Abstract:

Objective To explore the clinicopathological features, immune phenotypes, and differential diagnosis of breast adenoid cystic carcinoma. Methods The clinical data of 6 patients with breast adenoid cystic carcinoma were collected and the clinical and histopathological features and their prognosis were retrospectively analyzed. Results The ages of the 6 patients were between 49 and 86 years old. On gross inspection, these tumors located in left breast with clear boundary, pale or grey yellow colour, and lobulated or cystic shape. Microscopically, these tumors showed infiltrative growth with cribriform, trabecula-tubular and solid patterns. The neoplastic parenchyma was consisted of glandular epithelium, basaloid cells, and sebaceous differentiated cells. Immunohistochemically, ER, PR, and CerbB-2 of tumour cells were all negative. The epithelial cells expressed CK7, CK5/6, and CD117. Basaloid cells has the features of myoepithelial cells and expressed CK5/6 and P63. Four patients underwent modified radical mastectomy without ipsilateral axillary lymph node metastasis and 2 patients underwent extended recection. There was no relapse or metastasis after being followed up for 3-66 months. Conclusion Breast adenoid cystic carcinoma is a low-grade malignant tumor with unique histopathological characteristics and immune phenotype. The prognosis is satisfactory and the incidence of lymph node metastasis is rare.

Key words: breast carcinoma, adenoid cystic carcinoma, pathology, clinical, immunohistochemistry