乳房錯構瘤是一種罕見之乳房良性腫瘤，切除手術及病理化驗來做鑑別診斷。我們報告一位49歲女性，以可觸摸到無痛性右側乳房腫塊為臨床表徵。超音波看到一個邊緣清楚，低迴音的腫塊。病患接受手術切除病灶，病理診斷證實為乳房錯構瘤。

Breast hamartoma is an uncommon benign tumor rarely associated with malignancy. An excision and histological examination is necessary for the differential diagnosis. We report a case of a 49-year-old female patient presenting with a lump in the right breast. Ultrasound examination which demonstrated a 4.4*1.1 cm hypoechoic lesion with lipoma. Partial mas-tectomy was arranged and the diagnosis of a hamartoma was confirmed by the histological examination.