An autopsy case of malignant mesothelioma associated with asbestosis

Our plain-English summary of An autopsy case of malignant mesothelioma associated with asbestosis, by M. Watanabe, N. Kimura, M. Kato, et al (Pathology International, 1994).

The study

• Authors: M. Watanabe, N. Kimura, M. Kato, D. Iwami, M. Takahashi, H. Nagura
• Journal: Pathology International
• Published: 1994;44(10-11):785-92
• Type of article: Case report
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

An autopsy case of malignant mesothelioma with asbestosis caused by asbestos exposure for 17 years is reported. Autopsy revealed that mesothelioma spread extensively in all serosal tissues including pleura, pericardium, diaphragm, peritoneum and tunica vaginalis testis. Histopathologically, most of the tumor showed an epithelial form, but sarcomatous and microcystic patterns were also observed. The tumor cells had abundant glycogen and hyaluronic acid and, immunohistochemically, they were positive for cytokeratin, vimentin and epithelial membrane antigen (EMA). Long, slender microvilli were characteristically observed in these tumor cells. All of these data were compatible with malignant mesothelioma. Procollagen type I (procol.l) immunostaining was performed to reveal the mesenchymal character of mesothelioma. Both epithelial-type cells and sarcomatous-type cells showed positive staining for procol.l, although the latter showed stronger immunoreactivity. Immunostaining for procol.l was found to be one of the useful tools for distinguishing mesothelioma from adenocarcinoma. Using an extraction method for asbestos fibers, asbestos bodies were found in many tissues including lymph nodes, liver, small intestine, spleen, kidney, testis and pleura, in addition to lung parenchyma. Although multiple tumor metastases from an undetermined primary site is not ruled out, 'multifocal tumorigenesis' is suspected from the widespread deposit of asbestos fibers.

In plain English

This Japanese case report described a 67-year-old man who sprayed asbestos-containing insulation products onto building walls and ceilings from 1972 to 1989. He had been diagnosed with asbestosis in 1987 and had smoked 20 cigarettes a day since age sixteen. He died in February 1993 and was autopsied. Malignant mesothelioma involved all serosal tissues: the pleura, pericardium, peritoneum and tunica vaginalis testis. Most of the tumor was of the epithelial type, with sarcomatous and microcystic areas. Tumor cells were positive for cytokeratin, vimentin and procollagen type I and negative for CEA. The authors considered procollagen type I staining useful for distinguishing mesothelioma from adenocarcinoma. Lung fibrosis was grade II. Asbestos bodies were recovered from every tissue examined and were most numerous in the lung parenchyma. The article does not name the fiber type. The authors wrote that a role for asbestos fibers was strongly suggested. Because no primary tumor site was found, they could not rule out spread from one site, but suspected the tumor arose in several places. The report describes one person.

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 report (single autopsy case)
• Who was studied: One 67-year-old man treated at Tohoku Rosai Hospital, Sendai, Japan. He was admitted in July 1992 and died on 25 February 1993. He had been diagnosed with asbestosis in 1987 and had smoked 20 cigarettes per day from age sixteen.
• Exposure: Occupational asbestos insulation work from 1972 to 1989, spraying asbestos-containing products onto walls and ceilings of buildings. The fiber type is not stated.
• Main results:
  • At autopsy, malignant mesothelioma involved all serosal tissues: pleura, pericardium, peritoneum and tunica vaginalis testis.
  • Most of the pleural tumor was of the epithelial type. Some parts showed a sarcomatous pattern, and a microcystic pattern was seen in the tunica vaginalis testis.
  • Tumor cells were positive for both cytokeratin and vimentin.
  • Tumor cells were negative for carcinoembryonic antigen (CEA) in all types.
  • Procollagen type I staining was positive in all tumor patterns and was stronger in the sarcomatous pattern than in the epithelial pattern. The authors considered it most useful for distinguishing mesothelioma from adenocarcinoma.
  • Under the electron microscope, tumor cells had numerous long, slender, occasionally branched microvilli.
  • Lung fibrosis (asbestosis) corresponded to grade II on the Craighead grading.
  • Asbestos bodies were found in all tissues examined after tissue digestion. They were numerous in the lung parenchyma. Spleen, kidney and pleura were graded 3+ (more than 20 per filter area). Small intestine and testis were graded 2+ (10 to 20). Pericardium, lymph nodes and liver were graded + (1 to 10).
  • The authors wrote that the numerous asbestos bodies strongly suggested that asbestos fibers took part in causing the mesothelioma.
• The authors' conclusion: The authors concluded that the numerous asbestos bodies, together with tumor at different stages (atypical reactive hyperplasia, mesothelioma in situ and advanced mesothelioma), may support 'multifocal tumorigenesis', meaning the tumor arising in several places, rather than spread from one site.
• Limitations the authors state:
  • Neither clinical examination nor autopsy could identify the primary site of the tumor.
  • The authors noted that metastases from an undetermined primary site were not ruled out.
  • The degree of lung fibrosis was less than the degree of respiratory function impairment.

Topics

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

Medical terms in this study, explained in our Lexicon: Autopsy, Malignant Mesothelioma, Asbestos Exposure, Mesothelioma, Pleura, Pericardium, Diaphragm, Peritoneum.

Related studies

• Evidence for an amphibole asbestos threshold exposure for asbestosis assessed by autopsy in South African asbestos miners — G.K. Sluis-Cremer, E. Hnizdo, et al. (1990)
• An autopsy case of a malignant pericardial mesothelioma in a Japanese young man — M. Watanabe, H. Suzuki, et al. (1999)
• Asbestos bodies in human lungs at autopsy — D. Cauna, R.S. Totten, et al. (1965)
• Asbestos fibers and pleural plaques in a general autopsy population — A. Churg (1982)
• Iron signature in asbestos-induced malignant pleural mesothelioma: A population-based autopsy study — S. Crovella, A.M. Bianco, et al. (2016)
• Relationship between number of asbestos bodies in autopsy lung and pleural plaques on chest X-ray film — T. Kishimoto, T. Ono, et al. (1989)

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