Low-Grade Adenosquamous Carcinoma of the Breast Masquerading as a Fibroepithelial Lesion on Core Biopsy: A Challenging Case

Pathobiology. 2024;91(6):455-462. doi: 10.1159/000540029. Epub 2024 Jul 17.

Abstract

Introduction: Diagnosing low-grade adenosquamous carcinoma (LGASC) presents significant challenges due to its subtle morphology, variable immunohistochemical expression, and resemblance to benign lesions like radial scar and complex sclerosing lesions.

Case presentation: We present a case of a 53-year-old woman with a subareolar mass initially thought to be a fibroepithelial neoplasm on core biopsy. Subsequent wide excision revealed LGASC with oestrogen receptor expression (weak to moderate intensity, 40% of tumour cells).

Conclusion: These findings, rarely reported, highlight the difficulty of diagnosing LGASC on small tissue samples.

Keywords: Breast cancer; Core biopsy; ER positivity; Frozen section; Low-grade adenosquamous carcinoma.

Publication types

  • Case Reports

MeSH terms

  • Biopsy, Large-Core Needle
  • Breast / pathology
  • Breast Neoplasms* / diagnosis
  • Breast Neoplasms* / pathology
  • Carcinoma, Adenosquamous* / diagnosis
  • Carcinoma, Adenosquamous* / pathology
  • Diagnosis, Differential
  • Female
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Neoplasms, Fibroepithelial / diagnosis
  • Neoplasms, Fibroepithelial / pathology
  • Receptors, Estrogen / metabolism

Substances

  • Receptors, Estrogen