title: A subset of nondescript axillary lymph node inclusions have the immunophenotype of endosalpingiosis.
abstract: We report 2 cases of bland, otherwise nondescript axillary lymph node inclusions that have the immunophenotype of endosalpingiosis in patients with concurrent invasive breast carcinomas. Neither inclusion demonstrated the classic morphology of endosalpingiosis with admixed ciliated and secretory cells. Rather, both cases were composed of nondescript cuboidal to columnar bland epithelial cells situated within the lymph node capsule. Whereas both inclusions labeled diffusely for estrogen receptor and lacked evidence of a myoepithelial component, both labeled diffusely for PAX8 and WT-1, which distinguished them from their corresponding concurrent primary mammary carcinomas. These findings suggest that a subset of otherwise nondescript axillary lymph node inclusions represent endosalpingiosis and highlight the utility of PAX8 and WT-1 immunohistochemistry in distinguishing these from metastatic well-differentiated ductal carcinoma.
authors.affiliation: Departments of *Pathology †Gynecology/Obstetrics, The Johns Hopkins Medical Intuitions, Baltimore, MD ‡Department of Pathology, St Alphonsus Medical Center-Nampa, Nampa, ID.
authors.forename: Erin
authors.initials: E
authors.lastname: Carney
authors.forename: Ashley
authors.initials: A
authors.lastname: Cimino-Mathews
authors.forename: Cynthia
authors.initials: C
authors.lastname: Argani
authors.forename: Joseph
authors.initials: J
authors.lastname: Kronz
authors.forename: Russell
authors.initials: R
authors.lastname: Vang
authors.forename: Pedram
authors.initials: P
authors.lastname: Argani
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000473:pathology*; D018275:Carcinoma, Lobular / Q000556:secondary; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000096:biosynthesis; D025721:WT1 Proteins / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors; D025721:WT1 Proteins; C583751:WT1 protein, human