Endometrioid Tubal Intraepithelial Neoplasia (E-TIN) of the Fallopian Tube: A Case Series

Int J Gynecol Pathol. 2020 Nov;39(6):552-557. doi: 10.1097/PGP.0000000000000650.


Although serous tubal intraepithelial carcinoma has been well described in the distal fallopian tube as precancers of pelvic high-grade serous carcinoma, endometrioid precancers have drawn less attention. Recently, endometrioid precursor lesions have been identified and reported to have a specific immunophenotype (PAX2-, ALDH1+, diffuse nuclear beta-catenin), as well as an association with both uterine and ovarian endometrioid carcinomas. These have been referred to as endometrioid (or type II) secretory cell outgrowths. A subset of endometrioid secretory cell outgrowths show architectural complexity resembling hyperplasia of the endometrium and have been referred to as endometrioid tubal intraepithelial neoplasia. We report 4 cases of endometrioid tubal intraepithelial neoplasia with clinical correlation and morphologic differential diagnosis.

MeSH terms

  • Aged
  • Carcinoma in Situ / chemistry
  • Carcinoma in Situ / pathology*
  • Carcinoma, Endometrioid / chemistry
  • Carcinoma, Endometrioid / pathology*
  • Diagnosis, Differential
  • Endometrial Neoplasms / chemistry
  • Endometrial Neoplasms / pathology
  • Fallopian Tube Neoplasms / pathology*
  • Fallopian Tubes / pathology
  • Female
  • Humans
  • Middle Aged
  • PAX2 Transcription Factor / analysis
  • Precancerous Conditions / pathology*
  • Tumor Suppressor Protein p53 / analysis
  • beta Catenin / analysis


  • PAX2 Transcription Factor
  • PAX2 protein, human
  • Tumor Suppressor Protein p53
  • beta Catenin