Ductal carcinoma in situ with isolated tumor cells in the sentinel lymph node in a 17-year-old adolescent girl.

We report here a quite rare case of ductal carcinoma in situ (DCIS) with isolated tumor cells in the sentinel lymph node in a 17-year-old adolescent girl whose mother also had advanced breast cancer. Findings included an elastic mass in the right breast accompanied by serous nipple discharge. DCIS of the breast was diagnosed following core needle biopsy. Although no invasive focus was clearly observed in the mastectomy sample, isolated tumor cells were found in the sentinel lymph node. Although the family refused genetic testing, a hereditary abnormality may have played a role in the carcinogenesis in this case.