Well-differentiated papillary mesothelioma in the pelvic cavity. A case report

Our plain-English summary of Well-differentiated papillary mesothelioma in the pelvic cavity. A case report, by T. Haba, K. Wakasa, M. Sasaki (Acta Cytologica, 2003).

The study

• Authors: T. Haba, K. Wakasa, M. Sasaki
• Journal: Acta Cytologica
• Published: 2003;47(1):88-92
• Type of article: Case report
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Well-differentiated papillary mesothelioma (WDPM) is considered to be a distinct subtype of peritoneal mesothelioma. It occurs in the peritoneum, is most commonly seen in young women and is found incidentally at laparotomy for other indications. Clinically, WDPM is considered to be benign or to have low malignancy potential.

Case: A 48-year-old female with no history of asbestos exposure presented with hypermenorrhea. An operation was performed for adenomyosis, and six papillary nodules, 2 cm or less, were found in the serosa of the pelvic cavity. Peritoneal lavage fluid and imprint material from the tumor were obtained for cytologic examination. The cytologic specimens showed many scattered cells and sheetlike clusters and some papillary clusters. These cells had abundant, polygonal, cyanophilic cytoplasm; clearly outlined borders; and slitlike intercellular spaces. The cell arrangement was orderly. The nuclei were uniform in size, with a single centrally located nucleolus, and there were no binucleated forms or mitosis. There was no increase in chromatin. On the luminal surface of the cells, a brush border was observed.

Conclusion: It is important to differentiate WDPM from diffuse malignant mesothelioma or other peritoneal malignant tumors to avoid treating them as malignant tumors.

In plain English

This was a case report from Osaka City University Hospital in Japan. It described one woman with well-differentiated papillary mesothelioma (WDPM), a subtype of peritoneal mesothelioma (mesothelioma of the lining of the abdomen). The authors noted that WDPM is considered benign or of low malignant potential. The patient was a 48-year-old elementary school teacher who had heavy menstrual bleeding (hypermenorrhea) and no history of occupational asbestos exposure. During the operation, surgeons noted uterine adenomyosis and a 7 cm hemorrhagic cyst in the right ovary, which pathology later showed was an endometrial cyst. They also found six papillary nodules, 2 cm or less, on the lining of the left ovary, appendix, uterus and broad ligament of the uterus. Cells from abdominal washings and tumor imprints were orderly and uniform, with no dividing cells seen. Tissue stains were positive for keratin, calretinin and thrombomodulin and negative for vimentin, and the diagnosis of WDPM was confirmed. The authors concluded that it is important to describe these tumors correctly in pathology reports, and to tell them apart from malignant tumors, to prevent overtreatment.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (single patient)
• Who was studied: one 48-year-old woman (gravida 2, para 2), an elementary school teacher, treated at Osaka City University Hospital, Japan; article received for publication November 2001
• Exposure: No asbestos exposure. The patient was an elementary school teacher. The article body says she had no history of occupational asbestos exposure, and the printed abstract says no history of asbestos exposure.
• Main results:
  • At operation, adenomyosis was detected in the uterus and a hemorrhagic cyst, 7 cm in diameter, was noted in the right ovary
  • At operation, six papillary nodules of 2 cm or less were found on the serosa (lining) of the left ovary, appendix, uterus and broad ligament of the uterus
  • On later pathologic examination, the right ovarian mass was an endometrial cyst, and the patient had uterine adenomyosis
  • In the cytology specimens (peritoneal washings and tumor imprints), the cells were arranged in an orderly way, with no binucleated cells and no mitosis (cell division)
  • Under the microscope, the tumors were lined by a single layer of uniform cuboidal cells, and tumor invasion into the ovary and uterus was slight
  • On immunohistochemical staining, the lining cells were strongly positive for keratin, calretinin and thrombomodulin
  • The tumor cells were negative for vimentin
  • Based on the cytologic and pathologic findings, the diagnosis of WDPM was confirmed
• The authors' conclusion: The authors concluded that WDPM should be correctly described in the pathology report, distinguishing it from diffuse malignant mesothelioma and other malignant peritoneal tumors, in order to prevent overtreatment

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Well-Differentiated Papillary Mesothelioma, Peritoneal Mesothelioma, Peritoneum, Laparotomy, Asbestos Exposure, Malignant Mesothelioma.

Related studies

• An incidental diagnosis of well-differentiated papillary mesothelioma in a woman operated on for recurrent endometriosis — R. Mangal, O. Taskin, et al. (1995)
• Well-differentiated papillary mesothelioma of the female peritoneum: a clinicopathologic study of 26 cases — A. Malpica, S. Sant'Ambrogio, et al. (2012)
• Therapeutic strategies for well-differentiated papillary mesothelioma of the peritoneum — Y.K. Lee, H.J. Jun, et al. (2013)
• Value of mesothelial and epithelial antibodies in distinguishing diffuse peritoneal mesothelioma in females from serous papillary carcinoma of the ovary and peritoneum — R.L. Attanoos, R. Webb, et al. (2002)
• Aberrant Pax-8 expression in well-differentiated papillary mesothelioma and malignant mesothelioma of the peritoneum: a clinicopathologic study — D. Xing, N. Banet, et al. (2018)
• Well-differentiated papillary mesothelioma — K.J. Butnor, T.A. Sporn, et al. (2001)

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