title: Absence of ectopic epithelial inclusions in 3,904 axillary lymph nodes examined in sentinel technique.
abstract: Intraoperative examination of sentinel axillary lymph nodes can be done by imprint cytology, frozen section, or, most recently, by PCR-based amplification of a cytokeratin signal. Using this technique, benign epithelial inclusions, representing mammary tissue displaced along the milk line, will likely generate a positive PCR signal and lead to a false-positive diagnosis of metastatic disease. To better appreciate the incidence of ectopic epithelial inclusions in axillary lymph nodes, we have performed an autopsy study, examining on 100 μm step sections 3,904 lymph nodes obtained from 160 axillary dissections in 80 patients. The median number of lymph nodes per axilla was 23 (15, 6, and 1 in levels 1, 2, and 3, respectively). A total of 30,450 hematoxylin-eosin stained slides were examined, as well as 8,825 slides immunostained with pan-cytokeratin antibodies. Despite this meticulous work-up, not a single epithelial inclusion was found in this study, suggesting that the incidence of such inclusions is much lower than the assumed 5% reported in the literature.
authors.affiliation: Department of Pathology, Johannes Gutenberg University, Medical School, Langenbeckstrasse 1, 55131 Mainz, Germany sonja.iken@kgu.de
authors.forename: Sonja
authors.initials: S
authors.lastname: Iken
authors.forename: Marcus
authors.initials: M
authors.lastname: Schmidt
authors.forename: Claudia
authors.initials: C
authors.lastname: Braun
authors.forename: Antonietta
authors.initials: A
authors.lastname: Valentino
authors.forename: Hans-Anton
authors.initials: HA
authors.lastname: Lehr
authors.forename: Stephan C
authors.initials: SC
authors.lastname: Schaefer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001365:Axilla; D015415:Biomarkers / Q000032:analysis; D004847:Epithelial Cells / Q000737:chemistry; D005260:Female; D005858:Germany; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000737:chemistry; D007633:Keratins / Q000032:analysis; D008198:Lymph Nodes / Q000737:chemistry / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy
chemical_list: D015415:Biomarkers; D007633:Keratins