Cystic adenomyoepithelioma of the breast.

Cystic adenomyoepithelioma of the breast is a rare tumor. We report a case of this entity in a 42-year-old woman who presented with a lump behind her left nipple. Clinical examination suggested the diagnosis of a cyst. Ultrasound showed a cyst with an intracystic mass. The lesion was biopsied and found to be a cystic adenomyoepithelioma.