Pseudomesotheliomatous carcinoma involving pleura and peritoneum: A clinicopathologic and immunohistochemical study of three cases

Our plain-English summary of Pseudomesotheliomatous carcinoma involving pleura and peritoneum: A clinicopathologic and immunohistochemical study of three cases, by I.A. Shah, J.R. Salvatore, T. Kummet, et al (Annals of Diagnostic Pathology, 1999).

The study

• Authors: I.A. Shah, J.R. Salvatore, T. Kummet, O.S. Gani, L.A. Wheeler
• Journal: Annals of Diagnostic Pathology
• Published: 1999;3(3):148-59
• Type of article: Case report
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Pseudomesotheliomatous carcinoma is a rare variant of peripheral adenocarcinoma of the lung that can manifest clinical, radiologic, and pathologic features similar to malignant mesothelioma. We present three patients with pseudomesotheliomatous carcinoma of the lung. In one patient the carcinoma extended beyond the thorax and extensively involved the peritoneum, mesentery, omentum, and intestines. All patients experienced weight loss and chest pain. All were white men aged 63, 65, and 67 years. Two were smokers and had shortness of breath, cough, and pleural effusion. One had a history of asbestos exposure. No patient developed dyspnea or hemoptysis. One was successfully treated for prostatic carcinoma 18 months earlier. Radiographically, all tumors were pleura-based. Grossly, the tumors spread extensively over pleural (and in one case peritoneal) surfaces and mimicked malignant mesothelioma. Histologically, all tumors were poorly differentiated and necrotic; two tumors exhibited spindle-cell components and desmoplasia. Mucin production was detectable in none, 10%, and 50% of tumor cells. The percentages of tumor cells immunoreactive for Ber-EP4 were 70%, 100%, and 80%; for Leu MI 0%, 90%, and 50%; for epithelial membrane antigen 80%, 80%, and 100%; for B 72.3%, 0%, 90%, and 20%; for polyclonal carcinoembryonic antigen 0%, 10%, and 10%; and for monoclonal 5%, 0%, and 0%. Of these, Ber-EP4 and B 72.3 rendered the most reliable diagnostic results. The clinical, radiologic, and gross and routine histologic findings were similar to those of a malignant mesothelioma; the final diagnosis could be made based mainly on immunocytochemical results. We have reviewed the English and German literature regarding 65 such tumors and present our experience with three additional cases. We emphasize the application of immunocytochemical studies on pleura-based poorly or undifferentiated malignant tumors of unknown origin.

In plain English

This article reported three cases of pseudomesotheliomatous carcinoma, a rare form of lung adenocarcinoma that can look like malignant mesothelioma, from the Veterans Affairs Medical Center in Phoenix, Arizona. The patients were white men aged 63, 65 and 67. The 65-year-old had a history of 30 years of asbestos exposure; the article does not name a fiber type. The other two had no known asbestos exposure, and no asbestos bodies were found in their lungs at autopsy. In all three, the tumor spread over the lining of the chest (pleura). In one man it also spread widely over the lining of the abdomen (peritoneum), resembling mesothelioma. Mucin stains marked none, 10% and 50% of tumor cells. The authors said that relying on mucin alone would have missed at least one third of the diagnoses. The marker Ber-EP4 stained 70%, 100% and 80% of tumor cells. The men died 7, 12 and 8 months after symptoms began. The authors concluded that the diagnosis rested mainly on immunostaining, with Ber-EP4 and B 72.3 giving the most reliable results.

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 (three case reports), compared with previously published cases
• Who was studied: Three white men aged 63, 65 and 67 years, treated at the Veterans Affairs Medical Center, Phoenix, Arizona; two were autopsied
• Exposure: One patient (Patient 3) had 30 years of asbestos exposure (fiber type and job not stated) and a 40 pack-year smoking history. Patients 1 and 2 had no known or reported asbestos exposure.
• Main results:
  • In Patient 2 the tumor covered the entire peritoneal surfaces as well as mainly the right side of the pleurae and the pericardium
  • No asbestos bodies or interstitial fibrosis were found in the lungs of the two autopsied patients without asbestos exposure (shown here for Patient 2; Patient 1's report says the same)
  • Mucin staining was positive in none, 10% and 50% of tumor cells in the three patients
  • The authors said relying on mucin alone would have missed at least one third of their diagnoses
  • Ber-EP4 stained 70%, 100% and 80% of tumor cells in the three patients
  • In Patient 3, CK-7 staining was positive and CK-20 staining negative, which the authors took as pointing to a lung origin
  • The three patients died 7, 12 and 8 months after symptoms began
• The authors' conclusion: The authors concluded that the diagnosis could be made mainly from immunostaining results, and that Ber-EP4 and B 72.3 gave the most reliable diagnostic results

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: Pseudomesotheliomatous Adenocarcinoma, Pleura, Peritoneum, Adenocarcinoma, Malignant Mesothelioma, Carcinoma, Thorax, Mesentery.

Related studies

• 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)
• 'Pseudomesotheliomatous' carcinomas of the pleura: a 10-year analysis of cases from the Environmental Lung Disease Research Group, Cardiff — R.L. Attanoos, A.R. Gibbs (2003)
• Expression of calretinin, thrombomodulin, keratin 5, and mesothelin in lung carcinomas of different types: an immunohistochemical analysis of 596 tumors in comparison with epithelioid mesotheliomas of the pleura — M. Miettinen, M. Sarlomo-Rikala (2003)
• Immunohistochemical analysis still has a limited role in the diagnosis of malignant mesothelioma. A study of thirteen antibodies — F. Roberts, C.M. Harper, et al. (2001)
• Pseudomesotheliomatous carcinoma of the pleura: an autopsy case of metastasis from a G-CSF-producing anaplastic carcinoma of the pancreas — Y. Hattori, K. Sentani, et al. (2018)
• A comparative immunohistochemical study of peritoneal and ovarian serous tumors, and mesotheliomas — N. Khoury, U. Raju, et al. (1990)

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