Benign mesothelial proliferation with effusion. Clinicopathologic entity that may mimic malignancy

Our plain-English summary of Benign mesothelial proliferation with effusion. Clinicopathologic entity that may mimic malignancy, by R.M. Hansen, J.G. Caya, L.J. Clowry, et al (The American Journal of Medicine, 1984).

The study

• Authors: R.M. Hansen, J.G. Caya, L.J. Clowry, T. Anderson
• Journal: The American Journal of Medicine
• Published: 1984;77(5):887-92
• Type of article: Case report
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The clinical and pathologic features of five cases of a previously poorly defined syndrome, benign mesothelial proliferation with effusion, are described. Although this is a benign process, both the gross and the microscopic findings may mimic metastatic papillary adenocarcinoma. Three of five patients had dysynchronous involvement in more than one body cavity developing over intervals of one, two, and six years. The clinical course is unpredictable and is usually associated with a good prognosis, but two of three patients with pericardial involvement required pericardectomy for pericardial tamponade. The entity of benign mesothelial proliferation with effusion and its distinction from true malignant conditions are discussed.

In plain English

This case series described five patients with what the authors called benign mesothelial proliferation with effusion. Here the cells lining body cavities grow without becoming cancerous, and fluid builds up. Fluid gathered around the lungs or heart or in the abdominal cavity (ascites), usually an exudate high in protein and lactic dehydrogenase. Under the microscope the cells looked uniform and benign, yet two patients were first suspected of metastatic papillary carcinoma. Three patients had two body cavities affected at different times, one, two and six years apart. Two of the three with fluid around the heart needed pericardectomy for tamponade. Two patients were alive 12 and 14 years after diagnosis; one died of lymphoma. Patient 1 still had a chronic pleural effusion. Patient 2's case report said she stayed free of fluid, though the discussion described both as having intermittent effusions. The authors concluded that, given the excellent prognosis with conservative treatment, the condition must be told apart from cancer. The article did not report asbestos exposure; citing Goepel, the authors wrote asbestos does not appear to play a role in benign proliferation.

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 series (five case reports with review of medical records and cytologic and histologic specimens)
• Who was studied: Five patients, one man and four women aged 36 to 61, reported by authors at the Medical College of Wisconsin, Milwaukee. Effusions or related disease were first noted between 1970 and 1976.
• Exposure: Asbestos exposure was not studied, and the article does not report the patients' exposure histories. In the discussion the authors cited an earlier report by Goepel stating that asbestos does not appear to play a role in benign proliferation.
• Main results:
  • Every patient had ascites, pleural effusion and/or pericardial effusion. The fluid was usually an exudate with high total protein and high lactic dehydrogenase levels.
  • Three of the five patients had involvement of two body cavities at different times. The intervals between detection in separate cavities were one, two and six years.
  • Two of the three patients with pericardial involvement required pericardectomy for pericardial tamponade.
  • Two patients (Patients 1 and 2) were initially suspected of having metastatic papillary carcinoma.
  • In effusion specimens, the nuclei of the mesothelial cells were extremely uniform in size, shape and staining, which suggested a benign lesion.
  • Patient 1 remained clinically well with a chronic pleural effusion more than 12 years after initial diagnosis.
  • According to the case report, Patient 2 remained free of pleural or peritoneal fluid accumulations for more than 14 years after her original pleural effusion. The discussion instead describes Patients 1 and 2 as alive with intermittent effusions.
  • Patient 3, who also had malignant lymphoma, died of progressive abdominal lymphoma.
  • Three patients had previously documented tuberculosis but no evidence of active tuberculosis at the time of mesothelial proliferation. The authors raised the question of whether tuberculosis may be a predisposing factor.
• The authors' conclusion: The authors concluded that, because of the excellent prognosis with conservative therapy, benign mesothelial proliferation with effusion must be recognized and differentiated from true papillary carcinoma and other malignancies.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Adenocarcinoma, Prognosis, Pericardial.

Related studies

• The role of liquid-based cytology and ancillary techniques in pleural and pericardic effusions: an institutional experience — E.D. Rossi, T. Bizzarro, et al. (2015)
• Pericardial mesothelioma masquerading as a benign pericardial effusion — N.L. Coplan, A.J. Kennish, et al. (1984)
• Asbestos pleural effusion: a clinical entity — G. Mårtensson, S. Hagberg, et al. (1987)
• Diagnostic usefulness of tumour marker levels in pleural effusions of malignant and benign origin — F. Kuralay, Z. Tokgöz, et al. (2000)
• Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist — T. Kishimoto, N. Fujimoto, et al. (2020)
• Benign asbestos pleural effusion associated with pulmonary aspergilloma — J. Hiyama, M. Marukawa, et al. (1998)

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