Invasive mucinous carcinoma of the breast.

Mucinous carcinoma of the breast is one of the rarer forms of intramammary cancer, often presenting as a lobulated, fairly well circumscribed mass on mammography, sonography, and gadolinium-enhanced magnetic resonance imaging. It accounts for 1% to 7% of all breast cancers and generally carries a better prognosis than other types of malignant breast cancers. Metastatic disease occurs at a lower frequency than in other types of invasive carcinoma. We present an atypical case of mucinous carcinoma in a woman who presented with a palpable intramammary lymph node metastasis from an unknown breast primary. Subsequent magnetic resonance imaging and percutaneous biopsy demonstrated histologic findings consistent with a mixed mucinous neoplasm with a micropapillary pattern.

The radial scar of the breast diagnosed at core needle biopsy.

The radial scar (RS) or complex sclerosing lesion (CSL) of the breast represents a management dilemma on diagnosis at breast core needle biopsy because of the risk of associated malignancy identified only upon surgical excision. To determine our experience, we retrospectively reviewed core needle biopsies performed at the Darlene G. Cass Breast Imaging Center from 2006 to 2011, identifying 67 patients with RS or CSL, and correlated histology at excisional biopsy with core biopsy results. Of the 67 cases, 6 (9%) were associated with malignancy at surgical excision. The average size of the RS or CSL was 1.42 cm. In conclusion, RS or CSL diagnosed at core needle biopsy still warrants surgical excision because of the significant percentage (9%) of cases with associated malignancy.