[Diagnostic difficulties in infiltrating lobular breast cancer: value of ultrasonography. 33 cases].

Thirty three invasive lobular carcinoma (ILC) were submitted to mammography, ultrasonography and finally surgery. The type of tumor proliferation and the absence of microcalcifications within the invasive tissue led to 15% of false negative responses in the mammographic analysis. Ultrasonography disclosed only 12% of false negatives. Sonographic appearance, especially fine needle aspirations or microbiopsy under ultrasonographic control, allows modification of mammographic and clinical diagnosis errors. Thus, this method appears of importance in diagnosis of ILC.