Radiological features of invasive lobular breast carcinoma: multicenter study in 390 patients

From the radiological point of view, the invasive lobular carcinoma of the breast is among the group of lesions that remain undiscovered by mammographic screening. This is due to its low incidence, nondescript radiological presentation, the lack of evidence of malignancy and the presence of microcalcifications, among other factors. We carried out a descriptive multicenter study of the mammographic and ultrasonographic features in 390 cases of invasive lobular carcinoma of the breast treated between 1980 and 1997 at Hospital San Carlos, Hospital Doce de Octubre and Fundacion Jimenez Diaz in Madrid, Spain. The findings were recorded and compared with those reported in the literature. In addition, each lesion was classified according to grade of malignancy to determine the diagnostic reliability of the two methods. Mammography was performed in 98.9% of the study population and ultrasound in 53.3%. The presence of spiculated masses was the finding associated with the greatest positive predictive value of malignancy in both diagnostic methods. Microcalcifications were not frequently observed in mammographic images (20.9%). The percentage of false positives was lower for mammography than for ultrasound. Despite the general belief that invasive lobular breast carcinoma is difficult to diagnose, the majority of the patients in our study population presented some sign of malignancy that led to the definitive pathological study. (Author) 25 refs