Ectopic breast tissue as a possible cause of false-positive axillary sentinel lymph node biopsies

Epithelial inclusions representing ectopic breast tissue are uncommonly seen in axillary lymph nodes. The extensive histopathologic examination of axillary sentinel lymph nodes of patients with breast carcinoma may increase the chances to encounter tiny foci of ectopic breast tissue, which may be mi...

Full description

Saved in:
Bibliographic Details
Published inThe American journal of surgical pathology Vol. 27; no. 4; p. 513
Main Authors Maiorano, Eugenio, Mazzarol, Giovanni M, Pruneri, Giancarlo, Mastropasqua, Mauro G, Zurrida, Stefano, Orvieto, Enrico, Viale, Giuseppe
Format Journal Article
LanguageEnglish
Published United States 01.04.2003
Subjects
Adult
Aged
Axilla - pathology
Breast
Breast Neoplasms - pathology
Choristoma - pathology
Diagnosis, Differential
False Positive Reactions
Female
Humans
Middle Aged
Sentinel Lymph Node Biopsy
Online AccessGet more information

Cover

More Information
Summary:Epithelial inclusions representing ectopic breast tissue are uncommonly seen in axillary lymph nodes. The extensive histopathologic examination of axillary sentinel lymph nodes of patients with breast carcinoma may increase the chances to encounter tiny foci of ectopic breast tissue, which may be misinterpreted as (micro)metastatic disease and lead to unwarranted completion of axillary dissection and to inaccurate staging and improper adjuvant treatments for the patients. Here we report on seven cases of ectopic breast tissue in axillary sentinel lymph nodes. In three cases there were coexistent micrometastases, and in the remaining cases the ectopic tissue was not associated with metastatic disease. The ectopic breast tissue showed remarkably varied morphologic features, including apocrine metaplasia and proliferative changes indistinguishable from those occurring in sclerosing adenosis and florid epithelial hyperplasia of the breast. A peripheral layer of myoepithelial cells was consistently detected in the ectopic glands and ducts. Besides awareness and purely morphologic criteria, a false-positive identification of these inclusions as metastatic carcinoma may be avoided by the use of immunohistochemical reactions for the localization of specific markers of the myoepithelial cell component, which is associated with the ectopic breast tissue.
ISSN:0147-5185
DOI:10.1097/00000478-200304000-00012