Aim: To assess the ability of ultrasound to detect small (<10 mm) invasive lobular carcinoma (ILC) of the breast. Previous reporters have suggested very low sensitivity rates for identifying these tumours on ultrasound. We reviewed our own experience to see how our figures compared.
Materials and methods: We retrospectively analysed all cases of pure small ILC diagnosed at Breast Test Wales over the first 9-year period of the National Health Breast Screening Programme. All mammograms and ultrasound examinations were reviewed and findings assessed. We also obtained similar information on small invasive ductal carcinoma (IDC) for comparison.
Results: Sixteen cases of pure small ILC were diagnosed during the study period. Fourteen of the 15 patients (93%) who underwent an ultrasound examination had abnormal findings. A definitive pre-operative diagnosis using ultrasound guided sampling was obtained in all 14 patients. A larger number of small IDCs (152) were diagnosed during the same study period and the sensitivity of ultrasound in this group was recorded as 80%.
Conclusion: Our findings suggest a much higher sensitivity for ultrasound in the detection of small ILC than has been previously described. Its use should be encouraged particularly as it facilitates biopsy and pre-operative diagnosis.