Ultrastructure of human mesotheliomas

Our plain-English summary of Ultrastructure of human mesotheliomas, by J.M. Davis (Journal of the National Cancer Institute, 1974).

The study

• Author: J.M. Davis
• Journal: Journal of the National Cancer Institute
• Published: 1974;52(6):1715-25
• Cited by: 71 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

An electron microscope study of 5 human biopsy specimens from suspected mesotheliomas showed that the tumor cell fine structure was usually similar to that of mesotheliomas produced in laboratory animals by the intraperitoneal injection of asbestos dust. In most instances, the tumor cells had a well-developed granular endoplasmic reticulum, and the cell cytoplasm often contained bundles of microfilaments. In some, these microfilaments made up a large part of the cell volume. Glycogen was found in all the neoplasms examined, and some had large amounts. Lipid granules, seen in the cytoplasm of many tumor cells, had a characteristic crenated surface. The cell surface membranes were characteristically modified to form numerous surface processes of variable type found usually around most of the cell circumference. The processes ranged from irregularly shaped microvilli to globular projections like miniature pseudopodia, and often these 2 forms were intermingled on the same cell. One biopsy specimen that did not conform to this general pattern was proved at autopsy to be a bronchial carcinoma with secondary spread into the pleural cavity. This indicated that electron microscope examination may be extremely useful as an aid to diagnosis when only small biopsy specimens are available.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

The author examined, by electron microscope, biopsy specimens from 5 patients with suspected mesotheliomas (4 pleural, 1 peritoneal) and compared them with mesotheliomas produced in laboratory animals by injecting asbestos into the abdominal cavity. One man had worked in the asbestos industry for 36 years. Two men reported no industrial asbestos exposure. Autopsy confirmed mesothelioma in 3 patients. Their tumor cells resembled the animal tumors. They had well-developed granular endoplasmic reticulum, bundles of microfilaments, glycogen, lipid granules with a crenated surface, and irregular microvilli mixed with globular surface projections. The fifth tumor looked like two of the mesotheliomas under the light microscope, but autopsy showed it was a bronchial carcinoma that had spread to the pleura. Its cells were closely packed, with few neatly interlocking processes and no glycogen or lipid granules. One patient was not autopsied, but the author judged this extremely likely to be an early mesothelioma. The author concluded that these features together, though none is conclusive alone, may help distinguish mesothelioma from secondary carcinoma in small biopsies.

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: Descriptive electron microscope study (small case series) of human biopsy specimens, compared with the author's earlier findings in asbestos-induced animal mesotheliomas
• Who was studied: 5 patients with suspected mesotheliomas (4 pleural, 1 peritoneal): a woman aged 55 and men aged 56, 56, 50 and 64. Biopsy specimens were supplied by surgeons at the London Hospital and King George's Hospital, Ilford, England. The study was done at the Institute of Occupational Medicine, Edinburgh. Dates of the biopsies are not stated.
• Exposure: Asbestos histories differed by patient; no fiber types were given for the patients. Patient 1 (woman) never worked at an asbestos factory, but relatives at the same address did for many years. Patient 2, a self-employed builder, had some contact with asbestos and lived 100 yards from an asbestos factory for 6 years. Patient 3 denied any industrial contact. Patient 4 worked in the asbestos industry for 36 years. Patient 5 had no history of industrial exposure.
• Main results:
  • Tumors in patients 2, 3 and 4 were confirmed as mesotheliomas at autopsy. Patients 2 and 3 had pleural tumors; patient 4 had a peritoneal tumor. Their fine structure was similar to animal mesotheliomas and to earlier reported human tumors.
  • In patients 2 and 3, tumor cell cytoplasm always contained well-developed granular endoplasmic reticulum, often with bundles of microfilaments. Crenated lipid granules and glycogen were also present.
  • Across the mesothelioma cells, microvilli and globular projections like miniature pseudopodia were often haphazardly intermingled on the same cell.
  • The cells of the peritoneal mesothelioma (patient 4) contained extremely large amounts of glycogen.
  • Patient 5's tumor, sent as a possible mesothelioma, was shown at autopsy to be a bronchial carcinoma with secondary growth in the pleural cavity. This could not have been diagnosed from light microscopy of the biopsy alone.
  • Patient 5's carcinoma cells differed in fine structure from the mesotheliomas. They were closely packed, with smooth membranes in contact over large areas, and no glycogen or lipid granules were found.
  • Patient 1's biopsy showed no definite neoplasia on histology, and no autopsy was done; the patient died 8 months after discharge. The cells resembled early animal mesotheliomas, and the author considered it extremely likely to be an early mesothelioma.
• The authors' conclusion: The author concluded that electron microscope examination may be extremely useful as an aid to diagnosis when only small biopsy specimens are available. The author added that the combination of features should be considered sufficient to assist greatly in distinguishing primary tumors of the body cavity linings from secondary carcinomas.
• Limitations the authors state:
  • Patient 1's diagnosis was not confirmed at autopsy.
  • No single feature is conclusive on its own, because each has also been reported in other tumor or cell types.
  • The author could not prove that glycogen-filled globules seen far from the cell body had become detached.

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: Mesothelioma, Biopsy, Neoplasm, Autopsy, Carcinoma, Pleural Cavity.

Related studies

• Acute and chronic effects of intraperitoneal injection of two types of asbestos in rats with a study of the histopathogenesis and ultrastructure of resulting mesotheliomas — M.L. Shin, H.I. Firminger (1973)
• The ultrastructure of asbestos bodies from human lung — J.M. Davis (1964)
• Histogenesis and fine structure of peritoneal tumors produced in animals by injections of asbestos — J.M. Davis (1974)
• Establishment and characterization of five human malignant mesothelioma cell lines derived from pleural effusions — L.S. Manning, D. Whitaker, et al. (1991)
• Further observations on the ultrastructure and chemistry of the formation of asbestos bodies — J.M. Davis (1970)
• The ultrastructure of asbestos bodies from guinea-pig lungs — J.M. Davis (1964)

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