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Histiocytoid breast carcinoma: Solid variant of invasive lobular carcinoma with decreased expression of both E‐cadherin and CD44 epithelial variant
Author(s) -
Fujiwara Masachika,
Horiguchi Miwa,
Mori Satoshi,
Yokoyama Koichi,
Horiguchi Hisashi,
Fukazawa Masakatsu,
Fujiwara Hiromi,
Yano Yukiko,
Satoh Hiroaki,
Kamma Hiroshi
Publication year - 2005
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/j.1440-1827.2005.01836.x
Subject(s) - pathology , invasive lobular carcinoma , cd44 , lobular carcinoma , cadherin , carcinoma , immunohistochemistry , breast carcinoma , biology , cytoplasm , epithelial cell adhesion molecule , cell adhesion molecule , medicine , breast cancer , cell , cancer , ductal carcinoma , immunology , invasive ductal carcinoma , biochemistry , genetics
Histiocytoid breast carcinoma (HBC) is a rare type of breast carcinoma with morphologic characteristics resembling those of histiocytes. Described herein are cytological and histological findings in a case of HBC. Fine‐needle aspiration cytology revealed numerous loosely cohesive tumor cells with abundant foamy to granular cytoplasm and bland‐appearing nuclei. The resected tumor exhibited a solid growth pattern instead of classic invasive lobular patterns observed in most reported cases of HBC. However, distinct intracytoplasmic lumina and Pagetoid extension to ducts suggested that this tumor was a variant of invasive lobular carcinoma. To determine the cause of the loose cellular cohesiveness of this HBC, its expression of the epithelium‐related cell adhesion molecules E‐cadherin and CD44v8‐10 (CD44 epithelial variant) was examined. Immunohistochemically, E‐cadherin was not detected, similar to most lobular carcinomas. Furthermore, competitive reverse transcription–polymerase chain reaction (RT‐PCR) analyses among alternatively spliced variants of CD44 revealed that the ratio of expression of CD44v8‐10 to that of CD44v10 (dominant variant in leukocytes) was lower than that for the reference breast carcinoma samples. It is concluded that the present case of HBC was a solid variant of invasive lobular carcinoma exhibiting foamy to granular cytoplasmic change. Decreased expression of both E‐cadherin and CD44 epithelial variant may be responsible for the loose cellular cohesiveness observed in HBC.