Microscopic loss of two-cell-pattern
厚生連医誌
was the golden
第１６巻
rule １号of carcinoma
１２８〜１of２９breast
２００７?

Brief Report

Microscopic loss of two-cell-pattern was the golden rule ofcarcinoma of breast ?
Nagaoka Central General Hospital, Department of Pathology ; Pathologist

Toshihiko Ikarashi
Through our present case of early carcinoma ofbreast, we revealed that our histological criteria of complete two-cell-pattern histology, consisted of both epithelial and basal myoepithelial cells, were regarded as benign
on the basis of the preservation of its normal two-cell-pattern configuration. This basal myoepithelial cells could beconfirmed by α-smooth muscle actin（α-SMA）reagent immunohistochemically. We should pay attention that thecomplete regular preservation of basal myoepithelial cells
was strongly suggested its benignancy and, conversely,
the complete loss of ones was also strongly suggested itsmalignancy. We also used our hitological golden rule toany organs having two-cell-patttern in normal counterparts, e.g. salivary gland, mammary gland, and prostate.

ductal hyperplasia diagnosed by Hematoxylin-Eosin（HE）stain（Fig.1）and ② atypical ductal hyperplasia :HE stain（Fig.3）．
Benign hyperplasia had regular basal cell layer
confirmed by immunostaining with α-SMA reagent（Fig.2）. We diagnosed the lesion of complete depletionof basal cells as malignancy（Fig.4），previously diagnosed
atypical hyperplasia on HE stain.
Although the strong stainability for c-erbB-2（Her-2）corresponded to its atypism and strongly suggested
malignancy, there was no available findings among otherimmunostaining results（Table 1.）. C-erbB-2（Her-2）wasinversely proportional to hormonal receptors, e.g. estrogen
receptor（ER）and progesterone receptor（PgR）.

Key Words : carcinoma of breast, two-cell-pattern, criteria, malignancy, α-SMA, α-smooth muscle actin,
immunostain

Conclusion
In genetic examination we could not reveal any p
53 genomic mutations by polymerase chain reaction-single
strand conformational polymorphism method（PCRSSCP）among borderline malignancies and early carcinomas of breast "．
Microscopically cell atypism was not enough to diagnose as malignancy, either.
Tissues with two-cell-pattern histology, consistedof both epithelial and basal myoepithelial cells, were regarded as benign on the basis of the preservation of its
normal two-cell-pattern configuration. This basal myoepithelial cells could easily confirmed by α-SMA reagent immunohistochemically. We should pay attention that thecomplete regular preservation of basal myoepithelial cells
was strongly suggested its benignancy and, conversely,
the complete loss of ones was also strongly suggested its
malignancy. But scattered irregular preservation of ones
could not support both its benignancy and its malignancy.
In routine pathological studies we used this hitologicalgolden rule to any organs having two-cell-patttern in normal counterparts, e.g. salivary gland, mammary gland, andprostate !．

Background
Microscopically atypism is one of the golden rulesof cancer. But many pathologists believed the histologicalstandard for cancer that the weaker atypism suggests malignancy. This added misunderstanding and confusion tocytological diagnosis based on atypism. We think it ismore accurate that cancer could not be neglected even if
atypism is weak and the atypism keeps its diagnostic importance in diagnosing malignancy.
On the other hand many pathologists also believed
the other microscopic standard of cancer that lost the twocell pattern, which loses basal myoepithelial cells from bilayer configuration consisted of superficial epithelial cells
and basal myoepithelial cells. This was also supported incytopathological diagnosis that the myoepithelial loss or
the pair cells suggested malignancy. Therefore, the loss of
two-cell pattern was regarded as the most reliable findingfor carcinoma of breast. In this paper we revealed our diagnosing standard of cancer regarding this disappearanceof the two-cell pattern in our case !．
CaseFemale patient aged 47 y/o was performed modified mastectomy. Pathological examination showed thefollowing findings : R, CD，5 x 5 x 1 cm, ductal hyperplasia with atypical ones, g, ly 0, v 0, stump（−），n（−）．Her histological findings were as followings：①References
１．Ikarashi T, Hasegawa H. Immunohistological identification of basal cells in a diagnosis of adenocarcinoma
of prostate : comparison of basal cell specific markers
between a high molecular weight cytokeratin（34 βE12）and a tumor suppressor gene product. Niigata-KenKoseiren Med J 2003；12：51-3.

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厚生連医誌

第１６巻

１号 １２８〜１２９ ２００７

２．Hidehiro Hasegawa, Toshihiko Ikarashi. Detection
analysis of the p 53 genomic mutations by PCR-SSCP
method. Niigata-Ken Koseiren Med J 2001；11：42-5.
和文抄録
小さな工夫
二相性の消失は乳癌の組織診断の黄金律
Microscopic loss of two-cell-pattern was the golden ruleof carcinoma of breast ?
長岡中央綜合病院、病理部；病理医
五十嵐俊彦

最近の早期乳癌症例を通して、我われの組織学的診断基準である上皮と α−平滑筋アクチン陽性の筋上皮による完全な二相性の保持が良性の根拠となることを示した。
逆に、二相性の完全な消失は悪性を示唆する。
しかしながら、不完全な消失は診断根拠とならない。
更に、この二相性の診断根拠は、他の唾液腺や前立腺の良悪性の診断にも応用される。
キーワード：乳癌、二相性、診断基準、悪性、α-SMA、
α−平滑筋アクチン、免疫染色

Table 1 Immunostaining result
Ab/lesionductal hyperplasia

atypica hyperplasia, regarded as intraductal carcinoma inthe present study

α-SMA

++

−

p５３−−

Ki−６７５−１０％

５−１０％

ER

++

++

PgR

++

++

c-erbB−２−−

Ab : antibody
SMA : smooth muscle actin
ER : estrogen receptor
PgR : progesterone receptor

Fig. 1Fig. 3Fig. 2

Fig. 4― 129 ―