Peritoneal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients

Benign cystic mesothelioma: A case report on the presentation of an unusual tumor

Introduction

Benign cystic mesothelioma of the peritoneum is a rare, benign abdominal tumor. It can present with vague signs and symptoms and is often found on imaging or incidentally during surgery.

Presentation of case

We report the case of a 30-year-old man presenting with acute abdominal pain that radiated to the right iliac fossa. No masses were found on superficial or deep palpation or on conducting a sonography. The patient underwent a diagnostic laparoscopy with an appendectomy, which revealed a perforated appendix and two cysts in the pelvis and iliac fossa.

Discussion

A benign cystic mesothelioma is an inclusion cyst found in the peritoneal cavity and has no specific clinical presentation. It can be symptomatic or found incidentally during surgery. Benign cystic mesotheliomas have a high recurrence rate and may undergo malignant transformation.

Conclusion

Complete surgical excision of benign cystic mesothelioma must always be the first step of the treatment plan for this condition. It is difficult to treat with no evidence-based treatment modality available; thus, treatment should only be undertaken in a specialized center.

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Benign cystic mesothelioma of the peritoneum is presents with vague symptoms.

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It can be symptomatic or found incidentally during surgery.

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To date, only 140 cases have been reported in the literature.

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Diagnosis is generally made via microscopic examination of the specimen.

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Mainstay of treatment for this tumor is complete surgical excision.

Multicystic peritoneal tumor in two layer hens

In chicken, peritoneal cystic lesions have not been clearly categorized. In this study, diffuse peritoneal multiple cysts were observed in two layer hens. The cysts in the serosa were lined with single layers of squamous or cuboidal cells. The papillary proliferations of columnar cells were also observed in one case. The smooth muscle layer or mass were observed around the cysts in both cases. The cystic lining cells were positive for pan-cytokeratin, vimentin, S100 and Wilms tumor 1. Ultrastructurally, they had sparsely microvilli on the luminal surface. The histological results indicated the present cases were multicystic mesothelioma, but also had characteristics of Mullerian epithelium. This is the first report describing the detailed pathological feature of unique multicystic tumor in chicken.

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.

Multicystic Mesothelioma

The immunohistochemical and histochemical findings of five multicystic mesothe-liomas, including a unique case of inguinal soft tissue location, are reported. The results of this study indicate that the histochemical and immunohistochemical profiles of multicystic mesothelioma parallel those of malignant mesothelioma.

Benign multicystic peritoneal mesothelioma mimicking recurrence of an ovarian borderline tumor: a case report

Introduction

Benign multicystic peritoneal mesothelioma is an extremely rare tumor that occurs mainly in women in their reproductive age. Its preoperative diagnosis and adequate treatment are quite difficult to attain.

Case presentation

Our patient was a 23-year-old Japanese woman who had a history of right oophorectomy and left ovarian cystectomy for an ovarian tumor at 20 years of age. The left ovarian tumor had been diagnosed on histology as a mucinous borderline tumor. Two years and nine months after the initial operation, multiple cysts were found in our patient. A laparotomy was performed and her uterus, left ovary, omentum and pelvic lymph nodes were removed due to suspicion of recurrence of the borderline tumor. A histological examination, however, revealed that the cysts were not a recurrence of the borderline tumor but rather benign multicystic peritoneal mesothelioma. There were no residual lesions and our patient was followed up with ultrasonography. She remains free from recurrence nine months after treatment.

Conclusion

We report a case of benign multicystic peritoneal mesothelioma mimicking recurrence of an ovarian borderline tumor. Benign multicystic peritoneal mesothelioma should be suspected when a multicystic lesion is present in the pelvis as in the case presented here, especially in patients with previous abdominal surgery.

Peritoneal inclusion cysts in adolescent females: a clinicopathological characterization of four cases

STUDY OBJECTIVE

To identify adolescent females with peritoneal inclusion cysts and characterize the clinicopathologic features.

DESIGN

Observational and chart review along with immunohistochemical studies.

SETTING

University pediatric and adolescent clinic.

RESULTS

Medical records of all subjects, ages 10-18 years, diagnosed with peritoneal inclusion cysts over a 4-year period were retrospectively reviewed. Four patients, ages 11-16 years (mean, 13.8 yrs) were identified. Pelvic pain was the most common presenting symptom. No palpable abdominal or pelvic masses were detected. However, pelvic lesions were identified by radiographic studies in three of the four patients. Half experienced tenderness on examination. With one exception, all had a prior history of abdominal surgery. Twelve peritoneal inclusion cysts were identified, ranging from 1 cm to 7 cm in greatest diameter. Most were uninvolved in coexisting adhesions and non-adherent to pelvic or abdominal structures. Each had a well-defined pedicle connection to the peritoneum. No associated complications were identified. Their appearance conformed to established morphologic and immunohistochemical criteria, although accompanying mesothelial-associated changes occasionally reported in other populations were not detected. No recurrences were recorded.

CONCLUSION

Young female adolescents with peritoneal inclusion cysts share presenting symptoms and histories of previous abdominal surgery similar to those reported in older female adolescents and adults. A palpable mass may not be detected on examination, but can often be identified using radiographic studies. Our cases differ from previous reports by smaller cyst size, presence of a pedicle, and uncomplicated gross and microscopic appearances. Additionally, local recurrences and associated complications occurred less than reported in adults.

Benign multicystic peritoneal mesothelioma: A case report and review of the literature

Benign multicystic peritoneal mesothelioma (BMPM) is a rare tumor that occurs mainly in women in their reproductive age. The pathogenesis of BMPM is unclear and a controversy regarding its neoplastic and reactive nature exists.

The biological behavior of BMPM is characterized by its slowly progressive process and high rate of recurrence after surgical resection. In addition this lesion does not present a strong tendency to transform into malignancy. Today approximately 130 cases have been reported.

We here report a 62-year-old woman who had diffuse abdominal pain, nausea and vomiting. Physical examination revealed a painful mass in her upper abdomen. She reported a mild dehydration, but the vital signs were normal. Peristaltic rushes, gurgles and high-pitched tinkles were audible. Upright plain abdominal film revealed small bowel loops with air-fluid levels. She was diagnosed having an incarcerated incisional hernia that resulted in intestinal obstruction. The patient underwent surgery during which a cystic mass of the right ovary measuring 6 cm x 5 cm x 4 cm, four small cysts of the small bowel (1 cm in diameter) and a cyst at the retroperitoneum measuring 11 cm x 10 cm x 3 cm were found. Complete resection of the lesion was performed. The patient had an uneventful recovery and had no recurrence two years after surgery.

Benign cystic mesothelioma of the peritoneum: a clinicopathologic study of 17 cases and immunohistochemical analysis of estrogen and progesterone receptor status

Benign cystic mesothelioma (BCM) is an uncommon lesion of the peritoneum occurring predominantly in women of reproductive age. Although most patients are managed by surgical resection, a reported high incidence of cyst recurrence has led to the use of hormonal therapy in isolated cases in an attempt to control cyst size and relieve local symptoms. To date, the estrogen receptor (ER) and progesterone receptor (PR) status of BCM has not been evaluated. Here we present our experience with 17 cases (13 women, 4 men) of BCM seen over a 19-year period, including an immunohistochemical analysis of ER and PR status in 14 cases. All lesions showed typical morphological features of BCM, and calretinin immunostaining was positive in 14 of 14 cases. Five patients experienced either 1 or 2 tumor recurrences, and no patients died of disease. One case was diffusely positive for ER only, 1 case was focally positive for PR only, and 1 case was focally positive for both ER and PR. Although immunohistochemical detection of female sex hormone receptors in BCM is uncommon, the focal presence of ER and/or PR in some lesions does provide weak biologic support for the use of hormonal manipulation as a therapeutic option. Hum Pathol 34:369-374.

Video-assisted thoracoscopic excision of a benign cystic mesothelioma of pleura

We are reporting on the case of a 44-year-old woman upon which video-assisted thoracoscopic excision of a benign cystic mesothelioma of the pleura was performed. To our knowledge, this is the second report on a case of a benign cystic mesothelioma of the pleura. The cyst in our case was solitary and was easily excised. Microscopic examination revealed that the cyst was lined by a single layer of flattened and cuboidal cells. Immunohistochemical analysis revealed that the cells lining the cyst stained positively for keratin and negatively for factor VIII-related antigen. Benign cystic mesothelioma of the pleura was diagnosed based on histological findings. For seven months her condition has been monitored at our out-patient clinic with no signs of recurrence. However, continued careful observation is required because benign cystic mesothelioma often recurs locally. Local recurrence is thought to be related to incomplete resection of the tumor. Therefore, careful observations and techniques to ensure complete resection of the cyst, are important during video-assisted thoracoscopic surgery.

Peritoneal cystic mesothelioma treated with minimally invasive approach

A case of peritoneal cystic mesothelioma in a young woman was treated with a minimally invasive approach. The technique and a review of the literature are presented.

Pericardial multicystic proliferation

We report the case of an intrapericardial lesion with the pathological features of a multilocular cyst, found on the adventitia of an aortic aneurysm in a 62-yr-old man. Microscopically, it consisted of numerous cavities lined by flattened or cuboidal cells with the immunocytochemical and electron microscopical features of mesothelium, sometimes forming a hyperplastic pattern. Numerous nerve bundles and collections of inflammatory cells were present in the stroma. These features were consistent with a reactive lesion.

Multicystic mesothelial proliferation. Immunohistochemical, ultrastructural and DNA analysis of five cases

We investigated the clinicopathological findings in five cases of multicystic mesothelial proliferation (MMP). All masses consisted of multiloculated cysts attached to pelvic organs and sometimes growing into the upper abdominal cavity. The cystic spaces were lined by flattened or cuboidal cells. The stroma showed fibrosis, oedema and chronic inflammation. Immunohistochemistry revealed strong positive staining for cytokeratin and epithelial membrane antigen, and focal positivity for vimentin and carcinoembryonic antigen. The endothelial markers were negative. Electron microscopy showed abundant surface microvilli and well-developed basal lamina. DNA analysis identified euploid cell populations in all cases. All but one case had a previous history of abdominal surgery. Despite the worrying appearance the clinical outcome was favourable in all cases; there was one recurrence. Clinical and pathological data support the hypothesis that MMP represent a reactive mesothelial proliferation and not a neoplastic process.

Peritoneal benign cystic mesothelioma

A case of a benign cystic peritoneal mesothelioma is reported. A 25-year-old woman presented a 8-year history of recurrent tumor and five operations because of that. On the basis of this case and of 18 cases proved by electron microscopy reported by others, the clinicopathological features and the problems of differential diagnosis are discussed. The ultrastructural examination is essential for the diagnosis of cystic mesothelioma.

Serous surface carcinoma of the peritoneum: a clinicopathologic study of 22 cases

Serous surface carcinoma (SSC) of the peritoneum is defined as a primary tumor histologically indistinguishable from serous carcinoma of the ovary, diffusely involving the peritoneal surface but sparing or only superficially invading the ovaries. In this study of 22 cases of SSC, it was found that the main clinical manifestations of SSC were abdominal pain and enlargement. In most cases, SSC evenly involved the entire mesothelial surface but rarely was predominant in or even limited to the pelvis. It frequently invaded the submesothelium, but deep invasion into abdominal and pelvic organs or local metastasis was rare, and distant metastasis was not seen at presentation. Microscopically, SSC was a high-grade tumor frequently showing high mitotic rate, psammomas bodies, and necrosis. The tumor was usually contiguous with hyperplastic mesothelium on either ovarian surface or other locations. Tumor cells in all cases except one showed cytoplasmic or surface neutral or acidic mucin or both. Tumor cells stained positive for keratin (100% of cases), epithelial membrane antigen (100%), Leu-M1 (45%), B72.3 (85%), vimentin (35%), and carcinoembryonic antigen (25%). Electron microscopic studies of six cases showed epithelial differentiation in each. Seven patients (32%) were alive with no clinical disease at 3 to 31 months, one patient (4%) was alive with extensive local disease at 24 months, 11 patients (50%) died almost exclusively of local recurrence at 1 to 70 months, and three patients (14%) died of operative complications. It is concluded that SSC arises from peritoneal mesothelium but has epithelial phenotype. It can be morphologically differentiated from other conditions with similar laparotomy findings, such as malignant mesothelioma, benign papillary mesothelioma, cystic mesothelioma, and benign or borderline peritoneal serous tumors. The prognosis of SSC is poor, and most patients die of uncontrollable local disease.

Multilocular peritoneal inclusion cysts (so-called cystic mesotheliomas)

Twenty-five cases of multilocular peritoneal inclusion cysts (MPIC) were investigated. All but four cases were associated with a history of a previous abdominal or pelvic operation, or evidence of endometriosis or pelvic inflammatory disease, or combinations of these findings. All of the lesions were attached to pelvic organs, 44% also occupied the upper abdominal cavity, and 16% involved the retroperitoneum. In three cases free-floating cysts were present as well. The median diameter of the lesions was 13 cm. The cyst locules were lined by one to several layers of flat to cuboidal mesothelial cells that occasionally formed papillae, had a hobnail shape, or had undergone squamous metaplasia. The stroma was characterized by chronic inflammation and often acute inflammation. In most of the cases there was mural proliferation of the mesothelial cells, occasionally simulating a malignant mesothelioma. Twelve lesions were complicated by postoperative local recurrence; in four of these cases the recurrences were multiple; neither the size of the lesion nor the presence of mural mesothelial proliferation influenced the outcome. The clinical and pathologic data in this series suggest that the MPIC is a nonneoplastic reactive mesothelial proliferation.

Multicystic peritoneal mesothelioma: a case report

A case of recurrent cystic peritoneal mesothelioma is reported. Ultrastructurally the tumour cells showed abundant surface microvilli, desmosomes, intracytoplasmic filaments and well-developed basal lamina. The cells demonstrated positive staining for keratin peptides, vimentin and epithelial membrane antigen and, some of them, for carcinoembryonic antigen. No staining was demonstrable for a number of endothelial markers. The findings are in accord with the proposed mesothelial origin of the neoplasm and can be of help in the differential diagnosis of other multicystic neoplasms arising in the peritoneal cavity.

Benign cystic mesothelioma of the peritoneum: immunohistochemical and ultrastructural features in a child

Benign cystic mesothelioma of the peritoneum is a well-defined but rare entity. A total of 35 instances have been reported, almost all in adults, the majority females. Cystic mesotheliomas have, until recently, been labeled cystic lymphangiomas or lymphohemangiomas. We report the case of a 14-year-old boy who, despite only subtotal resection of his abdominal mass, is well and recurrence free 9 months after surgery. The role of immunohistochemistry and electron microscopy in diagnosis is emphasized.