Additional atypical malignant mesothelioma after intraperitoneal injection of mineral fibres in rats

Our plain-English summary of Additional atypical malignant mesothelioma after intraperitoneal injection of mineral fibres in rats, by K. Kamino, H. Ernst, U. Mohr (Experimental and Toxicologic Pathology, 1993).

The study

• Authors: K. Kamino, H. Ernst, U. Mohr
• Journal: Experimental and Toxicologic Pathology
• Published: 1993;45(2-3):65-6
• Type of article: Letter
• Read it: PubMed · Publisher

In plain English

This was a short letter to the editor, not a full study report. The authors described an unusual type of malignant mesothelioma in two rats from their own experiment, which used the same rat strain and treatment as an earlier report by Rittinghausen and colleagues. Besides atypical mesotheliomas with bone and cartilage features, they found this additional type. Two male Wistar rats injected into the abdominal cavity with 5 x 0.1 mg crocidolite developed a large, soft tumor. It covered the surface of the abdominal organs, the mesentery and the omentum. In many areas it was made of transparent vesicles filled with thick, glassy mucus. Under the microscope the tumor had solid areas and swollen or myxoid areas. Staining tests suggested the mucus was mainly hyaluronic acid. The authors noted that the extremely high hyaluronic acid production made the tumors look, to the naked eye, like mucus-producing adenocarcinomas. They stated that, to their knowledge, this type of malignant mesothelioma had not been reported in rats before. The letter does not say how many rats were treated, so it gives no tumor rate.

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: Letter to the editor describing two cases from an animal experiment (intraperitoneal injection in rats)
• Who was studied: Two male Wistar rats from the authors' own study, which used the same strain and treatment as an earlier study by Rittinghausen et al.; total number of animals treated not given
• Exposure: Intraperitoneal injection of crocidolite, 5 x 0.1 mg
• Main results:
  • In both rats, a greatly extended soft tumor covered the abdominal organs, mesentery and omentum majus, and in many areas consisted of numerous transparent vesicles filled with viscid glassy mucus
  • Under the microscope the tumor had solid areas with a mesenchymal appearance and edematous or myxoid areas; tumor cells contained mucopolysaccharides
  • The mucus stained strongly with alcian blue, and this staining was removed by prior treatment with hyaluronidase, suggesting hyaluronic acid was the predominant mucopolysaccharide
  • The authors considered the most remarkable point of the two cases to be the extremely high hyaluronic acid production, with vesicular or cystic formations that macroscopically resembled abundantly mucus-producing adenocarcinomas
  • This tumor type was found besides atypical mesotheliomas with osseous and cartilaginous differentiation in the same study
• The authors' conclusion: The authors stated that, to the best of their knowledge, this type of malignant mesothelioma had not previously been reported in rats

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma.

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)
• Mesothelioma dose response following intraperitoneal injection of mineral fibres — J.M. Davis, R.E. Bolton, et al. (1991)
• P53 mutations in tumours induced by intraperitoneal injection of crocidolite asbestos and benzo[a]pyrene in rats — K. Unfried, N. Kociok, et al. (1997)
• Differential diagnosis of malignant tumours in the abdominal cavity of rats after intraperitoneal injection of crocidolite or benzo[a]pyrene — J. Friemann, M. Varnai, et al. (1996)
• An assessment of the fibrogenic potential of two refractory fibres by intraperitoneal injection in rats — G.H. Pigott, J. Ishmael (1981)
• Giant cell formation after intraperitoneal application of crocidolite asbestos fibres in rats — S. Sethi, E.G. Beck, et al. (1974)

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