厚生連医誌

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１号 １００〜１０４ ２００４

Original Article

Confirmation of asbestos body by both a usual optic microscopy and an electron probe micro―analysis（EPMA）―three autopsied cancer cases of pulmonary asbestosis―
Department of Pathology, Pathology Center ; Pathologist

Toshihiko Ikarashi

Abstract
Background : Most simple and definitive diagnosis ofasbestosis was established by light microscopic examina，and EPMA wastion with Hematoxylin―Eosin stain（HE）
regarded as one of the supplemental diagnostic methods.
Our four cases of occupational pneumoconiosis were examined with microscopy and EPMA, and its effectivenessfor diagnosis was discussed in this report. Cases : Threecases among these four occupational pneumoconiosis hadmalignancies : adenocarcinoma of lung, small cell carcinoma of lung, and diffuse mesothelioma. Formalin―fixedparaffin―embedded pulmonary specimens were searched
for a presence of asbestos body by light microscopy andanalyzed for physical constitutions of deposits. Two cases
were diagnosed by both an occupational history and an
EPMA analysis. The other two cases were amphibole asbestosis. Discussion : Asbestosis was microscopically confirmed in two constructional workers and also electron―
microscopically in one brake―lining maker. EPMA wasvery valuable for a physical confirmation of asbestos
character. Even if a use of asbestos becomes severely
regulated legally, a lot of asbestosis or its complications
are expected to occur as illness on―the―job for the next
４０―５０ years, and a detailed occupational history andclearer diagnostic methods as EPMA will be demanded.
Key Words : occupational exposure, X―ray microanalyzer, electron probe micro―analysis（EPMA），serpentine,amphibole, asbestosis, asbestos body

Background
Asbestos is superior in both a nonflammability and aplasticity and three types of asbestos are widely used inindustries as a commercial asbestos ; e.g. chrysotile, crocidolite, and amosite（Fig．
１）．An on―the―job accident related to asbestos exposure has been legally regulated according to both the second number and the seventh one in
Table１―２related to Article３５ of the Constitution in Enforcement Regulations of Labor Standards Law from １９４８in Japan. A consumption of asbestos has been legally restricted and reduced after １９９０s because asbestos induces

asbestosis and other complications. Pathological or autopsied confirmation of occupational exposure of asbestos became very important to rescue the asbestosis―related patients.
Asbestos fibers consist mainly of silicon, iron, andmagnesium and are classified into ６ materials（Fig．
２）
（１―３）
．
It was suggested that an occupational exposure of asbestos induced several diseases, classified based on an exposure condition as follows：（i）an exposure of both high―dose and short―duration less than ２０ years induced pulmonary asbestosis, beginning from lower lobes，（ii）bothhigh―dose and long―duration between ２０ and ４０ years
０％ of asbestosis withcaused carcinoma of lung in １
０―２
５ times risk rate by smoking，（iii）both low―dose andshort―duration raised pleural plaque regardless of occupation or non―occupation，（iv）diffuse pleural thickening，
０ years induced benign asbestos（v）long―duration of ３
pleural effusion or pleuritis, and（iv）either a low―dose and０―years―latent
long―duration from ２０ to ４０ years or a ４phase with ２０―years―exposure induced diffuse malignant
mesothelioma in pleura（８０％ in whole cases with mesothelioma），peritoneum, pericardium, and testicular vaginal．In the Workmen's Compenperitoneum
（Fig．
３）
（１―３）
sation Law, a pathological decision of pneumoconiosis
with an occupational history was very important for an
identification of on―the―job disease.
As to asbestosis, counting asbestos number was also
useful as well as an existence of asbestos body because its
number also corresponded to a possibility of its exposure
（Fig．
４）
（１―３）
．
We experienced four autopsied cases suggested as occupational pneumoconiosis and reported in this article. Asbestosis was analyzed by both a usual optic microscopy
and an EPMA, and their utility was discussed（１―４）．

Cases
Four pneumoconiosis cases were listed with occupational histories, complications of cancer, light microscopic
findings, EPMA analyses, and estimations of exposurematerials（Fig．
６）．Examined specimens from lungs con-― 100 ―厚生連医誌

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１号 １００〜１０４ ２００４

sisted of one or six tissues a pulmonary lobe, each one ofwhich was at least accompanied with charcoal deposition
and fibrosis.
In the first case an asbestoid body confirmed microscopically was regarded as an iron―related deposit, nottrue asbestos body, because there was no silicon elementin spite of much content of iron in EPMA analysis. Other
occupationally suspicious materials, carbonized silicon andaluminum oxide, were also confirmed by EPMA analysis.
４ years, noIn the second case making brake―lining for ３
asbestos could be confirmed in routine microscopic examination, but EPMA revealed much magnesium as wellas silicon. Both much deposition of magnesium and an
occupational history of brake―lining rich of asbestos suggested asbestosis. Asbestosis was induced by chrysotile
asbestos because there was much magnesium in EPMA
analysis and a microscopic absence of asbestos wasthought to its soluble tendency in acid―sided fixative offromalin（Fig．
２，６）．The third and the fourth cases wereconstructional workers. Asbestos body was derived fromamphibole asbestos because it richly contained of bothsilicon and iron with a very small amount of magnesium
（Fig．
２，６）．
Asbestos bodies were mainly found in lower pulmonary
fields with anthracosis. There was no tendency between
the number of asbestos bodies and the pleural predominance or scar formations.

Discussion
Asbestos was reported as a inducer of carcinoma of．
lung and mesothelioma as well as asbestosis（１―３）
The onset frequency correlated to not only its exposing
dosage but also its exposing duration or smorking（１―３）．
As to the routine microscopic analysis with HE stain
for a confirmation of asbestos body in lungs, it was reported that the density of asbestos body in malignancy―
complicated cases was slightly more than that in control
asbestosis ones without malignancies. On the basis of theexposing degree, malignancy―complicated cases was classified into no asbestos body（１％）
，low density（７３％），moderate density defined by ０．
５―２ asbestos body fibers/
cm２ of specimen area（１４％），and high density（１２％）!．On the other hand, control malignancy―uncomplicatedcases consisted of no asbestos body（３％），low density（８５％），moderate density（９％），and high density（３％）!．These results required intensely microscopical analysis because any microscopic glass contained only
few asbestos bodies and, furthermore, asbestos body ofserpentine type was dissoluble in formalin fixative anddisappeared. On searching asbestos body anthracosis andfibrotic foci became a hallmark in this study.
Asbestos body consisted mainly of silicon, iron, andmagnesium. Furthermore, asbestos was differentiated into
serpentine―type and amphibole―type based on a ratio ofmagnesium to iron. When a confirmation was very difficult in this study, physical analysis by EPMA was regarded as more suitable for the physical constitutional

analysis of pulmonary deposits"．
Acknowledgement :I thank Hiroshi Kobayashi, a pathologist in Hamamatsu
Seirei General Hospital and one of the most famous specialists in asbestos, for his advice as follows : asbestosis
could be diagnosed only by routine light microscopic
analysis in formalin―fixed paraffin―embedded HE stained
sections if specimens could be sampled from anthracotic
or fibrotic areas in lower lobes of lungs. But asbestos
body used to be too small and various in shape microscopically, this brown―magic―stick―mimetic body may beeasily overlooked with a poor attention. An additional microscopic examination after a few days will bring you
around the magic stick.
I thank Masayoshi Kobayashi, the technologist in Roomof EPMA（Electron Probe Micro―Analysis）analysis inCenter for Instrumental Analysis Niigata University, for
his physical analysis.

References
１．Industrial medicine and occupational diseases. In :Ikarashi's medical ABC understandable even by a cat―Clinicopathological mechanism and its medical
３８th ed. Nagaoka : Pimentostrategy―．Ikarashi T. ed．
Press；２００３（３５．
９GB of content）（Soft : Windows.
Exel,PowerPoint（Microsoft），Photoshop（Adobe），Ichitaroh（Justsystem），and DocuWorks Desk（FujiXerox））．
２．Kitagawa M, Murai Y. Pathological findings of asbestos―related diseases. Byo―to―Rin １９８９；７：７０２―８．
（in Japanese）In : A special number on the pollution of asbestos and its related diseases. eds.
Masamichi Sasaki, Masanobu Kitagawa. Byo―to―Rin３０（．in Japanese）
１９８９；７：６７５―７
３．A study meeting report about an authorization standard of the illness in workers exposed to asbestos.
ed. A study meeting of an authorization standard ofthe illness in workers exposed to asbestos．
２００３．
http : //www.mhlw.go.jp/shingi／２００３／０８／s０８２
６―４．
html#mokuji（in Japanese）
４．EPMA（Electron Probe Micro―Analysis）in Center for
Instrumental Analysis Niigata University. http : //www.dent.niigata―u.ac.jp/epma/index―j.html（in Japanese, A request for analysis and its details）

和 文 抄

録

原著
通常光学顕微鏡検査と Electron Probe Micro―Analysis（EPMA）によるアスベスト体の確認―肺石綿症の３担癌剖検例―病理学センター、病理科；病理医
五十嵐俊彦― 101 ―

Confirmation of asbestos body by both a usual optic microscopy and an electron probe micro―analysis（EPMA）―three autopsied cases of pulmonary asbestosis―

要約
背景：アスベスト（石綿）が石綿症、肺癌および中皮腫を誘発するので、アスベストの消費は法的に規制され、１９９０年代よりその輸入量は激減してきた。アス
ベストの職業的な曝露に関する病理学的または解剖学的確証は、石綿症関連の業務上の疾患症例の労災判定の為に非常に重要である。大部分の症例における最も簡単で決定的な診断手法は通常の光学顕微鏡検査によって確立され、そして、EPMA は補助的な診断法の１つであろう。症例報告：今回検討された職業性塵肺の４症例において、３例は悪性腫瘍（肺腺癌、小細胞性肺癌、瀰漫性胸膜中皮腫）を合併していた。ホルマリン固定パラフィン包埋肺組織の顕微鏡検査によるアスベスト小体の存在が検索され、また、沈着物の物理学的構成成分が分析された。２症例は職歴と EPMA分析によって診断された。残りの２症例は角閃石系石綿症であった。考察：石綿症は、顕微鏡学的に２人の建築関係労働者で確認され、その上、EMPA により１人のブレーキライニ ン グ 製 造 者 で 推 定 さ れ た。
EPMA は、アスベストの物理学的成分分析上、非常に有効であった。たとえアスベスト使用が法的に厳格に管理されるとしても、多くの石綿症とその合併症が０年の間に発症することが予測され、労災認
今後４０―５
定上、詳細な職業上の曝露の確認と EPMA 分析が重要となるであろう。
キーワード：業務上の疾病、X 線マイクロアナライ
ザー（EPMA）、蛇紋石、角閃石、石綿症、アスベスト小体

Fig１．Using list of asbestos products
kinds of productsbuilding materials

usage
pushed−out molding cement board outer wall, partitioning wall
slate for Making−up roof

substitution

legal control

possible

prohibited

impossibility

restricted, managed

maked−up slate−covered roof

cement board reinforced with fibers roof, outer wallnon−building materials

siding in ceramics

decoration

asbestos cement cylinder

chimneyglue

building materials, industrial productfriction materials

clutch−lining, clutch−facing, brake−pad, brake−lining

heat resistance, electric insulation board switchboard
joint−sheet

plumbing gasket

sheeling materials

filler for leak prevention of machinery joint

industrial product materials

asbestos cloth

Fig２．Characteristics of asbestos fibers

asbestos namefamilyideal
for- chief ingre- ubsidiary in- acid−resist- heat − resis- consumption oncogenesis in １
９９５
muladientsgredients
nacetant（℃）
Mg３ Si２chrysotile
solublein
５５０−７０
０ ９０％ ＜Si, Mg（white asbes- O ５
formalin（OH）４tos）
Na２（Mg<< Fe ２ ＋ ）３ Fe３＋ Si, Fe, NacrocidoliteMg
resistant
４００−６００ ＋＋prohibited
２ Si ８（blue a．
）
O ２２（OH）２（Mg<Fe２＋）７ Si Si, Fe
amositeMg
resistant
６００−８００ ＋
prohibited２（brown a．） ８ O２（OH）２（Mg>Fe２＋）７ Si
anthophylite
８ O２２（OH）２Ca２ （Mg>>Fe２＋）
５ Si ８tremolite
O ２２（OH）２Ca２ （Mg< Fe ２ ＋ ）５ Si ８actinolite
O ２２（OH）２

serpentine

amphibole

constitutional

charcteristics

legal control by thecabinet order of Industrial Safety and HealthLawmineralogy― 102 ―

in ２００４
restricted

restricted

restricted

restricted厚生連医誌

第１３巻

１号 １００〜１０４ ２００４

Fig３．Vulnerable diseases on the basis of a relation between
a dose and a duration of occupational asbestos exposure
doseduration
short（＜２０ years）

long（２０−４０ years）

highasbestosis

carcinoma of lung

low

pleural thickening

mesothelioma

Fig４．Diagnostic standards presented in an official notice（＃０９１９００１）by the chief of Labour Standards Bureau,
Ministry of Health, Labour and Welfare, on Sep１
９th, in２００３．
diseasescriteria for workmen's compensation
pneumoconiosis of the ４th. stage in management classification or withany other complications! or "，with occupational exposure for１０years or more

pulmonary asbestosis
carcinoma of lung! pneumoconiosis on chest roentgenogram" pleural plaque or asbestos bodymesothelioma（pleural, peritoneal, testicular vaginal! or "，with occupational exposure for １year or more
! pneumoconiosis on chest roentgenogram" pleural plaque or asbestos bodypleural thickening

related to asbestosis with marked respiratory disturbancestage of management : based on Article ４ in Pneumoconiosis Law

Fig５．Evaluation of an asbestos exposure level based on a asbestos body concentration in the pulmonary
tissueexposure levels

ABAB/cm２ in HE

ABx１
０E＋３／g（dried weight）

common inhabitant＜１＜１occupational exposure, possible

１−２

１−５

occupational exposure, probable２＜５＜

１
０E＋３：x１
０００
AB : number of asbestos bodies― 103 ―

Confirmation of asbestos body by both a usual optic microscopy and an electron probe micro―analysis（EPMA）―three autopsied cases of pulmonary asbestosis―

Fig６．Summary of our autopsied cases
case numberautopsy
numberageoccupationcase １case ２case ３case ４SN９９−００
９SN０２−００３SN０２−０１３SN０２−０２６grind（carbonized silicon,iron oxide, aluminumoxide）

５３６９７８brake−lining（car building disman- wall−blowing
availabilityof tling, construction
traffic
facilities
part, during ３４years）

occupational
diseasespneumoconiosisofthe ４th. stage inmanagement classification

adenocarcinoma mesothelioma of small cell carciof lung, pneumo- pleura, pneumo- noma of lung ,coniosis （ pleural coniosis （ pleural pneumoconiosis（pleural thickenthickening）
thickening）
ing）

５７

Hematoxylin − asbestoid
Eosn stain（＃／cm２）０．
１

０００

upper field（numbers/cm２）

００

０．
３

０．
２

lower field（numbers/cm２）

０

０

１．
８

２．
２

specific areas

subpleural %

０００

１
９

asscociated lesions

scar %

００

５０

１
５

７５

９６

asbestos

anthracosis %EPMA analysis constitution %

Si

１０００

++

Fe

++

Mg
Al

++

CaK＋

６１

３４＋

２
３

４０

++

１１−

１
３

６．
６

++
＋

４．
３

４

２．
４

８．
８

Cr

２．
３

S

１．
３

１．
１

Ti
P

２．
３＋

２．
２

Cl
estimation

０．
３SiC

FexOy

― 104 ―

Al２O３ serpentine

amphiboleamphibole