Distinct Uroplakin II Staining Pattern in Apocrine Breast Carcinoma.
Appl Immunohistochem Mol Morphol 2022;
30:681-686. [PMID:
36227121 DOI:
10.1097/pai.0000000000001072]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 09/12/2022] [Indexed: 11/26/2022]
Abstract
Uroplakin II (UPII) has been shown as a highly specific marker of urothelial carcinoma; however, it can also stain subtypes of apocrine-differentiated breast carcinoma. Given that urothelium and breast epithelium share other common immunohistochemical markers, such as CK7 and GATA3, this can lead to a potential diagnostic pitfall. We stained a cohort of triple-negative breast cancer with UPII. Compared with the diffuse, cytoplasmic staining in urothelial carcinoma, UPII was positive in 38.9% of apocrine carcinoma (7/18) with a course, granular cytoplasmic staining pattern and negative in all nonapocrine triple-negative breast cancer cases. Furthermore, the same staining pattern was present in all apocrine metaplasia of the breast (4/4) and apocrine sweat glands in normal skin (6/6). This distinct subcellular localization of UPII staining in breast carcinoma can offer a potential solution to the above diagnostic pitfall.
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