History
56-year-old asymptomatic woman presents for screening mammogram.
Diagnosis
Invasive lobular carcinoma
Description of Findings Mammogram: a dense, spiculated mass is best identified on the left CC view.
Left Breast Ultrasound: ill-defined, irregular, hypoechoic masses with posterior acoustic shadowing. Additional images demonstrate thickening of soft tissue planes, and areas of posterior acoustic shadowing without a well defined mass.
MRI: an irregular, enhancing, mass associated with enhancing septa/strands is more extensive than was evident mammographically. It demonstrates a continuous enhancement pattern.
Discussion
ILC makes up 10-15 % of breast cancers. About 65% have nodal disease at diagnosis. Clinically, patients are often asymptomatic, but may present with a focal area of breast induration or tenderness.
Mammographically, these tumors most commonly present as a spiculated mass, but the mammogram may also be deceptively benign. It may present as an area of parenchymal asymmetry or architectural distortion, which may be seen on one view only, most commonly the CC view. Diffusely increased breast density or decreased breast size may be seen. Calcifications are not typical.
Sonographically, a heterogeneous, hypoechoic, angular, ill-defined mass may be seen, or posterior acoustic shadowing with or without a visible mass. Less commonly, the mass may be lobulated, well-circumscribed and hypoechoic, occasionally even hyperechoic. Thickening of soft tissue planes may result in a “wider than tall” appearance.
MRI often shows a malignant, rapid enhancement and washout/plateau pattern, however a continuous enhancement pattern may also be seen, as in this case. The lesion may present as a solitary mass or multiple masses, with or without intervening enhancing tissue, or with diffuse parenchymal enhancement. MRI may demonstrate the presence of previously unrecognized additional malignant lesions, both ipsilaterally and contralaterally, thus altering management in several cases.
References
Cardenosa, G. Breast Imaging Companion. Lippincott Williams and Wilkins, 2008.
Rosen, PP. Rosen’s Breast Pathology. Lippincott Williams and Wilkins, 2001; 627-628
Whitman GJ, Huynh PT, Patel P, Wilson J et al. Sonography of Invasive Lobular Carcinoma. Ultrasound Clin 2007; 1: 645-660
Shaw de Paredes, E. Atlas of Mammography. Wolters Kluwer Health, 2007; 245-247
Quan ML, Sclafani L, Heerdt AS, Fey JV, Morris EA, Borgen PI (2003) Magnetic resonance imaging detects unsuspected disease in patients with invasive lobular cancer. Ann Surg Oncol 10:1048–1053
Case Contributed By
Susanna C. Spence, MD
Phan Huynh, MD - Attending St. Luke’s Episcopal Hospital
