Ultrasonographic findings of invasive lobular carcinoma differentiation of invasive lobular carcinoma from invasive ductal carcinoma by ultrasonography.

BACKGROUND: Although controversy exists, invasive lobular carcinoma (ILC) differs in its high frequency of microscopically positive margins after conservative therapy compared to invasive ductal carcinoma (IDC). If ILC could be recognized by imaging modalities, it would provide important information for surgeons. We tried to confirm whether it is possible to distinguish ILC from other invasive carcinomas by ultrasonography (US).

METHODS: A total of 81 histologically confirmed cases of IDC, including 26 cases of papillotubular carcinoma, 28 cases of solid-tubular carcinoma and 27 cases of scirrhous carcinoma, as well as 24 cases of ILC were selected and retrospectively studied with regard to the features of mass lesions on US examination.

RESULTS: The sensitivities of US for papillotubular carcinoma, solid-tubular carcinoma, scirrhous carcinoma and ILC were 88.5%, 100%, 92.6% and 91.7% respectively. We could divide invasive breast cancer into two groups by US findings. One group had a low frequency of malignant findings and consisted of papillotubular and solid-tubular carcinomas, and the other group had a high frequency of malignant findings and consisted of scirrhous carcinomas and ILC. However, there were no statistical differences between papillotubular carcinoma and solid-tubular carcinoma or between scirrhous carcinoma and ILC with regard to the US findings.

CONCLUSIONS: Scirrhous carcinoma, the most common type of IDC, and ILC are difficult to distinguish by US. Therefore it is difficult to separate ILC from IDC by US.