Malignant Peritoneal Mesothelioma in Women

Materials and Methods Of the cases, 60 were from the consultation files of two of us (P.B.C. and R.H.Y.) and 10 were from the files of Robert E. Scully, MD. The remaining cases were from the surgical pathology files of the Massachusetts General Hospital, Boston (2 cases); University of British Columbia, Vancouver (1 case); and the United States–Canadian Mesothelioma Panel (2 cases). Fifteen cases were published in a study of diffuse malignant epithelial mesotheliomas of the peritoneum in women,7 and 1 case was reported in a study of deciduoid Downloaded from https://academic.oup.com/ajcp/article/123/5/724/1759610 by guest on 13 December 2020 Am J Clin Pathol 2005;123:724-737 725 725 DOI: 10.1309/2H0NVRERPP2LJDUA 725 © American Society for Clinical Pathology Anatomic Pathology / ORIGINAL ARTICLE mesotheliomas.8 Cases from a previous study of 9 cases of malignant mesothelioma with prominent ovarian involvement were not included because the histopathologic features of these tumors were described in detail in that report.9 Tumors fulfilling our strict criteria for the diagnosis of well-differentiated papillary mesothelioma (see the “Discussion” section) were excluded. The number of H&E-stained sections available for review ranged from 1 to 31 (mean, 14). Mitotic counts were performed on 5 sets of 10 high-power fields (HPF), and the mitotic count in the highest set of 10 fields was recorded. Results Clinical and Operative Findings The patients were 17 to 92 years old (mean, 47.4 years). The clinical manifestations were known in 65 cases. Of these patients, 49 had abdominal or pelvic pain, abdominal swelling that in some cases was due to ascites, a pelvic mass, or combinations thereof. In 3 of these cases, a diagnosis of florid reactive or atypical mesothelial hyperplasia was made at initial operation, but laparotomy 2 months later (1 case), 3 years later (1 case), and at an unspecified interval for persistent symptoms (1 case) revealed malignant mesothelioma. In a fourth patient who initially had an acute bowel obstruction thought to be due to adhesions and was treated with a colostomy, a diagnosis of malignant mesothelioma was made on biopsy specimens obtained at the time of colostomy closure. In an additional case, a diagnosis of well-differentiated papillary mesothelioma was made on a tumor that at a subsequent operation 9 months later was shown to be malignant based on its infiltrative features. The tumor was an incidental intraoperative finding in 13 patients who underwent an operation for other reasons. One patient with a history of ovarian endometrioid carcinoma treated by surgery and chemotherapy had mesothelioma diagnosed at the time of “second-look surgery,” and in 1 patient initially given a diagnosis of stage III ovarian carcinoma that was treated with chemotherapy, subsequent reexploration and pathology review led to a change in diagnosis to malignant mesothelioma. In 1 case, the tumor was an autopsy finding. A history of asbestos exposure was given in 1 case, and 2 patients had received radiotherapy. At the time of laparotomy, widespread disease was identified in 59 cases. In many of these cases, the peritoneal surfaces were described as studded with tumor. In other cases, their appearance was less striking and characterized by terms such as granules, papillae, adhesions, or combinations thereof. The remaining cases lacked the diffuse distribution of disease seen in the cases just noted. In 3 of these cases, disease was limited to a segment of bowel: one of them was described as diffusely fibrotic with no evidence of a dominant mass, another as being fibrotic with numerous adhesions on the serosal surface and within the mesentery and adjacent omentum, and another as “bowel-to-bowel” adhesions forming a tumor-like mass. Disease limited to the omentum was found in 2 cases, and in an additional 2 cases, disease involving both ovaries and portions of the omentum was found. In another case, there was a 10-cm mass adjacent to the left ovary with focal disease involving 2 additional sites. In 3 cases, a single lesion was identified at the time of operation: a soft, red-tan, 4.0-cm right paratubal mass (1 case); a soft, tan-gray, 0.9-cm broad ligament mass (1 case); and a solid, tan, 2.2-cm nodule in the pelvic side wall (1 case). In the case found at autopsy, the abdominal and pelvic cavities were obliterated by tumor that encased the viscera. In 4 cases, the extent of the disease was unknown. Thirty-six patients were treated with a total abdominal hysterectomy and bilateral salpingo-oophorectomy, often with omentectomy and peritoneal biopsies that were accompanied by appendectomy (13 cases), bowel resection (3 cases), pelvic or para-aortic lymph node dissection (9 cases), liver biopsy (2 cases), or splenectomy (1 case). Three patients had a simple hysterectomy with peritoneal biopsies performed in 2 of them, and 1 patient had a total abdominal hysterectomy and unilateral salpingo-oophorectomy with biopsies. In 7 patients, bilateral salpingo-oophorectomy and multiple peritoneal biopsies were accompanied by an appendectomy (1 case) and a resection of bowel (1 case). In 1 case, a single mass was excised; in 1, a single nodule was biopsied; and in 1, only a segment of bowel was removed. In 15 cases, only peritoneal biopsies were performed. In 8 cases, the extent of the surgery was unknown, and in 1 case, as noted, the examination was postmortem