抄録
We report a case of adenoid cystic carcinoma of the breast. A 48-year-old female presented with a solid mass with a cystic region measuring 1.7×1.5 cm in the left breast. The radiological differential diagnosis included phylloides tumor, fibroadenoma, and carcinoma. Intraoperative histological frozen section examination did not reveal any typical features of adenoid cystic carcinoma. Imprint smears from the breast tumor showed many spherical clusters predominantly composed of small round cells with finely granular chromatin, suggestive of myoepithelial cells, and also cells with relatively large nuclei, suggestive of epithelial cells.