Journal Article

High-grade HER2-positive mucoepidermoid carcinoma of the breast: a case report and review of the literature

Mura, Mario Della, Vander Borght, Sara, Foschini, Maria P., Van Eyken, Peter, Smeets, Ann, Hauben, Esther, Keupers, Machteld, Clement, Céline, Waumans, Lise, Nevelsteen, Ines, Floris, Giuseppe, Weltens, Caroline

2023

Overview

Background Mucoepidermoid carcinoma of the breast is a rare special type of salivary gland-like tumor of the breast, usually displaying triple-negative phenotype. To date, only 64 cases have been reported in the English literature. Herein, we report the first case of mucoepidermoid carcinoma of the breast with human epidermal growth factor receptor 2 gene amplification. Case presentation A 58-year-old Caucasian woman treated with breast-conserving surgery, radiotherapy, and chemotherapy for an invasive breast carcinoma of no special type, relapsed 20 years later in the ipsilateral left breast. Histological examination of the core needle biopsy of the relapse deferred to the surgical specimen for the definitive diagnosis, because of the broad differential diagnosis. On the resected specimen we observed the presence of a poorly differentiated carcinoma with mucoepidermoid carcinoma of the breast typical features consisting of epidermoid, intermediate and mucinous cells lacking true keratinization, in keeping with the latest World Health Organization diagnostic criteria. The mucoepidermoid carcinoma of the breast was weakly estrogen receptor and androgen receptor positive and progesterone receptor negative, but exceptionally showed human epidermal growth factor receptor 2 gene amplification. Mastermind-like transcriptional coactivator 2 gene translocations were not detected by fluorescent in situ hybridization. The patient received adjuvant chemotherapy with anti-human epidermal growth factor receptor 2 therapy but no endocrine therapy. After 61 months of follow-up, no signs of local or distant recurrence were observed. Conclusions Mucoepidermoid carcinoma of the breast is a very rare entity. Despite being most frequently triple negative, the standard evaluation of receptor status is mandatory, as well as strict application of World Health Organization diagnostic criteria for correct patient management.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Breast cancer / Cancer / Cancer therapies / Carcinoma / Case Report / Chemotherapy / Cloning / Cytokeratin / Endocrine therapy / Epidermal growth factor / Estrogen / Estrogens / Exocrine glands / Family Medicine / Fluorescence in situ hybridization / Gene amplification / General Practice / Genetic transcription / HER2 / Internal Medicine / Lumpectomy / Mammography / Medical colleges / Medicine / Medicine & Public Health / Metastasis / Morphology / Mortality / Mucoepidermoid carcinoma of the breast / Primary Care Medicine / Progesterone / Proteins / Public Health / Radiation therapy / Salivary gland-like tumors of the breast / Surgical Oncology / Triple-negative breast cancer / Tumors / World health