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Updated: Aug 8, 2026
Changes in Mammary Gland Morphology and Breast Cancer Risk in Rats
Published on: October 16, 2010
Apparent ipsilateral decrease in breast size at mammography: a sign of infiltrating lobular carcinoma
J A Harvey1, R E Fechner, M M Moore
1Department of Radiology, University of Virginia, Charlottesville 22908, USA.
Purpose:
To assess if infiltrating lobular carcinoma (ILC) is associated with an ipsilateral mammographic decrease in breast size.
Materials And Methods:
Mammographic change in size was evaluated by measuring the distance from the nipple to the pectoralis major muscle on the mediolateral oblique view of the diagnostic mammogram and on a preceding mammogram in 30 patients with ILC. Clinical, mammographic, and histopathologic findings were retrospectively reviewed.
Results:
Five patients (17%) had an ipsilateral decrease in mammographic size. No patients noticed a physical decrease in breast size. Patients with an ipsilateral decrease in mammographic size most commonly had breast thickening at examination (four of five patients [80%], P < .001) and either a focal asymmetry density (three of five patients [60%]) or architectural distortion (one of five patients [20%]) at mammography; those patients with no change in size most commonly had a palpable mass (six of 25 patients [24%]) or normal findings (19 of 25 patients [76%]) and a mass (13 of 25 patients [52%]) at mammography. The mean tumor size was 66 mm for those with an ipsilateral size decrease and 16 mm for those with no size decrease (P < .001). At histologic analysis, tumors associated with an ipsilateral decrease in mammographic size had more diffuse involvement of the breast, and discrete masses were not seen.
Conclusion:
An apparent decrease in mammographic size may help identify cases of ILC, especially when associated with thickening at clinical examination and focal asymmetric density at mammography.
