Endosalpingiosis Is Negative for GATA3

Arch Pathol Lab Med. 2021 Nov 1;145(11):1448-1452. doi: 10.5858/arpa.2020-0359-OA.


Context.—: Endosalpingiosis is a benign Müllerian inclusion that can mimic metastatic low-grade mammary carcinoma, particularly when encountered in axillary lymph nodes excised for breast cancer staging. Immunohistochemistry can be useful in histologically ambiguous cases, and a targeted immunopanel should include a marker of gynecologic tract origin and a marker of mammary origin. GATA3 is a sensitive immunomarker for breast carcinoma, but the immunoreactivity of GATA3 in endosalpingiosis has not been systematically evaluated.

Objective.—: To evaluate whether GATA3 immunohistochemistry could be used to differentiate endosalpingiosis from metastatic mammary carcinoma.

Design.—: Whole slide sections of 15 cases of endosalpingiosis involving nonneoplastic tissues were subjected to GATA3 immunohistochemistry. Nuclear GATA3 labeling was scored as percentage and intensity labeling, with any labeling considered positive; GATA3 labeling was recorded in all cells present in the sections.

Results.—: Half (47%, n = 7 of 15) of the endosalpingiosis cases involved lymph nodes (2 axillary, 5 pelvic) and half (53%, n = 8 of 15) involved pelvic organs or soft tissue (3 myometrial, 2 paratubal, 2 periadnexal soft tissue, and 1 pelvic sidewall). GATA3 immunohistochemistry was negative in all cases of endosalpingiosis, with intact, positive control labeling in lymphocytes. The benign fallopian tube epithelium present on the sections of paratubal endosalpingiosis displayed focal (<5%), weak labeling for GATA3, specifically within the ciliated and secretory cells.

Conclusions.—: These findings support the diagnostic utility of GATA3 immunohistochemistry and its use in a targeted immunopanel to resolve the differential diagnosis of metastatic low-grade mammary carcinoma (GATA3+) and nodal endosalpingiosis (GATA3-).

MeSH terms

  • Biomarkers, Tumor / analysis*
  • Biopsy
  • Breast Neoplasms / chemistry*
  • Breast Neoplasms / pathology
  • Carcinoma / chemistry*
  • Carcinoma / secondary
  • Diagnosis, Differential
  • Female
  • GATA3 Transcription Factor / analysis*
  • Humans
  • Immunohistochemistry*
  • Lymph Node Excision
  • Lymph Nodes / chemistry*
  • Lymph Nodes / pathology
  • Lymph Nodes / surgery
  • Lymphatic Diseases / metabolism*
  • Lymphatic Diseases / pathology
  • Lymphatic Diseases / surgery
  • Lymphatic Metastasis
  • Predictive Value of Tests


  • Biomarkers, Tumor
  • GATA3 Transcription Factor
  • GATA3 protein, human