Ultrasonographic evaluation of invasive lobular carcinoma

Purpose. To compare ultrasonographic (US) and mammographic findings and tum or size measurements of invasive lobular carcinoma (ILC). Material and Methods. US diagnoses and mammographic findings were compared in 95 patients with pure ILC, including 46 palpable and 49 nonpalpable tumo rs. The diameters of tumors measured by mammography, US, and pathology were compared in 70 of the 95 patients using scatter plots and correlation anal ysis. Results. Eighty-two (86.3%) of the ILCs were correctly diagnosed as maligna nt tumor, 5 (5.3%) were diagnosed as focal abnormality and only 2 patients had normal findings on US.; The most common mammographic findings were a sp iculated mass (57%) and a focal asymmetric density (15%). US correctly diag nosed 8 of 12 patients with normal or equivocal mammographic findings. The correlation of tumor size assessment on imaging and pathology revealed that US measurements including the "halo" (r=0.69) was superior to that of mamm ography (r=0.59). ILCs larger than 30 mm were heavily underestimated by bot h methods. Conclusion. Malignant tumor was diagnosed on US in most of the patients wit h ILC. US tumor measurement including the "halo" predicted tumor size most accurately. The correlation between imaging measurements and tumor diameter on histology was lower for ILCs than reported for populations of mixed car cinomas.