Malignant transformation of "benign" cystic mesothelioma of the peritoneum

Benign multicystic peritoneal mesothelioma in a sexagenerian man: an uncommon case presentation

BACKGROUND

Multicystic mesothelial cyst is a rare, and usually benign, tumor which is rarely diagnosed preoperatively due to the poor specificity of its symptomatology.

METHODS

We report the case of a 63-year-old man with multiple comorbidities (e.g. cryptogenic cirrhosis, chronic heart failure) and a history of surgical resection of a giant abdominal cyst, who complained of recurrent intermittent abdominal pain and vomiting that appeared several weeks before. Abdominal computed tomodensitometry (CT) revealed multiple diffusely localized cysts in the abdominal cavity, ranging from 30 mm to 210 mm.

RESULTS

The patient underwent surgical resection of twelve intra-abdominal cysts, identified at final pathology as benign mesothelial cysts, which were probably a recurrence following the previous surgery for a single intra-abdominal cyst. Three months later, the patient recurred with development of two new intraperitoneal cysts, with an increasing volume on CT at last follow-up (18 months). Surveillance was recommended given the patient's comorbidities and the absence of symptoms.

CONCLUSIONS

Surgical resection is the treatment of choice for multicystic peritoneal mesothelioma, a rare disease that should be considered more as a borderline tumor than a benign tumor, given the high risk of recurrence and possible malignant transformation.

Large and Extensive Multilocular Peritoneal Inclusion Cysts Lack Genomic Alterations and Follow an Indolent Clinical Course Despite Rare Recurrences

Peritoneal inclusion cysts (PICs) are unilocular or multilocular cystic lesions lined by bland mesothelial cells. While most are small and localized, rare examples may be large or multifocal with diffuse peritoneal involvement, causing clinical and even pathologic concern for malignancy. We examined 20 PIC, including 8 large solitary and 12 multifocal lesions. Solitary PIC were found in 7 female and 1 male patients ranging from 19 to 55 (median: 37) years. Expanded collagenous (n=2) or edematous (n=1) areas were occasionally seen in the septae, and 1 had microscopic foci of myxoid stroma. Four had hobnail cells, and 1 had minor areas of papillary mesothelial hyperplasia. Multifocal PICs occurred in 9 female and 3 male patients ranging from 26 to 80 (median: 53) years. Three showed extensive associated fibrosis with entrapment of preexisting adipose tissue, 2 had areas resembling granulation tissue, and 3 had scattered foci of myxoid stroma. Hobnail cells were present in 9, papillary mesothelial hyperplasia in 2, entrapped single cells in 1, and 2 had areas resembling adenomatoid tumors. Two of the multifocal PICs had limited local recurrences at 18 and 21 months. No patients died of disease. Clonal alterations were not identified in any of the tested PICs (mutational and fusion analysis in 5, chromosomal microarray in 1). Despite limited local recurrences, we demonstrate that even large and multifocal PICs may lack identifiable genomic alterations and are associated with benign outcomes.

Uterine mesothelial cysts mimicking ovarian cysts in a primipara patient with a history of Cesarean section: A case report and review of the literature

OBJECTIVE

We describe a rare case of uterine mesothelial cysts mimicking ovarian cysts in a primipara patient with a history of Cesarean section.

CASE REPORT

A 39-year-old female patient with history of Cesarean section presented with dysmenorrhea. Sonography revealed that a hypoechoic and anechoic multicystic complex, which was located on the right side of the pelvic cavity, had infiltrated the adjacent posterior wall of the uterus, and it was preoperatively misdiagnosed as ovarian cysts with suspected endometrioma. Laparoscopic surgery revealed multiple cystic lesions filled with clear yellow fluid on the posterior uterine wall instead of the adnexa. Laparoscopic uterine cystectomy was performed, and the patient's recovery was uneventful. Pathohistological and immunohistochemical examinations confirmed the diagnosis of uterine mesothelial cysts.

CONCLUSION

Uterine mesothelial cysts should be considered in the differential diagnosis of pelvic lesions. Increasing the awareness of this rare disease can contribute to improved evaluation, decision-making, and disease management.

Primary splenic multicystic peritoneal mesothelioma in a young healthy male

Multicystic peritoneal mesothelioma (BMPM) is a rare, usually benign tumor that arises from peritoneal mesothelial cells that most commonly occurs in women of reproductive age. Pathogenesis of these tumors is thought to come from chronic inflammation from prior surgery, endometriosis, trauma, or recurrent peritonitis. Here we report a case of primary splenic BMPM in a 20-year-old male with no past medical or surgical history and without any typical risk factors for this condition. He underwent an open splenectomy without complication. Pathology revealed an 18 × 4 × 11 cm3 spleen with a cyst occupying 75% of the splenic surface. Sections revealed a multilocular cyst with trabeculated walls and immunohistochemical staining positive for cytokeratin (AE1/AE3) consistent with BMPM. One year post operatively he remains asymptomatic; however, his interval computed tomography (CT) scan revealed several sub centimeter nodules that either represents small splenules or neoplastic implants. These will be followed with close interval imaging.

Malignant Peritoneal Mesothelioma: An In-Depth and Up-to-Date Review of Pathogenesis, Diagnosis, Management and Future Directions

Malignant peritoneal mesothelioma (MPM) is an extremely rare malignancy usually confined to the abdominal cavity. With an aggressive natural history, morbidity and mortality are consequences of progressive locoregional effects within the peritoneal cavity. The first reported case was in the early 20th century, however, due to the rare nature of the disease and a large gap in understanding of the clinicopathological effects, the next reported MPM cases were only published half a decade later. Since then, there has been exponential growth in our understanding of the disease, however, there are no prospective data and a paucity of literature regarding management. Traditionally, patients were treated with systemic therapy and the outcomes were very poor, with a median survival of less than one year. However, with the advent of cytoreductive surgery and locoregional chemotherapy, there have been significant improvements in survival. Even more recently, with an improved understanding of the molecular pathogenesis of MPM, there have been reports of improved outcomes with novel therapies. Given the disastrous natural history of MPM, the limited data, and the lack of universal treatment guidelines, an in-depth review of the past, present, and future of MPM is critical to improve treatment regimens and, subsequently, patient outcomes.

Thinking outside the pelvis: benign peritoneal multicystic mesothelioma of the ascending colon

Benign peritoneal multicystic mesothelioma is a rare tumor of the visceral peritoneum. The authors present an atypical case of a 74-year-old man who presented with a multicystic mesothelioma of the ascending colon.

A Rare Case of Calcified Simple Mesenteric Cyst in a 70-Year-Old Woman

Mesenteric cysts are one of the rare causes of intra-abdominal masses. They account for 1 in 100,000 cases in adults and 1 in 20,000 cases in children. Mesenteric cysts are commonly found in the small intestine, up to 60% of cases, and occasionally in the colon. The clinical presentation of patients with mesenteric cysts is so variable and nonspecific. It ranges from being asymptomatic to features of acute abdomen very rarely. Surgery is the treatment of choice. Complete excision with negative margins plays a curative role in avoiding the risk of recurrence as well. Here, we present the case of a 70-year-old woman who came to Hawassa University Comprehensive Specialized Hospital with abdominal swelling for a 5-month duration. She had an abdominal ultrasound, which suggested a calcified mesenteric cyst with internal hemorrhage. The patient was taken to the OR with the impression of an intra-abdominal mass for exploratory laparotomy. The mass was completely excised and was subjected to pathology, which turned out to be a calcified simple mesenteric cyst, and the purpose of this case report is to alert physicians that although the preoperative diagnosis of mesenteric cysts is difficult, it should be considered in the differential diagnosis of a patient presenting with an intra-abdominal mass.

Radiology of the Mesentery

The recent description and re-classification of the mesentery as an organ prompted renewed interest in its role in physiological and pathological processes. With an improved understanding of its anatomy, accurately and reliably assessing the mesentery with non-invasive radiological investigation becomes more feasible. Multi-detector computed tomography is the main radiological modality employed to assess the mesentery due to its speed, widespread availability, and diagnostic accuracy. Pathologies affecting the mesentery can be classified as primary or secondary mesenteropathies. Primary mesenteropathies originate in the mesentery and subsequently progress to involve other organ systems (e.g., mesenteric ischemia or mesenteric volvulus). Secondary mesenteropathies describe disease processes that originate elsewhere and progress to involve the mesentery with varying degrees of severity (e.g., lymphoma). The implementation of standardized radiological imaging protocols, nomenclature, and reporting format with regard to the mesentery will be essential in improving the assessment of mesenteric anatomy and various mesenteropathies. In this article, we describe and illustrate the current state of art in respect of the radiological assessment of the mesentery.

Benign multicystic peritoneal mesothelioma occurring in bilateral inguinal canals metachronously: a case report

BACKGROUND

Benign multicystic peritoneal mesothelioma (BMPM) is a benign tumor that usually occurs in middle-aged females. Although several published studies have reported the occurrence of this tumor in the abdominal cavity, few have documented its development in the inguinal region.

CASE PRESENTATION

We present a case of a 48-year-old female presenting with a bulge in her left inguinal region. Physical examination revealed a golf ball-sized nodule in the left inguinal region that could not be pushed back into the abdominal cavity. Contrast-enhanced computed tomography showed a multicystic tumor; therefore, the patient was diagnosed with inguinal hernia or hydrocele of the Nuck's canal. We performed surgical resection and hernia repair using the mesh plug method. The resected specimen was 80 mm in length and contained a multicystic tumor. Pathological examination showed that the cyst wall was lined by a single layer of cuboidal to single layer squamous epithelium. Immunohistochemistry revealed positivity for calretinin in the epithelial cells, for which a diagnosis of BMPM was established. The patient returned to our hospital after 5 years with symptoms similar to the previous episode, but this time in the right inguinal region. Imaging studies showed a tumor in the right inguinal region with the same characteristics as the previous one. The patient underwent tumor resection and hernia repair using the same technique. The resected tumor was 45 mm in length and had characteristics similar to the previously resected tumor. The presence of calretinin and D2-40 on immunohistochemistry led to the diagnosis of BMPM. There was no recurrence of BMPM for 33 months after the secondary surgery.

CONCLUSIONS

Here we present the first report of metachronous BMPM occurring in bilateral inguinal canals. Although the pathogenesis of BMPM remains unclear, reactive changes have been suggested to cause tumors originating from the groin. The treatment of choice for BMPM is surgical resection. For diagnosis, pathological examination with immunostaining can be useful. The most appropriate postoperative follow-up for inguinal BMPM is controversial, and the accumulation of more inguinal BMPM cases is needed.

Mesenteric Cyst with GI Symptoms: A Fluid Approach to Treatment-Case Report and Literature Review

Mesenteric cysts are defined as a heterogeneous group of intra-abdominal cystic lesions of the mesentery or omentum that may be found in any portion of the gastrointestinal tract from the duodenum to the rectum. The clinical condition is entirely asymptomatic in many patients, particularly with small cysts. The diagnosis is typically incidental and secondary to imaging performed for other purposes. In symptomatic patients, the clinical picture is characterized by nonspecific gastrointestinal signs and symptoms. Treatment may be surgical or via interventional radiology. We report the case of a 55-year-old female patient complaining of left-sided abdominal discomfort and constipation lasting three months. An abdominal ultrasound showed the presence of a 10 × 14 × 16 cm anechoic cystic mass filling the whole anterior and left abdominal cavity, confirmed by CT and MRI. The cyst, removed laparoscopically, was histologically a simple mesothelial cyst. We reviewed the international literature over the last 10 years of all cases with mesenteric cysts > 10 cm in evaluating gastrointestinal symptoms at diagnosis, histology, performed treatment, and outcome.

Acute presentation of multi-cystic peritoneal mesothelioma

Multi-cystic peritoneal mesothelioma (MCPM) is a rare intra-abdominal neoplasm that occurs most commonly in young females. The disease usually presents as an incidental finding or with sub-acute abdominal pain. The mainstay of treatment is complete excision; however, local recurrence frequently occurs and malignant transformation has been reported. We describe a unique case of MCPM that presented with acute abdominal pain.

A 32-year-old female presented with a 24-hour history of abdominal pain. Computed tomography abdomen demonstrated a low-density mass with surrounding inflammatory changes anterior to the ascending colon, which was initially thought to represent an abscess. A percutaneous drain was inserted; however, only clear fluid was aspirated and the lesion did not resolve. The patient subsequently underwent laparoscopy which identified a cystic structure overlying the ascending colon. The structure was excised whole with histology demonstrating MCPM. The patient recovered from surgery and will undergo a period of surveillance.

Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making

The peritoneal cavity is the second commonest site of mesothelioma after the pleural cavity. There are five histological types of peritoneal mesothelioma with variable symptomatology, clinical presentation and prognosis. Cystic mesothelioma is a borderline malignant neoplasm with a favourable prognosis, well-differentiated papillary mesothelioma is generally a low-grade malignancy, and all other varieties such as epithelioid, sarcomatoid and biphasic mesothelioma are highly malignant types of peritoneal mesothelioma with poor prognosis. Malignant peritoneal mesothelioma was considered inevitably fatal prior to the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected cases where long-term survival and cure could be achieved. However, the survival benefits following CRS and HIPEC mainly depend on completeness of cytoreduction, which come at the cost of high morbidity and potential mortality. Using the acronym 'PAUSE', we aimed at describing the key imaging findings that impact surgical decision-making in patients with peritoneal mesothelioma. PAUSE stands for peritoneal cancer index, ascites and abdominal wall disease, unfavourable sites of involvement, small bowel and mesenteric disease and extraperitoneal disease. Reporting components of 'PAUSE' is crucial for patient selection. Despite limitations of CT in accurately depicting the volume of disease, describing findings in terms of PAUSE plays an important role in excluding patients who might not benefit from CRS and HIPEC.

Multicystic peritoneal mesothelioma treated with cytoreductive surgery followed or not by hyperthermic intraperitoneal chemotherapy: results from a large multicentric cohort

BACKGROUND

Multicystic peritoneal mesothelioma (MCPM) is a rare, slowly growing, condition prone to recur after surgery. The role of hyperthermic intraperitoneal chemotherapy (HIPEC) added to complete cytoreductive surgery (CRS) remains controversial and difficult to assess. As patients are mostly reproductive age women, surgical approach, and fertility considerations are important aspects of the management. This observational retrospective review aimed to accurate treatment strategy reflections.

METHODS

The RENAPE database (French expert centers network) was analyzed over a 1999-2019 period. MCPM patients treated with CRS were included. A special focus on HIPEC, mini-invasive approach, and fertility considerations was performed.

RESULTS

Overall 60 patients (50 women) were included with a median PCI of 10 (4-14) allowing 97% of complete surgery, followed by HIPEC in 82% of patients. A quarter of patients had a laparoscopic approach. Twelve patients (20%) recurred with a 3-year recurrence free survival of 84.2% (95% confidence interval 74.7-95.0). The hazard of recurrence was numerically reduced among patients receiving HIPEC, however, not statistically significant (hazard ratio 0.41, 0.12-1.42, p = 0.200). A severe post-operative adverse event occurred in 22% of patients with five patients submitted to a subsequent reoperation. Among four patients with a childbearing desire, three were successful (two had a laparoscopic-CRS-HIPEC and one a conventional CRS without HIPEC).

CONCLUSION

MCPM patients treatment should aim at a complete CRS. The intraoperative treatment options as laparoscopic approach, fertility function sparing and HIPEC should be discussed in expert centers to propose the most appropriate strategy.

Mesothelial Cysts

OBJECTIVES

Peritoneal mesothelial cysts have been reported under various terms, including benign cystic mesothelioma, usually in the form of case reports/series, whereas extraperitoneal cases are rarely reported. Our objective was to report the detailed characteristics of cystic lesions of the serosal cavities.

METHODS

We retrospectively examined the clinicopathologic findings of a series of mesothelial cystic lesions (n = 79).

RESULTS

Most cases (n = 68, 86%) concerned the peritoneum, whereas 11 (14%) concerned the pericardium. No pleural cases were found. A total of 51 (64.5%) lesions were solitary, whereas 28 (35.5%) were multiple. Peritoneal lesions harbored a plump eosinophilic mesothelium and a loose connective stroma, whereas pericardial lesions showed a cuboidal/flattened mesothelium, collagenous stroma, intense inflammation, and other tissue types, like adipose and muscle tissue. Solitary peritoneal lesions are usually extrapelvic and found in older patients incidentally during other surgeries, whereas multiple lesions are found in younger patients and usually in the pelvis. The lesions show a benign clinical course with rare recurrences but no malignant transformation.

CONCLUSIONS

Most mesothelial cysts are peritoneal and rarely pericardial. Peritoneal cysts differ from pericardial cysts. Peritoneal solitary lesions differ from multiple lesions, also suggesting their pathogenetic differences.

New insights in the pathology of peritoneal surface malignancy

Pathology is central to the management of peritoneal surface malignancy. This article highlights some recent advances that have had an impact on patient management or could do so in the near future. Malignant peritoneal mesothelioma, particularly the epithelioid subtype, is amenable to radical therapy in selected cases, and factors such as ki67 proliferation index, expression of BAP1 and mutation in CDKN2A show promise as prognostic indicators. Our understanding of multicystic mesothelioma has improved in recent years; it is a true neoplasm for which surgery may be indicated. Serous carcinomas involving the peritoneum are now known to originate from tubal epithelium. They are of two distinct types, high grade and low grade, which are now recognized as different neoplasms with distinctive features, oncogenesis and behavior. Pseudomyxoma peritonei (PMP) is an unusual condition that usually arises from an appendiceal mucinous neoplasm. Recent consensus in the classification and nomenclature of these lesions is discussed, including the distinction between low grade and high grade appendiceal mucinous neoplasms (HAMN), and the diagnostic criteria for appendiceal adenocarcinoma. PMP is divided into four prognostic groups: acellular mucin, low grade mucinous carcinoma peritonei, high grade mucinous carcinoma peritonei, and high grade mucinous carcinoma peritonei with signet ring cells. The pseudomyxoma microbiome is a promising area for clinical intervention but has been the subject of little research activity. Goblet cell adenocarcinoma (previously known as 'goblet cell carcinoid') is a distinctive type of appendiceal adenocarcinoma. Its behavior correlates with histologic features, but no general consensus for classification has been reached.

Pathological Discrepancy: Simple Mesenteric Cyst vs. Mesenteric Lymphangioma

Introduction

Both mesenteric cysts and cystic lymphangiomas are scarce and clinically and radiologically almost identical derivatives, but their histological structure is fundamentally different. Case Presentation. A 52-year-old woman was consulted by a surgeon for a derivative felt in her abdomen. The patient said she felt a growing derivative in the abdomen about a month ago. After consulting and testing, a sigmoid colon mesenteric cyst (13 cm × 11 cm × 10 cm) was found. Complete excision of the cyst within healthy tissues was performed through laparotomy. The surgery had no complications. The initial pathological answer was a simple mesothelial cyst (a rare histological finding). However, immunohistochemical tests were performed that showed that diagnosis was mesenteric cystic lymphangioma (ML). Cystic lymphangiomas that have a link to the mesentery have been described less than 200 times.

Conclusions

Final differential diagnosis between different cystic derivatives is possible only based on histopathological examinations. Mesenteric lymphangioma is most common at a very young age, but in rare cases, it also occurs in adults. All clinicians should increase their awareness of the disease.

Outcomes of multicystic peritoneal mesothelioma treatment with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND

Multicystic peritoneal mesothelioma (MCPM) is a rare neoplasm, generally considered a borderline malignancy, best treated by cytoreductive surgery (CRS) to remove macroscopic disease, combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Owing to its rarity, little has been published on clinical presentation, clinical behaviour over time, or an optimal treatment approach.

METHODS

A prospectively developed peritoneal malignancy database was interrogated for the years 2001-2018. Details on all patients with MCPM as a definitive diagnosis after CRS and HIPEC were analysed, including previous interventions, mode of presentation, surgical treatment, postoperative outcomes, and late follow-up information from abdominal CT and tumour markers.

RESULTS

Some 40 patients with MCPM underwent CRS and HIPEC between 2001 and 2018. Of these, 32 presented with abdominal pain, distension or bloating, six patients presented with recurrence following previous surgery at the referring hospitals, and two had coincidental diagnoses during a surgical procedure. CRS involved peritonectomy in all 40 patients. Bowel resection was required in 18 patients, and seven had a temporary stoma. Thirty-eight patients were considered to have undergone a complete macroscopic tumour removal (completeness of cytoreduction CC0), and two had residual tumour nodules less than 2.5 mm in size, classified as CC1. Median duration of follow-up was 65 (range 48-79) months. There were no deaths during follow-up. The Kaplan-Meier-predicted recurrence-free interval was 115.4 months.

CONCLUSION

MCPM is a rare peritoneal neoplasm with a heterogeneous pattern of presentation. CRS and HIPEC is an effective management option for this group of patients, with favourable long-term survival.

CRS/HIPEC with Major Organ Resection in Peritoneal Mesothelioma Does not Impact Major Complications or Overall Survival: A Retrospective Cohort Study of the US HIPEC Collaborative

INTRODUCTION

CRS/HIPEC is thought to confer a survival advantage for patients with malignant peritoneal mesothelioma (MPM). However, the impact of nonperitoneal organ resection is not clearly defined. We evaluated the impact of major organ resection (MOR) on postoperative outcomes and overall survival (OS).

PATIENTS AND METHODS

The US HIPEC collaborative database (2000-2017) was reviewed for MPM patients who underwent CRS/HIPEC. MOR was defined as total or partial resection of diaphragm, stomach, spleen, pancreas, small bowel, colon, rectum, kidney, ureter, bladder, and/or uterus. MOR was categorized as 0, 1, or 2+ organs.

RESULTS

A total of 174 patients were identified. Median PCI was 16 (3-39). The distribution of patients with MOR-0, MOR-1, and MOR-2+ was 94, 45, and 35 patients, respectively. MOR-1 and MOR-2+ groups had a higher frequency of any complication compared with MOR-0 (57.8%, 74.3%, and 48.9%, respectively, p = 0.035), but Clavien 3/4 complications were similar. Median length of stay was slightly higher in the MOR-1 and MOR-2+ groups (10 and 11 days) compared with the MOR-0 cohort (9 days, p = 0.005). Incomplete cytoreduction, ASA class 4, and male gender were associated with increased mortality on unadjusted analysis; however, their impact on OS was attenuated on multivariable analysis. MOR was not associated with OS based on these data (MOR-1: HR 1.67, 95% CI 0.59-4.74; MOR-2+ : HR 0.77, 95% CI 0.22-2.69).

CONCLUSIONS

MOR was not associated with an increase in major complications or worse OS in patients undergoing CRS/HIPEC for MPM and should be considered, if necessary, to achieve complete cytoreduction for MPM patients.

Benign multi-cystic peritoneal mesothelioma of the porta hepatis

INTRODUCTION

Our case report describes a patient where multiple laparoscopies five years from initial presentation of symptoms were performed prior to laparotomy for benign multi-cystic peritoneal mesothelioma (BMPM), which has not been documented.

PRESENTATION

A 61-year-old woman presented with years of chronic abdominal pain. Computerized tomography (CT) demonstrated a multi-cystic mass near the porta hepatis, and ultrasound was concerning for contained gallbladder perforation. Fine needle aspiration (FNA) demonstrated benign ductal epithelial cells in a background of mucin and bile without the presence of malignant cells. During laparotomy, a cystic mass attached to the porta hepatis seen emanating from the small bowel mesentery, and additional small cystic lesions through the abdomen were removed. The specimen, measuring 26 × 18 × 8 cm, showed multi-loculated cysts filled with serous fluid.

DISCUSSION

BMPM is a rare neoplasm of mesothelioma cells originating from serosa of viscous organs. BMPMs appear as cystic structures with thin walls containing mucinous/gelatinous fluid. Microscopic features include a lack of invasion and no increased cellularity in the stroma, with or without inflammation (Myers & Babiker, 2018). It is postulated to be either a reactive or neoplastic process. There is no gold-standard treatment for BMPM. Our case is unique in the sense that our patient required several surgical biopsies before final diagnosis could be made.

CONCLUSION

This case highlights the difficulty of diagnosing BMPM and differentiating it from malignant diseases that can present similarly and can be associated with significantly worse prognosis. Defined management strategies have yet to be demonstrated.

Multicystic peritoneal mesothelioma treated with complete cytoreductive surgery, peritonectomy and hyperthermic intra-peritoneal chemotherapy-A case report

•

Multicystic Peritoneal mesothelioma is a distinct type of peritoneal mesothelioma with borderline malignant potential and tendency to recur after tumor debulking.

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Morphologically MCPM has grapelike cysts filled with clear fluid and microscopically it has cystic spaces lined by cuboidal epithelium.

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There are areas of increased proliferative activity in the background of benign cyst representing potential for aggressiveness.

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Peritoneal free floating cysts can be formed from disintegration of main mass and deposit in other areas to form metastatic deposits.

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Comprehensive treatment – Complete cytoreduction, involved peritonectomy and HIPEC is required for treatment of macroscopic tumor and microscopic residue.

Background

Multicystic Peritoneal mesothelioma is a rare and distinct variety of peritoneal mesothelioma with borderline malignant potential. Conventional Tumor bulking has been associated with recurrence of 45–50 %. Hence a comprehensive treatment with Complete cytoreductive surgery with involved field peritonectomy (CRS) and Hyperthermic Intra-peritoneal chemotherapy (HIPEC) is being increasingly adopted for MCPM.

Case presentation

A 47 year old lady evaluated for peri-menopausal disturbance was diagnosed to have a multicystic lesion in the pelvis. With a preoperative suspicion of diagnosis of pseudomyxoma peritonei, CRS with HIPEC was planned. On exploration a diffuse multicystic mass was found in omentum and pouch of douglas with typical morphological features of MCPM. Complete cytoreduction was achieved with anterolateral and sub-diaphragmatic peritonectomy, omentectomy and panhystrectomy. HIPEC was performed with cisplatin 50 mg/m² for 40 min. Pathological examination revealed MCPM of omentum and uterine surface with focal clusters of mesothelial proliferation. However there was low proliferative activity 1–2 %.

Discussion

MCPM presents with wide spread peritoneal spread but with relative sparing of visceral invasion. Literature review suggests the disease spread is similar to PMP and treatment with CCRS and HIPEC has yielded long term survivals in MCPM.

Conclusions

This patient with voluminous disease burden in abdomen required surgical management and HIPEC for her condition. Whether CCRS alone without HIPEC can be an alternative for limited disease will be interesting research for future clinical reports.

Benign multicystic peritoneal mesothelioma: literature review and update

Benign multicystic peritoneal mesothelioma (BMPM) is a rare peritoneal tumor diagnosed predominantly in pre-menopausal women. Associated risk factors include endometriosis and pelvic inflammatory disease in women, and prior abdominal surgery in both genders. To date, the pathogenesis of this disease remains controversial with possible etiologies, including a neoplastic versus a reactive process. Given the risk factors, some authors believe that this disease is secondary to a reactive process. However, because some studies describe cases where there is no prior surgical history or inflammatory milieu present, and because of this entity’s predilection for recurrence, some authors believe the origin to be neoplastic. Some genetic and familial associations have also been reported. Malignant transformation is extremely rare, with only two cases reported in the literature, despite the recurrence potential. Like the etiology, the name of this entity is also controversial. Some authors prefer the term “peritoneal inclusion cyst (PCM)” instead of “benign cystic mesothelioma” and argue that the term mesothelioma should only be used when there is evidence of atypia. Most cases of BMPM are discovered incidentally. Others reflect sequela of tumor mass effect. It appears intra-operatively as large, multi-focal, cystic lesions in the peritoneal and pelvic cavity. Diagnosis is achieved through surgical sampling with histopathological examination. Immunobiologically, BMPM exhibits multiple small cystic spaces with flattened lining containing calretinin positive cells without atypical features, mitotic figures, or tissue invasion. Treatment includes cytoreductive surgery. Here we present a case of BMPM in a 60-year-old male – a rare disease in an uncommon patient population.

Multicystic and diffuse malignant peritoneal mesothelioma in children

BACKGROUND

Malignant and multicystic peritoneal mesotheliomas are extremely rare tumors in children, developing from mesothelial cells. No specific guidelines are available at this age.

METHODS

We performed a retrospective analysis of all identified children (< 18-year-old) treated in France from 1987 to 2017 for a diffuse malignant peritoneal mesothelioma (DMPM) or a multicystic peritoneal mesothelioma (MCPM).

RESULTS

Fourteen patients (5 males and nine females), aged 2.2 to 17.5 years, were included. The most frequent presenting symptoms were abdominal pain, ascitis, and alteration in the general condition. Eight patients had epithelioid mesothelioma, three had biphasic mesothelioma, and three had MCPM. Eight patients with DMPM diagnosis received cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Among them, six patients had neoadjuvant systemic chemotherapy, one patient, post-operative chemotherapy, and one patient CRS and HIPEC only. Three patients received only systemic chemotherapy. All patients with MCPM had only surgery. After a median follow-up of seven years (2-15), six patients (6/11; one death) with DMPM and two patients (two/three) with MCPM had a local and distant recurrences.

CONCLUSION

Peritoneal mesothelioma in children is a rare condition with difficult diagnosis and high risk of recurrence. Worldwide interdisciplinary collaboration and networking are mandatory to help diagnosis and provide harmonious treatment guidelines.

Imaging of Benign Adnexal Disease

This article provides an overview of the imaging evaluation of benign ovarian and adnexal masses in premenopausal and postmenopausal women and lesions discovered during pregnancy. Current imaging techniques are discussed, including pitfalls and differential diagnosis when necessary, as well as management. It also reviews the now well-established American College of Radiology (ACR)/Society of Radiologists in Ultrasound consensus guidelines and covers the more recently introduced Ovarian-Adnexal Reporting and Data System by the ACR and the recently published ADNEx Scoring System.

Peritoneal mesothelioma in Sweden: A population-based study

The study aim was to report survival and morbidity of all patients in Sweden with peritoneal mesothelioma treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) as well as investigate whether the survival has increased on a population level since this treatment was nationalized 2011. Study data were collected from the Swedish HIPEC registry and the Swedish National Cancer Registry. All patients with peritoneal mesothelioma scheduled for CRS/HIPEC treatment in Sweden January 2011 to March 2018 were retrieved from the Swedish HIPEC registry. Clinicopathological and survival data were collected. For population‐level analysis, all patients with diffuse malignant peritoneal mesothelioma (DMPM) were identified from the Swedish National Cancer Registry and data were retrieved from two separate 5‐year time periods: 1999‐2003 and 2011‐2015. Thirty‐two patients were accepted for CRS/HIPEC. Four were open/close cases. Two‐year survival rate was 84% or 59% when excluding borderline peritoneal mesotheliomas (n = 17). Median overall survival was not reached. Grade III‐IV Clavien‐Dindo events occurred in 22% with no mortality. From the national cancer registry, 102 DMPM cases were retrieved: 40 cases between 1999 and 2003, and 62 cases between 2011 and 2015 (corresponding to an increase from 0.9 to 1.24/million/year, P = .04). Six patients (10%) received CRS/HIPEC in the second period. Median OS increased between periods from 7 to 15 months and 5‐year survival from 14% to 29% (P = .03). Peritoneal mesothelioma of both borderline and DMPM subtypes undergoing CRS/HIPEC have good long‐term survival. The incidence of DMPM in Sweden has increased. Overall survival has increased alongside the introduction of CRS/HIPEC, which may be a contributing factor.

Multicystic peritoneal mesothelioma: a systematic review of the literature

Multicystic peritoneal mesothelioma (MCPM) is a particularly rare and benign neoplasm that arises from the peritoneum in reproductive aged females. Its etiopathogenesis is still unclear. The current prevailing theory supports the idea that the tumor is the result of an excessive inflammatory process. Because of a lack of clinical and imaging presentation, the diagnosis is intricate, and heavily relies on case reports and short studies. A histological analysis with immunohistochemistry is required for a definitive diagnosis. To date, there is no standard treatment recommended for MCPM. However, some studies suggest proceeding with a cytoreductive surgery and a hyperthermic intraperitoneal chemotherapy combining CISPLATIN and DOXORUBICIN, due to a high incidence of recurrence rate after medical treatment or surgery alone and potential malignant transformation.

Diagnosis and Management of an Unusual Cyst 3 Years After Sacrocolpopexy

BACKGROUND

Peritoneal inclusion cysts (PICs) are uncommon tumours that can pose diagnostic challenges. This report describes an unusual etiology and management of recurrent pelvic organ prolapse.

CASE

A 48-year-old premenopausal woman presented with recurrent prolapse and urinary frequency after total abdominal hysterectomy and synthetic mesh sacrocolpopexy. On examination, a stage II rectoenterocele was noted. Her post-void residual was 760 mL as measured by bladder scanner, discrepant with in-and-out catheterization. Pelvic ultrasound revealed a 19-cm cystic pelvic mass. At laparoscopy a PIC was identified, and cystectomy, uterosacral plication, and Moschcowitz culdoplasty were performed. Complete symptom resolution was documented at 4 weeks and 3 months postoperatively.

CONCLUSION

PICs should be included in the differential diagnosis of recurrent prolapse. Prolapse symptoms attributable to PICs can be treated with laparoscopic cystectomy.

Benign multicystic mesothelioma arising from the tunica vaginalis

Benign multicystic mesothelioma is an extremely rare neoplasm usually arising from the visceral mesothelium of the peritoneal cavity typically presenting in young to middle-aged women. It has been deemed an indolent tumour with a possible heritable nature, but also a possible reactive neoplasm secondary to trauma. Diagnosis relies on identifying characteristic histology of cysts separated by loose connective tissue stroma and lined by pale, flat or cuboidal mesothelial cells. A 74-year-old male presented with a painless, enlarging scrotal swelling thought to be either an epididymal cyst or hydrocele. He underwent radical orchiectomy and benign multicystic mesothelioma of the tunica vaginalis was characterized on macroscopy and microscopic examination. The potential for malignant transformation of these tumours has not been demonstrated, but they are known to recur. This infrequent presentation of a rare and poorly understood tumour with description of histologic findings may allow for improved diagnosis in other cases.

Prevention and Treatment of Peritoneal Metastases: a Comprehensive Review

Peritoneal metastases may occur from a majority of cancers that occur within the abdomen or pelvis. When cancer spread to the peritoneal surfaces is documented, a decision regarding palliation versus an aggressive approach using cytoreductive surgery (CRS) and hyperthermic perioperative intraperitoneal chemotherapy (HIPEC) must be made. This decision is dependent on a well-defined group of prognostic indicators. In addition to treatment, prevention of peritoneal metastases may be an option. The clinical and pathologic features of a primary cancer can be used to select perioperative treatments that may prevent cancer cells within the abdomen and pelvis from progressing to established peritoneal metastases. In some clinical situations with appendiceal and colorectal cancers, the clinical or histopathologic features may indicate that second-look surgery plus perioperative chemotherapy should occur. Peritoneal metastases should always be considered by the multidisciplinary team for treatment or prevention.

Benign Multicystic Peritoneal Mesothelioma in a Male Patient with Previous Wilms' Tumor: A Case Report and Review of the Literature

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, more common in females of reproductive age, which arises from the peritoneal mesothelium. A 33-year-old male presented to our unit with abdominal pain and constipation. His past medical history included a previous unilateral nephrectomy for Wilms' tumor and the previous incidental finding of some intra-abdominal cystic formations at the level of the mesentery. After performing a CT scan, an exploratory laparotomy was done and a voluminous cystic mesenteric mass, composed of 3 confluent formations, was observed. Some other similar but significantly smaller lesions were found. An en bloc resection of the mesenteric mass together with the corresponding intestinal loops, an appendicectomy, and some peritoneal biopsies were performed. The postoperative period was complicated by a peritonitis due to dehiscence of the intestinal anastomosis, which required another operation, and a delayed return of normal bowel function, which was resolved through prokinetic therapy. Through histological examination, a BMPM was diagnosed. At 8 months of follow-up, the patient is free of symptoms. BMPM exact etiopathogenesis still remains uncertain. Given his high recurrence rate, a long-term follow-up is recommended.

Peritoneal Metastases from Gastrointestinal Cancer

PURPOSE OF REVIEW

Peritoneal metastases may occur from a majority of cancers that occur within the abdomen or pelvis. When cancer spread to the peritoneal surfaces is documented, a decision regarding palliation vs. an aggressive approach using cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy must be made. The perioperative chemotherapy may be hyperthermic intraperitoneal chemotherapy (HIPEC) administered in the operating room or early postoperative intraperitoneal chemotherapy (EPIC) administered in the first 4 or 5 postoperative days.

RECENT FINDINGS

This decision is dependent on a well-defined group of prognostic indicators. In addition to treatment, the clinical and pathologic features of a primary cancer can be used to select perioperative treatments that may prevent cancer cells within the abdomen and pelvis from progressing to established peritoneal metastases. In some clinical situations with appendiceal and colorectal cancers, the clinical or histopathologic features may indicate that second-look surgery plus perioperative chemotherapy should occur. Peritoneal metastases should always be considered for treatment or prevention.

An interesting mediastinal cyst case: Benign cystic mesothelioma

Anterior mediastinal, well-defined, ametabolic cystic lesion was detected incidentally in a 69-year-old male patient. Uniportal videothoracoscopic surgery was performed to the lesion for diagnosis and treatment purposes. Histopathological findings were in accordance with "benign cystic mesothelioma". Benign cystic mesothelioma has been defined in the abdomen, particularly among females of reproductive age. Benign cystic mesothelioma originating from mediastinal pleura is very rare entity and was not defined in the literature. To our knowledge, we present this rare and interesting mediastinal cystic lesion for the first time in the literature.

Multicystic mesothelioma: Operative and long-term outcomes with cytoreductive surgery and hyperthermic intra peritoneal chemotherapy

BACKGROUND

Multicystic peritoneal mesothelioma (MCPM) is an extremely rare disease with 40-50% rate of recurrence after surgical debulking. Due to the recurrent nature of the disease, the option of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) was offered for this condition. In the present study we aimed to describe the outcomes of this strategy in a single center cohort.

METHODS

We retrospectively reviewed a prospectively collected database of all patients with MCPM that underwent the combined procedure in our center. Clinical presentation, operative procedures and outcomes were reviewed.

RESULTS

Between August 1997 and October 2017, 19 patients with MCPM underwent 20 cytoreduction and HIPEC procedures in our center. The majority of the patients were females (n = 17, 89%), and mean age was 42, as reported in other series. Disease extent, as measured by mean peritoneal carcinomatosis index (PCI) was 15.5 ± 9.9 and total number of procedures performed 6.7 ± 2.6. Major complications occurred in 3 (15%) patients, with no perioperative mortality. After a median of follow-up of 69 months (range 4-220) all patients were alive and 4 patients had recurrence (21%). Patients with high PCI (defined by median PCI) had shorter recurrence free survival (RFS) than patient with low PCI (mean RFS = 106.4 ± 6.6 for high PCI vs. 125.6 ± 34.1 for low PCI, p = 0.03).

CONCLUSION

Cytoreduction and HIPEC offer low recurrence rate and prolonged mean RFS for patients with MCPM. The combined procedure can be offered with acceptable morbidity in specialized centers.

Benign multicystic mesothelioma and peritoneal inclusion cysts: are they the same clinical and histopathological entities? A systematic review to find an evidence-based management

PURPOSE

Peritoneal mesothelial cysts (PMC) are a clinical dilemma because of their true pathogenic nature. Many definitions have been associated with PMC, including "benign multicystic mesothelioma", "cystic mesothelioma", "multilocular peritoneal inclusion cysts", ''inflammatory cysts of the peritoneum" or "postoperative peritoneal cyst".

METHODS

We herein performed a systematic review of the literature focusing on clinical and histopathological aspects of PMC, diagnosis, and therapies. Moreover, we described our experience with a case of PMC in a young female.

RESULTS

Since there is often a history of prior surgery or inflammatory disease, most authors consider PMC of reactive origin. However, in some cases they occur without any documentable signs of disease or injury. A variety of clinical findings can complicate the preoperative assessment and a multitude of histological pictures may potentially lead to a misdiagnosis. The absence of a uniform treatment strategy and lack of long-term follow-up often hinder the accurate definition leading to unnecessary or unnecessarily aggressive therapy.

CONCLUSIONS

PMC are more common than had previously been thought. Most authors consider them non-neoplastic; thus the designation of "peritoneal inclusion cyst" is preferable. The term "mesothelioma" should be used only in cases of histological evidences of atypia. The high rates of recurrence suggest that the goal of treatment should not be necessarily complete eradication, but symptomatic relief through individualized treatment. This is a topic of particular importance, especially in young female where recurrence rates could be lower than those reported in adults and where an improperly aggressive treatment could have repercussions on fertility.

Thin-Walled Cysts as a Pathognomonic CT Finding in Cystic Mesothelioma

Aim

Cystic mesothelioma is a rare disease that results in abdominal distention and poorly defined abdominal pain. Diagnosis has always been made by tissue biopsy rather than by radiologic studies.

Materials and methods

Our experience with 7 patients with cystic mesothelioma includes 4 patients who had not had prior surgery before the performance of a high resolution CT scan. A special review of the radiology of these cases was performed in order to identify any pathognomonic signs of this disease.

Results

In all patients who did not have a distortion of the radiologic images (as a result of surgical interventions) prior to the performance of a high resolution CT scan at our institution, a pathognomonic thin-wall cystic structure located within the gelatinous appearing mass was observed. These thin-walled cysts were of variable size and preferentially located within the greater omentum, pelvis and beneath the right hemidiaphragm.

Conclusion

Cystic mesothelioma can be diagnosed preoperatively by a high resolution abdominal and pelvic CT. The thin-walled cysts with great variation in size are located beneath the right hemidiaphragm, within the greater omentum and in the pelvis. No other disease with these radiologic findings has been identified.

Benign Multicystic Peritoneal Mesothelioma Associated with Hydronephrosis and Colovesical Fistula Formation: Report of a Case

Mesotheliomas usually arise from the pleura and are malignant. We report an unusual case of benign peritoneal mesothelioma presenting in a 59-year-old woman. The disease resulted in bilateral hydronephrosis, colovesical fistula formation, recurrent small bowel obstruction and chronic abdominal pain. To date only a handful of cases have been reported and to the best of our knowledge, none has been so aggressive.

Benign multicystic peritoneal mesothelioma treated with laparoendoscopic single site surgery: a case report and review of the literature

Benign multicystic peritoneal mesothelioma (BMPM) is rare and difficult to diagnose before surgery. We report a case of BMPM incidentally discovered during laparoendoscopic single site surgery (LESS) for treatment of a pelvic mass. A 47-year-old Korean menopaused woman presented to our outpatient clinic with a pelvic mass. She had a history of right ovary cystectomy with adhesiolysis at a local hospital in 2010. Imaging study of the pelvis revealed a multilocular cystic mass. LESS was performed and multiple grapelike clusters of cysts were seen in the uterus, cul-de-sac, both adnexa, pelvic wall, and omentum. The appendix was grossly free. Frozen biopsy confirmed BMPM. Excision of multiple cyst clusters of cysts, resection of the uterus with both adnexa, appendectomy, omentectomy, and adhesiolysis were performed with LESS. She is well for 2 years with no recurrence. BMPM should be included in the differential diagnosis when small multichamber cystic mass is found on ultrasonography.

Clinical presentation, diagnosis, classification and management of peritoneal mesothelioma: a review

Peritoneal mesothelioma (PM) is an uncommon but a serious, and often, fatal primary peritoneal tumour, with increasing incidence worldwide. Conventional systemic chemotherapy, generally based on experience with pleural mesothelioma, usually has disappointing results considering PM as a terminal condition. Patients usually present with non-specific symptoms of abdominal distension and pain making the diagnosis challenging. As PM is confined to the abdomen for all, or much, of its clinical course, a multimodality treatment combining cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has emerged as a new standard of care, and has been reported to achieve promising survival outcomes and local disease control in selected patients with PM. This review updates the presentation, diagnosis, classification and treatment strategies for PM.

Benign Multicystic Peritoneal Mesothelioma: A Rare Condition in an Uncommon Gender

Benign Multicystic Peritoneal Mesothelioma (BMPM) is a rare condition that arises from the abdominal peritoneum. Fewer than 200 cases have been reported worldwide. BMPM usually affects premenopausal women and is extremely rare in men. Many factors are suspected to contribute to its development, such as previous surgery, endometriosis, and familial Mediterranean fever. The main management is surgical resection; however, it is estimated that the recurrence rate is up to 50%. Malignant transformation is rare. We report a case series of three male patients who were diagnosed with BMPM and were treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

Laparoscopic treatment of retroperitoneal cystic mesothelioma. Two cases reported

Retroperitoneal cystic mesothelioma is a very rare lesion. The pathogeny is unclear and establishing a preoperative diagnosis versus others retroperitoneal cystic lesions is difficult. Thus, with increasing experience in laparoscopic retroperitoneal surgery, the use of this approach for exploration of a retroperitoneal mass of unknown origin may provide an alternative to classic open surgery and all the benefits of laparoscopy. We present two cases treated laparoscopycally and review the literature.

The first case of benign multicystic mesothelioma presenting as a splenic mass

Multicystic mesothelioma (MM) is a relatively rare tumour arising in the pelvic peritoneum of the tuboovarian region of young woman. Exceptionally, MM occurs on the serosal surfaces of various organs including kidney, bladder, lymph nodes, and liver. We report here the first case of MM wherein a 58-year-old woman with a previous history of endometriosis of the right ovary presented with a large multicystic mass of the spleen. The diagnosis of MM was made on a surgical specimen after splenectomy. A histopathologic examination is always necessary for the diagnosis of MM which should be differentiated from other lesions particularly from cystic lymphangioma. At one year follow-up, the patient had no evidence of recurrence. Despite the high frequency of local recurrences, MM is a benign lesion and ‘en bloc’ surgical excision with prolonged follow-ups is the treatment of choice.

Benign Cystic Mesothelioma Misdiagnosed as Peritoneal Carcinomatosis

Benign cystic mesothelioma (BCM) is a rare benign disease that forms multicystic masses in the abdomen, pelvis, and retroperitoneum. It occurs predominantly in young to middle-aged women. The majority of cases were associated with a history of abdominal or pelvic operation, a history of endometriosis, and pelvic inflammatory disease. We present a unique case of BCM which is different to the previous cases. The patient was a 52-year-old man showing features of peritoneal carcinomatosis accompanied by ascites on abdominal computed tomography scans. We herein report a case of BCM misdiagnosed with peritoneal carcinomatosis.

Pediatric Benign Cystic Peritoneal Mesothelioma

BACKGROUND

Benign cystic peritoneal mesothelioma is a rare tumor comprising multiple cysts typically found within the abdominal cavity. Although the literature has numerous accounts of this entity in adults, only a handful of cases have been published regarding its presence in the pediatric population.

CASE

We present the case of a prepubertal 10-year-old girl with the finding of benign cystic peritoneal mesothelioma at laparoscopy for suspected appendicitis, the management, and outcome.

SUMMARY AND CONCLUSION

Although benign cystic peritoneal mesothelioma can be treated with primary excision, the high recurrence rate in adult cases of this disease necessitates the need for long-term follow-up of these patients and provides a challenge to surgeons in providing continuing care.