber that can be mounted onto a confocal microscope. Time-lapse videos and confocal images are used to assess the initial viability and cellular functionality. This procedure also explores translational cellular movement, and paracrine signaling interactions in the TME. Lastly, we describe a dissociation protocol for tumor slices to be used for flow cytometry analysis. Quantitative flow cytometry analysis can be used for bench-to-bedside therapeutic testing to determine changes occurring within the immune landscape and epithelial cell content.

Background: Pseudomyxoma peritonei (PMP) is a rare clinical entity, commonly derived from a mucin-producing tumour of the appendix. International consensus is unclear on the role of positron emission tomography (PET) in preoperative staging. This study aimed to assess the ability of preoperative PET in predicting the histological grade of PMP., Methods: All patients scheduled for cytoreductive surgery (CRS) +/- hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP who underwent preoperative PET at a single centre between June 2007 and June 2020 were included. A nuclear medicine physician, blinded to patient outcomes, retrospectively reviewed imaging studies to assess for maximum tumour standardised uptake value (SUV) to mean liver SUV ratio (SUV TLR ) and maximum porta hepatis SUV to mean liver SUV ratio (SUV PLR )., Results: Between April 2007 and December 2020, a total of 204 patients underwent surgical intervention for PMP. Of these, 124 (60.8%) met the inclusion criteria. Median peritoneal carcinomatosis index for the entire cohort was 9 and complete cytoreduction (CC0/1) was achieved in 109 (88%) patients. Patients with high-grade PMP were more likely to have diffuse peritoneal disease (p < 0.001) and higher SUV TLR (p<0.001). The area under the ROC curve (AUC) of SUV TLR in predicting high-grade pathology was 71% (p = 0.003). Patients with a SUV TLR ≤ 0.78 had improved disease-free survival (p = 0.042)., Conclusion: Preoperative PET showed positive correlation with high-grade PMP and acceptable sensitivity and specificity as a diagnostic tool. PET should be considered a useful adjunct to standard imaging for predicting histological grade in the staging of patients with PMP., (Copyright © 2022 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

The objective of this study was to predict the preoperative pathological grading and survival period of Pseudomyxoma peritonei (PMP) by establishing models, including a radiomics model with greater omental caking as the imaging observation index, a clinical model including clinical indexes, and a combined model of these two. A total of 88 PMP patients were selected. Clinical data of patients, including age, sex, preoperative serum tumor markers [CEA, CA125, and CA199], survival time, and preoperative computed tomography (CT) images were analyzed. Three models (clinical model, radiomics model and combined model) were used to predict PMP pathological grading. The models' diagnostic efficiency was compared and analyzed by building the receiver operating characteristic (ROC) curve. Simultaneously, the impact of PMP's different pathological grades was evaluated. The results showed that the radiomics model based on the CT's greater omental caking, an area under the ROC curve ([AUC] = 0.878), and the combined model (AUC = 0.899) had diagnostic power for determining PMP pathological grading. The imaging radiomics model based on CT greater omental caking can be used to predict PMP pathological grading, which is important in the treatment selection method and prognosis assessment., (© 2022. The Author(s).)

The peritoneum is a unique serosal membrane, which can be the site of primary tumors and, more commonly, secondary pathologic processes. Peritoneal carcinomatosis is the most common malignant condition to affect the peritoneal cavity, and the radiologist plays an important role in making the diagnosis and assessing the extent of disease, especially in sites that may hinder surgery. In this review, we address the role of the radiologist in the setting of peritoneal pathology, focusing on peritoneal carcinomatosis as this is the predominant malignant process, followed by revising typical imaging findings that can guide the differential diagnosis.We review the most frequent primary and secondary peritoneal tumor and tumor-like lesions, proposing a systemic approach based on clinical history and morphological appearance, namely distinguishing predominantly cystic from solid lesions, both solitary and multiple.

Aim: Pleural dissemination of pseudomyxoma peritonei (PMP) is an extremely rare diagnosis, for which no standard therapy is available. Methods: We describe the successful treatment of a 67-year-old male diagnosed with left-sided intrapleural dissemination of PMP (low-grade appendiceal mucinous neoplasm), 2 years after treatment of abdominal PMP with cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy. Treatment consisted of extended pleural decortication (ePD) and oxaliplatin-based hyperthermic intrathoracic chemotherapy (HITHOC). The patient is doing well without complications or signs of recurrence, 26 months after thoracic surgery. Conclusion: ePD in combination with HITHOC is a valuable treatment for thoracic PMP.

A 53-year-old lady presented with post-menopausal bleeding (spotting) for two days and abdominal pain for three months. CT scan revealed bilateral adnexal mass and ascites; and CEA and CA19.9 was raised. Histopathology of the resected tissues revealed mucinous carcinoma of bilateral ovaries and colon with omental metastasis. Generally, pseudomyxoma peritonei arises from primary ovarian or appendiceal adenomas or adenocarcinomas. Keywords: Adenocarcinomas; ascites; metastases; mucinous carcinoma; pseudomyxoma peritonei.

History A 57-year-old man with no remarkable past medical history presented to an outside institution with painless swelling in his right thigh of 6 months duration. He denied any trauma to the site. At that time, physical examination demonstrated swelling in his right upper thigh. All other work-up, including complete blood count and chest radiography, yielded negative results. The initial diagnosis was lymphangioma of the thigh. He continued to experience worsening swelling in his right upper thigh with no other symptoms over the next year. He was referred to our facility, where he underwent US evaluation of the thigh lesion, an MRI scan encompassing the entire extent of his thigh lesion, and a CT scan of his abdomen and pelvis.

Peritoneal pseudomyxoma (PP) is a rare malignant tumor, which is characterized by the presence of mucinous ascites. Abdominal ultrasound as the first diagnostic method of this entity allows the visualization of ascites on the one hand and its analysis through a diagnostic paracentesis on the other.

Objective: To explore the clinicopathologic features and prognosis of female appendiceal mucinous tumor misdiagnosed as gynecological neoplasm. Methods: The clinical data of 12 cases of suspected gynecological neoplasm but confirmed as appendiceal mucinous tumor by operation and pathology in Beijing Obstetrics and Gynecology Hospital hospital from 2010 to 2019 were collected. The clinicopathologic features, treatment and prognosis of these patients were analyzed. Results: The median age of 12 patients was 58 years old and the clinical manifestations were atypical, including 5 cases with gastrointestinal symptoms, 6 cases with touched lesion in the right adnexal area, 3 cases with pseudomyxoma of peritonei, and 4 cases with increased serological tumor markers and ascites. Before operation, ultrasonic diagnosis showed cystic or cystic-solid mass in the right adnexal region in all cases. Pelvic and abdominal enhanced CT and/or enhanced MRI were performed in 5 cases. Two cases indicated possible origin of appendix and 1 case indicated lymphatic cystic tumor. Laparoscopic or laparotomy exploration was performed in all patients, during the operation 7 cases were performed appendectomy, 4 cases were performed tumor cell reduction and 1 case was treated in another hospital after laparotomy exploration. Eleven cases were diagnosed as low-grade appendiceal mucinous tumor and 1 case as appendiceal mucinous adenocarcinoma by postoperative pathology. Among the 11 patients with low-grade appendiceal mucinous tumor, 9 cases had no recurrence, 1 case lost follow-up, 1 case died of breast cancer and 1 case died 18 months after the operation. Conclusions: Gynecologists should improve their ability to differentiate appendiceal mucinous tumor from gynecological neoplasm. They can include ultrasonic diagnosis and CT scanning into their preoperative physical examination to improve their examination ability, and strive for specialist or surgical treatment to achieve the best result.

MR imaging provides considerable advantages in the evaluation of patients with peritoneal metastases. A standardized peritoneal MRI protocol, including diffusion-weighted and gadolinium-enhanced sequences, allows an efficient exploration of small peritoneal tumors that are often missed on other imaging tests. In experienced hands, a dedicated reading allows producing a quantitative and qualitative evaluation of lesional localization to better assist surgeons in the selection of candidates for curative surgery by evaluating the possibility of complete resection, and to plan the surgical procedure. Based on a close collaboration between oncologic surgeon and radiologist, MRI provides a powerful tool for accurate preoperative imaging in patients being considered for curative surgery but also in their surveillance to detect an early recurrence., (Copyright © 2019 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Objectives: Pseudomyxoma peritonei (PMP) is characterized by peritoneal dissemination of gelatinous ascites following rupture of a mucinous tumor. Treatment by cytoreductive surgery (CRS) has improved its prognosis. Although visceral scalloping, notably liver scalloping, on computed tomography (CT) is a typical feature of PMP, its prognostic value remains unknown. We aimed to investigate the efficacy of liver scalloping in predicting recurrence in PMP patients., Methods: Among 159 consecutive patients with PMP who had contrast-enhanced CT between September 2012 and December 2018, 64 treatment-naïve patients who subsequently underwent CRS with complete resection (i.e., completeness of cytoreduction score (CC)-0 or CC-1), were included in analysis. Presence of liver scalloping and maximum thickness of mucin deposition at the liver surface were evaluated on CT. Disease-free survival (DFS) was determined based on the combination of postoperative CT features and tumor marker values., Results: Median follow-up was 24.3 months. CT revealed liver scalloping in 40/64 (63.4%) patients. Kaplan-Meier analysis showed significantly shorter DFS in patients with scalloping than in those without (p = 0.001; hazard ratio, 4.3). In patients with scalloping, greater mucin deposition (thickness ≥ 20 mm) significantly correlated with poorer DFS (p = 0.042). In multivariate Cox proportional hazards regression including CC status, pathologic type, and tumor markers, the presence of scalloping independently and significantly correlated with DFS (p = 0.031)., Conclusions: Liver scalloping was an independent predictor even after adjusting for clinical covariates. The presence of liver scalloping can lead to a high recurrence rate after CRS., Key Points: • The presence of liver scalloping is a prognostic factor independent of histological grade and tumor markers. • Greater mucin deposition (thickness ≥ 20 mm at the liver surface) is associated with higher recurrence rates in patients with liver scalloping.

Mucinous cystadenoma are rare benign mucin-producing tumours. Primary mucinous neoplasms most commonly involve ovary, pancreas or appendix. They may rupture to produce mucous ascites/pseudomyxoma peritonei. We are describing a 51-year-old man who presented to us with symptomatic gallstone disease but during preoperative ultrasound was found to have cystic lesions in spleen with free fluid in the abdomen. Splenectomy and drainage of mucin were done. Histopathology was done and a final diagnosis of primary mucinous cystadenoma of spleen with mucinous ascites was made., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: This study aimed to explore the value of preoperative ultrasonography (US) in evaluating the peritoneal cancer index (PCI) of pseudomyxoma peritonei (PMP)., Methods: An ultrasound examination was performed on 59 patients with PMP before surgery, and the ultrasound PCI was evaluated. The accuracy of ultrasound PCI score was evaluated with the surgical PCI score as the gold standard., Results: The preoperative ultrasound PCI was compared with the surgical PCI. The Spearman correlation coefficient of the total PCI score was 0.608 (P < 0.05). The difference in the Spearman correlation coefficient between the preoperative ultrasound PCI and the surgical PCI in areas 0-7 was statistically significant. (1) Among them, the total score and the correlation between 0-3 and 6 were higher. (2) Compared with the surgical PCI, overestimation (> 20%) was concentrated mainly in areas 2 and 4-8 for 2 points, and underestimation (< 20%) was concentrated mainly in areas 1, 3, 4, and 8 for 3 points. (3) The sensitivity and specificity of preoperative ultrasound for predicting the presence or absence of lesions were 85.7% and 50.0%, respectively. The sensitivity of LS 1, LS 2, and LS 3 was 31.7%, 48.2%, and 71.0%, respectively, and the specificity was 44.8%, 55.3%, and 58.8%, respectively., Conclusion: The ultrasound examination can be used to score the preoperative PCI, judge the severity, and predict the prognosis in patients with PMP.

Recent advances, specifically cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), offer advantages compared to the traditional therapeutic approach of systemic chemotherapy in the treatment of peritoneal carcinomatosis from mucinous appendiceal neoplasms (MAN). This review provides an up-to-date, comprehensive summary of the histologic classification of MAN, reviews common imaging findings of mucoceles and pseudomyxoma peritonei, and describes the radiologist's role in the multidisciplinary care team in quantifying disease and in helping select patients for definitive surgery.

Pseudomyxoma peritonei is a rare tumor characterized by the presence of mucous disseminated throughout the peritoneal cavity generally arising from the rupture of an appendicular mucocele. Liver scalloping is a highly suggestive image of pseudomyxoma and corresponds to the indentation of the liver compressed by the gelatinous mucin., (Copyright © 2018. Published by Elsevier Masson SAS.)

Introduction: Ascites in patients with cardiac disease can be multifactorial. Serum ascitic albumin gradient (SAAG) helps in identifying the etiology of ascites. High SAAG ascites is related to hepatic or posthepatic causes. The causes of low SAAG ascites results include tuberculosis, peritoneal malignancy, or pancreatitis., Case Presentation: We report an unusual cause of low SAAG ascites in a 48-year-old woman with valvular heart disease. The patient presented with ascites, and cross-sectional imaging revealed a right iliac fossa mass with omental deposits. The patient was finally diagnosed as having pseudomyxoma peritonei on the basis of clinicoradiopathological features., Discussion: Pseudomyxoma peritonei is a rare cause of low SAAG ascites. It is characterized by the deposition of mucinous material on the peritoneal surfaces. The most common site of origin is the appendix, although it can arise from other intraabdominal organs as well. Excision of the tumor combined with intraperitoneal chemotherapy is the preferred modality of treatment.

Background: Curative treatment of pseudomyxoma peritonei (PMP) is complete cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC)., Objective: The aim of this study was to build and evaluate a preoperative imaging score to predict resectability., Patients and Methods: Between 2007 and 2014, all PMP patients in two tertiary reference centers who underwent laparotomy with intent to undergo CRS and HIPEC were included in this study retrospectively. Thickness of tumor burden was measured on preoperative multidetector-row computed tomography (MDCT) by two radiologists blinded to surgical results in five predetermined areas. Patients were divided into two cohorts with the same resectability rate (building and validation). The performances of the scores were assessed using receiver operating characteristic (ROC) curve analyses., Results: Overall, 126 patients were included, with compete CRS being achieved in 91/126 patients (72.2%). Two cohorts of 63 patients matched by age, sex, burden of disease, resectability rate, and pathological grade were constituted. The MDCT score was the sum of the five measures, and was higher in unresectable disease [median 46.2 mm (range 27.9-74.6) vs. 0.0 mm (range 0.0-14.0), p < 0.001]. Area under the ROC curve was 0.863 (range 0.727-0.968) and 0.801 (range 0.676-0.914) in the building and validation cohorts, respectively. A threshold of 28 mm yielded a sensitivity, specificity, positive predictive and negative predictive value of 94, 81, 81 and 94% in the building cohort, and 80, 68, 59 and 85% in the validation cohort, respectively. Using our score, overall and disease-free survival were increased in the group classified as resectable., Conclusion: A simple preoperative MDCT score measuring tumor burden in the perihepatic region is able to predict resectability and survival of PMP patients.

Introduction: Pseudomyxoma peritonei (PMP) is a rare clinical condition, with an incidence of 1-2 cases per million, characterized by the dissemination of mucinous implants on the peritoneal surface and progressive gelatinous ascites. Although it usually presents an indolent behavior, its non-specific clinical presentation contributes to many cases remaining undiagnosed until a laparotomy is performed. With late diagnosis, performed after a long period of clinical deterioration and disease progression, it is common to find complications such as the formation of intestinal fistulas and obstruction., Method: Review of the medical record and search for references in the Medline, Lilacs, SciELO and MD Consult databases., Results: There are rare case reports found in the literature demonstrating atypical PMP presentations. Our report is that of a 17-year-old adolescent with a sporadic tumor diagnosed in a primary site in the transverse colon, contrary to data commonly found in the literature that mention a more frequent occurrence in women in the fifth decade of life and with a primary site in the ovary and appendix. The development of mucinous adenocarcinoma is rare in the pediatric population, and topography in the transverse colon and non-familial sporadic pattern are unusual., Conclusion: The case reported not only raises awareness about the atypical presentations of the disease, but also emphasizes the use of imaging examinations for diagnosis, which has an important impact on prognosis and survival if performed timely.

Rationale: Pseudomyxoma peritonei is an unusual clinical condition, and the appendix and ovaries are reported as the primary sites., Patient Concerns: A 44-year-old man who was reported a 3-month history of lower abdominal pain and distention, along with increased abdominal girth, was admitted with a palpable tender mass in the central lower abdomen., Diagnosis: Ultrasonography showed a large well-circumscribed cystic-solid mass with lobulated margin, extending from the anterosuperior dome of the urinary bladder to the anterior abdominal wall. A computed tomography (CT) scan revealed a midline heterogeneous, hypodense, irregular polycystic-solid mass adjacent to the anterior wall of the abdomen and anterior to the dome of the urinary bladder. fluorodeoxyglucose positron-emission tomography/CT showed intense fluorodeoxyglucose uptake in the thickened wall of the mass. Intraperitoneal laparoscopic exploration also revealed a midline abdominal mass adjacent to the dome of the urinary bladder. Laparotomy showed that the mass originated from the dome of the urinary bladder and was disconnected with the urinary bladder lumen. The final histopathological diagnosis was urachal mucinous adenocarcinoma associated with high-grade pseudomyxoma peritonei., Interventions: The patient underwent surgical cytoreductive procedure and the perioperative intraperitoneal chemotherapy., Outcomes: The patient made an uneventful recovery, and 7 months later had no recurrence., Lessons: The urachus is a tubular structure, which extends medially from the apex of the bladder to the allantoid during fetal development, and it usually obliterates after birth. Urachal remnants can cause urachal carcinoma or bladder cancers. Pseudomyxoma peritonei originating from mucinous neoplasm of the urachus is extremely rare.

Background: Low-grade appendiceal mucinous neoplasms are rare. Both classification and management vary. This study aimed to follow up on patients with a diagnosis of LAMN after primary surgery with computer tomography (CT) scans to examine the risk for the development of pseudomyxoma peritonei (PMP)., Methods: This population-based prospective study investigated patients who underwent appendectomy between 2007 and 2013 and had histology results demonstrating the presence of LAMN. The patients were followed up with a CT scan every 6 months for 2 years, until December 2015., Results: The study investigated 41 patients (20 females) with a median age of 65 years (range 20-87 years). The entire appendix was processed and examined, with results showing that 12 were perforated, and 3 had a positive margin. Extra-appendiceal mucin on the surface of the appendix was found in ten cases, and in two cases, extra-mucinous epithelial cells were detected. During a median follow-up period of 5.1 years (range 2-8.6 years), none of the patients experienced the development of PMP., Conclusions: These data suggest that for patients with LAMN confined to the appendix, involvement of the appendectomy margin or perforation with mucin locally, even with epithelial cells, did not predict the development of PMP, and a conservative approach seems justified. No reoperation was needed, and regular follow-up evaluation with CT scans was sufficient.

Background: Pseudomyxoma peritonei is a disease that results from a perforated mucinous neoplasm of the appendix so that mucinous ascites and mucin-producing tumor cells are widely disseminated in a characteristic pattern throughout the abdomen and pelvis. The intraabdominal mucus can accumulate in the inguinal canal and by physical examination be indistinguishable from the usual inguinal hernia., Methods: A database of patients with pseudomyxoma peritonei was used to identify patients who had an inguinal hernia prior to or at the time of cytoreductive surgery (CRS) and perioperative hyperthermic chemotherapy (HIPEC). At the time of CRS, care was taken in all patients to remove the peritoneal lining of the inguinal canal. Patients who had the inguinal hernia repaired prior to definitive treatment with CRS and HIPEC had all tissue and mesh associated with prior herniorrhaphy resected., Results: In 178 pseudomyxoma peritonei patients, 17 had a new onset or previously repaired inguinal hernia that required extraction of mucus and mucinous tumor from the hernia site. No repair of the open inguinal canal was attempted at the time of CRS. No recurrent inguinal hernias were recorded and no patients required an inguinal incision at a later time to resect progressive disease within the inguinal canal., Conclusions: Inguinal hernias caused by mucinous ascites and tumor were definitively treated by cytoreductive surgery plus HIPEC. Extraction of tumor and peritoneum from the inguinal canal facilitates fibrous closure of the hernia defect so that hernia recurrence was not observed., (Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Cancer imaging on the peritoneum is quite difficult on PET/CT because of the particular anatomical features of this membrane. The abdominal cavity can be the seat of very different primary or secondary tumoral lesions, with heterogeneous aggressiveness and variable fluorine-18 fluorodeoxyglucose uptake and patterns. We aimed to depict a spectrum of appearances with abnormal fluorine-18 fluorodeoxyglucose uptakes localized on the peritoneum in frequent conditions such as peritoneal carcinomatosis and in rarer disease such as desmoplastic round cell tumor.

Purpose: Pseudomyxoma peritonei (PMP) is a rare peritoneal neoplasm originating from appendicular tumours. There is no consolidated data available in the literature about the precise role of [(18)F] fluorodesoxy-D-glucose Positron Emission Tomography / contrast enhanced Computed Tomography (FDG-PET/ceCT). The aim of this study was to evaluate the correlation between preoperative FDG-PET/ceCT (qualitative and semi-quantitative assessment) and progression free survival (PFS) of patients treated for PMP., Methods: All patients scheduled for PMP treatment by cytoreductive unicentric surgery, intraperitoneal chemotherapy (HIPEC), and who underwent a FDG-PET/ceCT between February 2008 and January 2014, were included. No previous treatment was performed (except biopsy or appendectomy). FDG-PET/ceCT was interpreted by two nuclear physicians in consensus. Positive FDG-PET/ceCT scans were further labelled in diffuse disease and poly/mono focal disease. SUVmax was measured based on post-operative reports. The Peritoneal Cancer Index (PCI) and Completeness of CytoReduction Score (CCR) were assessed after surgery., Results: Fifty-six patients were included in this study, with a mean age of 56-years-old and a mean follow-up of 29.3 months. SUVmax, with a cut-off at 2.02, was predictive for the PFS on multivariate analysis. No differences were observed between diffuse disease and focal disease on PFS for progression free survival, PCI, and SUVmax (p = 0.1). Post-operative CCR was not significantly correlated with SUVmax or FDG-PET/ceCT qualitative assessment., Conclusion: SUVmax on preoperative FDG-PET/ceCT was an independent predictive factor for PFS in PMP. Further studies are needed to explore if FDG-PET/ceCT could potentially predict post-operative CCR.

Pseudomyxoma peritonei (PMP) is a rare disease, caused by primary mucinous tumors that arise most frequently from appendix, ovary, or pancreas. Usually diagnosis is made by computed tomography, but ultrasonography can be a very useful imagistic method, if this diagnosis is taken into account by the observer. We present a case of a PMP caused by an appendiceal mucinous carcinoma, in a 34-year-old male patient, with family history of malignancies, diagnosed in our department. He was thereafter surgically treated - appendiceal resection, peritoneal lavage - followed by chemotherapy. We underline the importance of ultrasonography, even though at first encounter, the diagnosis of PMP being generally difficult.

Pseudomyxoma retroperitonei is a rare condition, characterized by accumulation of mucinous material in the retroperitoneal space, originating predominantly from the appendiceal mucinous neoplasms. A72-year-old male patient presented with a history of progressive right side abdominal pain for 5 months with a palpable abdominal mass. Ultrasound, computerized tomography, and magnetic resonance imaging showed large right abdominal multiloculated cystic lesion with heterogeneous echoic contents. Colonoscopy revealed normal mucosa with extramural pressure on the right colon and cecum. He underwent complete excision of the mass along with right hemicolectomy. The cystic mass was containing gelatinous material. Histopathology revealed low grade mucinous neoplasm. Pseudomyxoma retroperitonei should be considered in the differential diagnosis of patient presenting with progressive right side abdominal pain and retroperitoneal cystic mass.

Introduction: Pseudomyxoma peritonei (PMP) and peritoneal carcinomatosis (PC) arises from primary or secondary peritoneal cancer and can be treated with complete surgical removal of disease. Suitability for surgery is based on a peritoneal cancer index (PCI), with a PCI ≥ 20 representing unresectable disease., Aims: Compare preoperative imaging with surgical findings based on PCI., Methods: All cases of patients with PMP and PC undergoing cytoreductive surgery ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 2010 and 2014 were included. Two staff radiologists blinded to surgical PCI scores retrospectively reviewed imaging studies to calculate corresponding radiologic PCI scores for each patient. Correlation between radiologic PCI and surgical PCI, as obtained from operative reports, was assessed using Spearman's rho correlation coefficients. Preoperative assessment of a PCI cutoff of 20 on imaging was compared with actual surgical PCI using sensitivity, specificity, and positive and negative predictive values., Results: Forty-two patients had a mean surgical PCI ± SEM score of 15.1 ± 1.3 and mean radiologic PCI of 15.5 ± 1.5. The most common tumor histologies were appendiceal (60 %) and colon (33 %) adenocarcinoma and were of low tumor grade (67 %). Correlation between individual radiologists and surgical PCI was 0.59 and 0.62, respectively (all p < 0.001). When mean radiologic PCI was used, this correlation with surgical PCI improved to 0.64 and to 0.65 when good quality studies only were considered (all p < 0.001). Radiologic PCI score had a sensitivity of 76 %, a specificity of 69 %, positive predictive value of 85 %, and a negative predictive value of 56 % when compared with the surgical PCI. In patients with a radiologic PCI score ≥ 20, 6/13 (46 %) still achieved adequate cytoreduction., Conclusions: Good quality cross-sectional imaging, combined with overreading and formal assessment of all components of the PCI score yields the best correlation with actual surgical findings. Although preoperative assessment of PCI ≥ 20 was reasonably accurate, using this cutoff to assess resectability is problematic as almost half of these patients were still able to undergo adequate cytoreduction. Better assessment of resectability is needed preop, either by refinement of the PCI criteria or routine staging laparoscopy.

Background: Complete cytoreduction with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has been shown to improve survival in patients with low-grade mucinous adenocarcinoma (LGMA). However, incomplete cytoreduction exposes patients to significant morbidity without a similar survival benefit. Preoperative assessment of the ability to achieve CRS is therefore a critical step in selecting patients for CRS/HIPEC., Objective: The aim of this study was to develop and validate a preoperative scoring system to accurately predict the ability to achieve complete cytoreduction in patients with LGMA of the appendix., Methods: A simplified preoperative assessment for appendix tumor (SPAAT) score was developed based on computed tomography scan findings thought to predict incomplete cytoreduction. We applied the SPAAT score to patients with LGMA to determine the ability of the score to predict complete cytoreduction. This scoring system was then applied to a separate cohort of patients from a different institution. Sensitivity and specificity were determined for the SPAAT score. Survival was calculated and correlated with the SPAAT score and the completeness of cytoreduction score., Results: A SPAAT score of <3 is a significant predictor of complete cytoreduction in the derivation cohort. In the validation cohort, 40 of 42 patients with a SPAAT score <3 achieved a complete cytoreduction, for a positive predictive value of 95.2 % and a negative predictive value of 100 %. Additionally, the SPAAT score was a significant predictor of disease-free survival., Conclusions: The SPAAT score is a useful tool in the preoperative assessment of patients with LGMA who are under consideration for cytoreductive surgery. Prospective analysis of this scoring system is warranted to appropriately select patients who will benefit from CRS/HIPEC.

A 42-year-old man with diabetes and hypertension presented to the emergency room after experiencing a several month history of gradually increasing abdominal girth with the sudden onset of abdominal pain.

Objective: To investigate the value of ultrasound in the diagnosis of pseudomyxoma peritonei (PMP) and summarize the ultrasonographic features of PMP by comparing with computed tomography (CT) findings., Method: Ultrasound and CT scan results of 25 patients with PMP confirmed by pathology after surgery were analyzed retrospectively., Results: Among these 25 PMP patients,three were diagnosed by ultrasound and six by CT(P=0.579). The specific ultrasonographic features of PMP were as follows:the dense punctuate echoes or floccules were detected in hydrops abdominis,which seldom or never move with the change of body position. Honeycomb-like lesions were typical. Notches were formed on the surface of liver or spleen due to the mucinous material and/or the mucinous lesions., Conclusions: Both ultrasound and CT scan have poor detection rate in the diagnosis of PMP. PMP has specific ultrasonographic features,which may make it possible to diagnose most PMP lesions by ultrasound before surgery

Objectives: The purpose of this study was to analyze the sonographic features of pseudomyxoma peritonei and the ability of preoperative sonography to assess the pathologic grades of this disease., Methods: Nineteen patients with pseudomyxoma peritonei who underwent preoperative sonographic examinations were included (9 male and 10 female; age range, 31-70 years). Four patients presented with disseminated peritoneal adenomucinosis, 7 with peritoneal mucinous carcinomatosis with intermediate or discordant features (intermediate-grade disease), and 8 with peritoneal mucinous carcinomatosis. The sonographic characteristics, clinical features, and serum tumor marker levels were recorded and compared among the 3 grades., Results: Clinical symptoms and carcinoembryonic antigen, cancer antigen 125 (CA-125), CA-19-9, CA-724, and CA-153 levels were not significantly different among the 3 pathologic grades (P > .05). Ascites, scalloping of the visceral margin, invasive parenchymal nodules, and peritoneal masses were detected in all grades. Disseminated peritoneal adenomucinosis occurred without the finding of an omental cake. The presence of enlarged lymph nodes was more common in peritoneal mucinous carcinomatosis. The diagnosis of pseudomyxoma peritonei was made by preoperative sonography in 1 case. Four cases were diagnosed as ovarian mucinous cystadenoma with rupture. One case was diagnosed as a mucinous appendiceal cyst. Four cases were diagnosed as ascites or encapsulated effusion. One case was misdiagnosed as lymphoma. The others were diagnosed as celiac masses., Conclusions: Preoperative sonography can be used to diagnose pseudomyxoma peritonei as long as radiologists are familiar with the imaging features. Although there are overlaps in the sonographic findings among the different grades, some features may aid in separating them.

Objectives: The purpose of our study was to assess the sonographic features of pseudomyxoma peritonei (PMP)., Materials and Methods: All records of peritoneal biopsies under the guidance of ultrasound in our institutional database from April 2007 to June 2011 were retrospectively reviewed. 19 cases of PMP and 279 cases of other peritoneal lesions were included in the study. The sonograms of peritoneum, ascites, and parenchymal organs involved by PMP were evaluated, respectively, and compared with sonograms of other peritoneal lesions., Results: Anechoic areas were found in 89.5% cases of PMP at high frequency of insonation and the sensitivity in indicating PMP was 100%. In the pelvic cavity, echogenic foci in ascites of PMP in 52.6% cases were mobile. The specificity of "starburst" appearance and sensitivity of scalloping of the liver margin were relatively high (82.3 and 88.1%), but the sensitivity and specificity (57.9 and 42.1%) of these two signs were relatively low., Conclusion: Anechoic area in the thickened peritoneum was a specific sign in indicating the diagnosis of PMP and high-frequency transducer could reveal these tiny anechoic areas more explicitly. In the pelvic cavity, echogenic foci in ascites of PMP could be observed to be mobile and scalloping of the liver margin and "starburst" appearance also played a significant role in indicating PMP.

Background: Delayed repeated intraperitoneal chemotherapy after cytoreductive surgery for carcinomatosis may be an alternative to intraoperative hyperthermic infusion., Objective: The aim of this study was to evaluate the safety and feasibility of delayed repeated intraperitoneal chemotherapy after cytoreduction of colorectal and appendiceal carcinomatosis and pseudomyxoma peritonei., Design: This study constitutes a retrospective case series., Setting: This study was conducted at a single institution., Patients: A total of 31 patients with peritoneal carcinomatosis (23) and pseudomyxoma peritonei (8) were included., Interventions: Cytoreduction was followed by placement of an adhesion barrier and intraperitoneal catheters. Peritoneal scintigraphy preceded biweekly intraperitoneal 5-fluorouracil and systemic combination chemotherapy with leucovorin, fluorouracil, and oxaliplatin (FOLFOX)., Main Outcome Measures: The primary outcomes measured are safety, feasibility, and short-term survival., Results: Cytoreduction to a score of 0 to 1 was possible in 25 patients (80%). Complications occurred in 16 patients (51.6%) and were confined to grades I to III. There were no deaths, and no digestive fistulae occurred. Port malfunction or complication resulted in removal in 5 patients (16.1%). Intraperitoneal chemotherapy was possible in 83.8% of patients; 55% completed the full course. Peritoneal scintigraphy demonstrated free diffusion of tracer in 18 patients (58%), 4 (12.9%) had diffusion in each gutter with limited communication, 5 (16.1%) had limited diffusion around each catheter without communication, and 2 (6.5%) had no diffusion on scintigraphy. Overall survival for peritoneal carcinomatosis was 44.5% at 3 years (95% CI = 23%-65%)., Limitations: The nonrandomized nature of this study and the early experience are limitations., Conclusions: Delayed repeated intraperitoneal and systemic chemotherapy after cytoreduction is feasible and has acceptable morbidity rates. Delayed intraperitoneal chemotherapy is possible in 83% of patients.

Pseudomyxoma peritonei (PMP) is a disease with various clinical presentations and the diagnostic value of ultrasonography (US) is under investigated. The purpose of this study was to identify the most common US finding in PMP and to investigate US sensitivity, specificity, positive and negative predictive value in quantifying tumour burden in different abdomino-pelvic regions in PMP patients. Between February 2006 and December 2008, 54 patients were treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) due to PMP. The results from preoperative US examination with and without intravenously administrated contrast (SonoVue) were compared to surgical findings. The mean US peritoneal cancer index (PCI) was 6 (range 0-25) and the surgical PCI was 18 (range 3-27) p<0.0001. The histo-pathological subtypes did not influence the US findings. Ascites, bowel loops adhesions and omental cake were mostly visualised correctly by US. The sensitivity of US in quantification of tumour nodules was 91.5% (range 74-100%) and specificity was 33.8% (range 18-55%). The positive predictive value of US examination in PMP was 22% (range 11-44%) and the negative predictive value was 93% (range 77-100%). US can detect the most common PMP findings (ascites and omental cake). The sensitivity of US to quantify PMP tumour burden in different abdominio-pelvic region was relatively high, however, this imaging tool had low specificity., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Introduction: Pseudomyxoma Peritonei (PMP) is a rare condition, which arises from the abdominal cavity and it may also involve the pleural cavity occasionally. Concomitant involvement of both cavities is rare. The disease is characterized by production of mucinous ascites, and a low-grade carcinoma deriving mostly from the appendix. Pleural seeding may be due to diaphragmatic perforation during surgical intervention, tumour progression, or persistent congenital malformation between the abdominal and pleural cavities., Case Report: A 44 year-old female patient was treated with pleuropulmonary involvement of pseudomyxoma. Since both the lungs and pleura were involved, radical resection could not have been carried out, and cytoreduction with intraoperative chemotherapy was applied only., Discussion: Pleural progression of pseudomyxoma is uncommon and carries a poor prognosis. Management is similar to abdominal PMP, which involves aggressive cytoreduction and local and/or systemic chemotherapy, if possible., Conclusion: PMP is a very uncommon disease with poor prognosis. Extra-abdominal manifestation is rare, too. However, early recognition of the condition may enhance treatment options.

Pulmonary giant cell carcinoma is a rare subtype of sarcomatoid carcinoma. Pseudomyxoma peritonei (PMP) is a rare condition in which gelatinous material accumulates within the peritoneal cavity. It is believed PMP arises from a primary appendiceal mucinous neoplasm that perforates the gut, causing mucinous ascites. There are sporadic reports of PMP associated with neoplasms of other organs, rarely the lung. Here, we report on a 60-year-old woman with pulmonary giant cell carcinoma associated with PMP. She presented with progressive dyspnea and abdominal distention. Abdominal computed tomography revealed moderately dense ascites without an obvious mass. Chest computed tomography revealed a large, solitary right lower-lobe lung mass. She underwent transbronchial fine-needle aspiration of the mass, and was diagnosed with pulmonary giant cell carcinoma. The ascites showed scattered malignant cells in a background of mucin, confirming PMP. To our knowledge, this is the first report of pulmonary giant cell carcinoma associated with PMP.