Hamartoma of the breast.

Mammary hamartomas are unusual lesions with distinctive radiologic and pathologic features. They are well circumscribed, mobile tumors showing no adherence to skin or muscle. Mammographic studies show a peripheral, luscent halo, and the mass is radiographically similar in pattern to a normal breast ("breast within a breast"). Calcification is not present. Histologically, these encapsulated lesions are composed of various breast tissue components such as ducts, lobules, stroma prominently adipose, and smooth muscle, without any particular arrangement. Local surgical resection is the treatment of choice. Hamartomas of the breast are benign lesions that need to be distinguished from other breast neoplasms such as fibroadenomas, lipomas, and cystosarcoma phyllodes.