Abstract
A 66-year-old woman with a 3-year history of left breast pain visited our hospital after noticing a gradual increase in pain. A 15-mm mass with good mobility was palpable in the AC area of the left breast, and no axillary lymph node swelling was observed. Mammography (MMG) showed a Category-4 mass shadow with indistinct boundaries in the left AC area. Ultrasonography showed an indistinct, hypo-to-iso echoic, 14-mm mass in the left AC area, with HALO sign and interruption of the anterior boundary mammary gland. As a result, a Category 5 lesion was diagnosed, and either papillary ductal carcinoma or scirrhous carcinoma was suspected. A strong, non-uniform contrast effect was observed peripherally on contrast-enhanced ultrasonography. Core needle biopsy (CNB) diagnosed adenoid cystic carcinoma, and left breast-conserving surgery and sentinel lymph node biopsy were performed. Pathological findings showed the formation of large and small nests with a trabecular arrangement, and invasive adenoid cystic carcinoma was diagnosed. Vascular components were abundant at the tumor edges, and the strong contrast effect at the edges from contrast-enhanced ultrasonography was consistent with these histopathological findings.
