A Mucocele-like tumor (MLT) of the breast is a rare lesion and is pathologically characterized by mucin-filled cysts and extravasated mucin present in the adjacent stroma. Since the first report of an MLT of the breast by Rosen in 1986, an MLT has been considered as part of a diverse spectrum of pathological lesions including benign tumors, atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and mucinous carcinomas. We described a case of an MLT of the breast associated with DCIS and a mucinous carcinoma in a 46-year-old female patient who was treated with a left modified radical mastectomy and a sentinel lymph node biopsy. This case supports the concept of a spectrum of pathological lesions for an MLT, including benign lesions, columnar hyperplasia, ADH, DCIS and mucinous carcinomas.