ABSTRACT
PURPOSE: To review the US findings in invasive lobular breast carcinoma which is often difficult to diagnose clinically and mammographically. MATERIAL AND METHODS: The mammographic and US findings in 63 cases of pure invasive lobular carcinoma diagnosed at our institution in 1990-1996 were reviewed retrospectively. The US findings were classified as positive, negative or indeterminate for malignancy. RESULTS: Forty-nine of the 63 lobular carcinomas (78%, 95% CI 65.5-87.3%) were US-positive, and 51 (81%, CI 95% 69.1-89.8%) were mammography-positive. The US visibility of the carcinomas was affected by their palpability and mammographic appearance, and the radiographic density of the breasts. Indeterminate US findings (architectural distortion with acoustic shadowing) were visualized in 4 of the 10 cases that had asymmetric densities at mammography. CONCLUSION: The sensitivity of US for lobular carcinoma was not statistically different from that of mammography. The methods were complementary, especially with regard to evaluating dense breasts and lesions which were difficult to assess clinically and mammographically.
