Abstract
A 40-year-old woman with a left breast mass was referred to our hospital. Mammography showed only a mass shadow. An ultrasound showed a 30mm oval mass with distinct borders, focal cystic parts, enhanced posterior echoes, and very low internal echoes. Magnetic resonance images showed that the tumor had mixed hypo- and hyper-intense areas both on T1- and fat-suppressed T2-weighted images. In addition, time-signal intensity images showed a washout pattern in the solid part of the tumor. A vacuum-assisted biopsy of the mass showed highly atypical cells growing in a solid fashion. The patient, therefore, underwent breast-conserving surgery and sentinel node biopsy. A post-operative pathological study showed that the tumor had a solid growth pattern, intra-tumoral bleeding, a triple-negative phenotype, a nuclear grade of 3, and a Ki-67 labeling index of 90%. Very low internal echo areas were consistent with the proliferative areas of poorly differentiated cancer cells. In conclusion, tumors should be highly aggressive when they have expanding ovoid shapes, enhanced posterior echoes, and very low internal echoes.