Localized fibrous tumor of the serosal cavities. Immunohistochemical, electron-microscopic, and flow-cytometric DNA study

Our plain-English summary of Localized fibrous tumor of the serosal cavities. Immunohistochemical, electron-microscopic, and flow-cytometric DNA study, by A.K. el-Naggar, J.Y. Ro, A.G. Ayala, et al (American Journal of Clinical Pathology, 1989).

The study

• Authors: A.K. el-Naggar, J.Y. Ro, A.G. Ayala, R. Ward, N.G. Ordóñez
• Journal: American Journal of Clinical Pathology
• Published: 1989;92(5):561-5
• Cited by: 142 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Localized fibrous tumor of the serosal cavities (localized fibrous mesothelioma) is a generally benign spindle cell neoplasm of uncertain histogenesis. Fourteen histologically similar primary tumors from different mesothelium-lined sites (11 pleural and 1 each in the pericardium, peritoneal cavity, and pouch of Douglas) and 2 recurrences of those tumors (pericardium and pouch of Douglas) were examined histopathologically and by flow cytometry to relate histologic features and DNA ploidy to biologic behavior (follow-up, 48-255 months among 13 patients). All 16 tumors (14 primaries and 2 recurrences) displayed diploid DNA pattern, and none of 13 patients died of disease (1 patient was lost to follow-up). To elucidate the histogenesis, seven primary tumors were examined for vimentin and keratin immunostaining and six primary tumors were assessed by electron microscopy. All cases exhibited spindle-fibroblastic cell proliferation with a prominent hemangiopericytic pattern. All cases so examined had positive results for vimentin and negative results for keratin. Ultrastructurally, the tumor cells showed mesenchymal-fibroblastic features. These results support a mesenchymal origin, most likely from submesothelial fibroblasts. Further, this neoplasm may recur but retain its basic histologic features, diploidy, and benign outcome.

In plain English

This study described 14 patients with localized fibrous tumor of the serosal cavities (also called localized fibrous mesothelioma), a generally benign spindle cell tumor. Their tumors were accessioned at The University of Texas M. D. Anderson Cancer Center between 1959 and 1986. Eleven primary tumors arose in the pleura and one each in the pericardium, pouch of Douglas and peritoneum. The authors examined 14 primary tumors and 2 recurrences under the microscope and measured their DNA content by flow cytometry. All 16 tumors showed a diploid DNA pattern, which the authors said may suggest less aggressive behavior. All seven tumors stained for vimentin were positive for it and negative for keratin. All six examined by electron microscopy showed cells with mesenchymal features. Follow-up was available for 13 patients and lasted 48 to 255 months. Over that time two tumors recurred and there were no metastases. Eleven patients were alive and well, and two died of unrelated causes. The authors concluded that the results support a mesenchymal origin, most likely from submesothelial fibroblasts. They said more cases with longer follow-up are needed. The study did not examine asbestos exposure.

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: review of pathology material and patient charts, with immunohistochemistry, electron microscopy and flow-cytometric DNA analysis
• Who was studied: 14 patients (nine men, five women) with localized fibrous tumor of the serosal cavities: 14 primary tumors and 2 recurrences, accessioned at The University of Texas M. D. Anderson Cancer Center, Houston, between 1959 and 1986
• Exposure: Not studied. The article does not report whether these patients were exposed to asbestos. In the discussion, citing other work, the authors state that asbestos exposure has not been implicated in any reported cases.
• Main results:
  • Primary tumors were located in the pleura in 11 cases, and in the pericardium, pouch of Douglas and peritoneum in 1 case each
  • All 16 tumors (14 primaries and 2 recurrences) showed a diploid DNA pattern
  • The proliferative index (S-phase) was low: mean 2.0% in the primary tumors and 4.0% in the recurrences
  • All seven tumors examined immunohistochemically were positive for vimentin and negative for keratin
  • All six tumors examined by electron microscopy showed spindle cells with mesenchymal features
  • Where tumors were covered by mesothelial cells (three cases), there was no transition between mesothelial cells and tumor cells
  • Follow-up was available in 13 cases and ranged from 48 to 255 months (mean 144 months)
  • Two tumors recurred locally (pericardium and pouch of Douglas), at 120 and 156 months after surgery
  • There were no metastases. Eleven patients were alive and well at latest follow-up, and two died of unrelated causes
  • The authors interpreted the diploid DNA content in all primary and recurrent tumors as possibly suggesting less aggressive clinical behavior
• The authors' conclusion: The authors concluded that the findings support a mesenchymal origin of this tumor, most likely from submesothelial fibroblasts, and that it may recur but keep its basic histologic features, diploidy and benign outcome
• Limitations the authors state:
  • The authors state that more cases with prolonged follow-up are needed to support the observation that recurrent tumors keep a diploid DNA content

Topics

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

Medical terms in this study, explained in our Lexicon: Solitary Fibrous Tumor, Mesothelioma, Spindle Cell, Neoplasm, Mesothelium, Pericardium, Peritoneal Cavity, Fibroblast.

Related studies

• Solitary fibrous tumor of the pleura. An immunohistochemical, electron microscopic and tissue culture study of a tumor producing insulin-like growth factor I in a patient with hypoglycemia — E.H. Strøm, F. Skjørten, et al. (1991)
• Flow cytometric analysis of ploidy in immunohistochemically confirmed examples of malignant epithelial mesothelioma — H.F. Frierson, S.E. Mills, et al. (1988)
• Flow cytometric analysis of a localized malignant mesothelioma — J.J. Gómez-Román, R. Mons-Lera, et al. (2002)
• Peritoneal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients — I.K. Sienkowski, A.J. Russell, et al. (1986)
• Prognostic significance of flow cytometric DNA analysis in patients with malignant pleural mesothelioma — S. Emri, H. Akbulut, et al. (2001)
• Intrapulmonary localized fibrous tumor. Intraparenchymal so-called localized fibrous mesothelioma — S.A. Yousem, S.D. Flynn (1988)

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