ObjectiveTo explore the ultrasonographic and pathological manifestations of primary bilateral breast cancer (PBBC). MethodsThe ultrasonographic and clinical manifestations of 24 patients with PBBC confirmed by surgical pathology and clinical examination between January 2001 and April 2009 were studied retrospectively. The study contained 9 bilateral synchronous breast cancer patients aged from 41 to 60 years old, averaging 47.3 years, and 15 bilateral asynchronous breast cancer patients. For patients with bilateral asynchronous breast cancer, the age on the first lesion diagnosis was between 33 to 61 years with an average of 43.2; the age on the second lesion diagnosis was from 38 to 69 years old averaging 49.1; and the interval time between the first and second lesion diagnosis was from 3 to 8 years, averaging 5.9 years. ResultsThe site of PBBC was more located in upper outer quadrant. Most lesions had obscure boundary, irregular shape, and heterogeneous internal echo in ultrasonographic manifestation. The vertical and horizontal diameter ratio > 1, acoustic shadowing, and microcalcification occurred in some of the lesions. The bloodstream of the lesions were mainly Adler gradeⅡorⅢ. ConclusionsMost PBBC has typical ultrasonographic manifestations. The follow-up of PBBC patients should be based on imaging such as ultrasonography. The biopsy guided by ultrasonography can elevate the detection rate of PBBC.