Invasive lobular carcinoma of the breast: mammographic and sonographic evaluation.

PURPOSE To evaluate the efficacy of mammography and sonography together in the assessment of patients with pure invasive lobular carcinomas (ILCs) of the breast. MATERIALS AND METHODS We retrospectively reviewed 38 cases of pure invasive lobular carcinomas of the breast. The tumors were evaluated both mammographically and sonographically. The mammographic images were reviewed by two experienced mammographers. All patients underwent surgical management. Histopathologic assessments were made by experienced breast pathologists. RESULTS On physical examination, six tumors (15.7%) showed no clinical findings. The most common mammographic result was a spiculated mass or architectural distortion (42%). Eleven lesions (29%) were mammographically negative. Five cases (13%) showed pleomorphic or heterogeneous calcifications that were compatible with Breast Imaging Reporting and Data System (BI-RADS) 4 or 5. The most common sonographic result was a hypoechoic mass with or without shadowing (60.5%). Four tumors (10.5%) were sonographically invisible. Two cases (5%) were negative, and 25 cases (65.8%) were positive in both modalities. The overall sensitivity was 71.05% for mammography and 89.47% for sonography. The number of tumors detected by either of these two modalities was 36, and the overall sensitivity was 94.73%. CONCLUSION Mammography and ultrasonography are useful imaging methods in the evaluation of invasive lobular carcinoma. Because of the low rate of suspicious calcifications and low density of lesions, the false-negative rate tends to be high for these tumors. With the use of sonography and mammography together, invasive lobular carcinomas can be detected with a sensitivity of 94.73%. We recommend additional sonographic evaluations for all patients, especially those with dense breast tissue with or without positive mammographic findings.