Peritoneal Inclusion Cysts with Mural Mesothelial Proliferation
ABSTRACT The clinical and pathological features of six cases of a rare, hitherto unreported type of pelvic cyst are described. The cysts occurred in female patients (15-51 years of age) who presented with lower abdominal pain and evidence of a pelvic mass. All but one of the patients had a history of prior pelvic surgery. Laparotomy revealed dense pelvic adhesions and a cystic lesion that was interpreted by the surgeon as ovarian in origin. On gross examination, the cysts measured up to 15 cm in diameter, were uni- or multilocular and thin-walled, and contained bloody or serous fluid. They were adherent to the surface of the ovaries, but did not involve the ovarian parenchyma. On microscopic examination, the cyst walls were composed of markedly inflamed granulation and fibrous tissue in which were embedded mesothelial cells arranged in glands, nests, cords, and single cells. Because of this infiltrative pattern, as well as cytological atypia and mitotic activity within the mesothelial cells, a diagnosis of cancer was considered in several cases. All patients are alive with no evidence of disease at postoperative intervals of 6 months to 5 years. We propose that these cysts represent peritoneal inclusion cysts (benign cystic mesotheliomas) in which the histological appearance has been altered by an unusual degree of inflammation, fibrosis, and entrapment of mesothelial cells.
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ABSTRACT: 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.Tumori 95(6):808-10. · 1.09 Impact Factor
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ABSTRACT: A histologically-confirmed, multicystic, benign mesothelioma, with free-floating, thin-walled cysts, in the abdominal cavity of a 27-year-old woman was reported in 1954. After removal of all visible cysts by laparotomy, the patient was healthy and well for 29 years, when she was surgically treated for cholecystitis and gall bladder stones in 1982. The whole peritoneum was found covered with small cysts lined by mesothelial cells. The patient is (April 1987) well, with no complaints. Sections from the old paraffin blocks were studied by means of scanning, transmission electron microscopy and immunohistochemistry. These methods confirmed the histological diagnosis. The authors discuss whether such a lesion really is a benign tumor or should rather be otherwise classified.Apmis 12/1987; 96(1‐6):123 - 127. DOI:10.1111/j.1699-0463.1988.tb05278.x · 1.92 Impact Factor
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ABSTRACT: 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.Cancer 09/1989; 64(6):1336 - 1346. DOI:10.1002/1097-0142(19890915)64:6<1336::AID-CNCR2820640628>3.0.CO;2-X · 4.90 Impact Factor