Bilateral Breast Cancer Radiologic Pathologic Correlation
Developing architectural distortion in 68F • Xray of the Week 2017 • Week #42
This 68-year old woman was treated for an 8 mm tubular cancer in her left breast at age 48. She is asymptomatic but was called back from screening for assessment of an architectural distortion in the upper portion of her right breast and an enlarged lymph node in the right axilla. Clinical breast examination revealed a large palpable thickening in the central portion of the right breast and a palpable right axillary lymph node. No tumor was palpable in the left breast.
Figure 1. Bilateral mammogram
Figure 2. Bilateral mammogram 26 months later.
Figure 3: Progression of architectural distortion in the right breast over time. Note the development of extensive architectural distortion which eventually fills the entire central portion of the breast. The breast has correspondingly decreased in size. There is a pathological right axillary lymph node.
Figure 4: Automated breast ultrasound (ABUS) of the right breast, lateral compression, showing a series of images of 2 mm thick, consecutive coronal tissue slices. The images demonstrate the obvious, extensive architectural distortion and a large tissue defect, caused by the cancer.
Figure 5 a-g. Breast MRI, axial (a-c), sagittal (d-g) images. Description of the MRI finding: There is a 6.0 x 5.7 x 7.3 cm region of diffuse, heterogeneous contrast enhancement in the right breast, characteristic for diffusely infiltrating breast cancer. Note the enlarged draining veins in the right breast, causing an asymmetry in vessel size between the right and left breasts. Also, pathological lymph nodes were seen in the right axilla. Left breast: scar following previous surgery, causing the nipple to deviate laterally. Five cm deep to the nipple there is a 9 x 1.3 x 1.1 cm lesion with radiating structure and contrast enhancement, suggesting a local recurrence (encircled). MRI exam courtesy: Mats Ingvarsson, M.D.
Due to the suspicious appearance on mammography, ultrasound, and MRI, ultrasound guided biopsy was performed followed by right axillary lymph node biopsy.
Figure 6: Ultrasound and mammogram image of a pathologic lymph node in the right axilla and the histologic confirmation of the 14-g core biopsy specimen. Histopathology images show this diffusely infiltrating breast cancer at the cellular level. Histology images are courtesy of Tibor Tot, MD PhD - Associate Professor, Department of Pathology and Clinical Cytology, Central Hospital Falun, Falun, Sweden
Because of the extent of disease, mastectomy was required. Histology from the right mastectomy was a 7.5 x 5.0 cm diffusely infiltrating breast cancer. pN 1/7. Biomarkers: ER/PR +ve, HER2 –ve, Ki67 1%.
Figure 7: Correlation of the mastectomy specimen slice with large format thick section (3D) histopathology. The extensive proliferation of the fibrous tissue (mesenchyme) dominates the image, accounting for the findings at ABUS and mammography. This diffusely infiltrating invasive carcinoma occupied the entire central and retroareolar region of the breast. Histology images are courtesy of Tibor Tot, MD PhD - Associate Professor, Department of Pathology and Clinical Cytology, Central Hospital Falun, Falun, Sweden.
A spiculated lesion in the left breast was also noted on followup mammography. This was subsequently biopsied and was shown to be invasive breast cancer.
Figure 8: Mammography of the left breast demonstrating a spiculated mass. Ultrasound shows the irregular hypoechoic mass with marked shadowing. This was subsequently biopsied and was shown to be well differentiated invasive breast cancer. Histology images are courtesy of Tibor Tot, MD PhD - Associate Professor, Department of Pathology and Clinical Cytology, Central Hospital Falun, Falun, Sweden
The patient elected for left mastectomy. Histology of the left mastectomy was 1.5 x 1.2 cm unifocal, well differentiated invasive breast cancer. pNX. Biomarkers: ER/PR+ve, HER2-ve, Ki67 1%.
Figure 9: Mammographic-histologic correlation of the solitary breast cancer detected in the left breast. Histology images are courtesy of Tibor Tot, MD PhD - Associate Professor, Department of Pathology and Clinical Cytology, Central Hospital Falun, Falun, Sweden
Discussion
The diffusely infiltrating breast cancers are notoriously missed on the mammograms. They are usually 5-9 cm in size at the time of detection and have a poor long-term outcome. The ability to evaluate the global anatomy of the breast using automated breast ultrasound can readily detect the presence of extensive architectural distortion.
We propose that the diffusely infiltrating breast cancers may originate from mesenchymal stem cells (progenitors) through a complex process of mesenchymal-epithelial transformation (MET). The imaging findings of diffusely infiltrating breast cancer are strikingly different from the imaging findings of breast malignancies originating either from the TDLUs (AAB) or the lactiferous ducts (DAB), suggesting that it may have a different site of origin. The spider’s web-like mammographic presentation of diffusely infiltrating breast cancer may be difficult to detect, even in predominantly adipose breasts, regardless of a large tumor size, while stellate and circular tumors (AAB) can be mammographically detectable in an adipose breast at the size of a few mm.
The predominance of mesenchyme in the diffusely infiltrating breast malignancy allows it to be imaged with greater sensitivity by ultrasound than by mammography. The thin sheets or veils of tissue reflect the ultrasound waves, but are relatively easily penetrated by X-rays. There is a lack of extensive neoangiogenesis within the massive fibrous tissue, accounting for an initial slow or moderate contrast enhancement on breast MRI, followed by a persistent enhancement pattern, as opposed to the more intense initial enhancement and washout pattern characteristic of DAB & AAB (Ref.: Tabár, L, T Tot, PB Dean, O Puchkova: Diffusely Infiltrating Breast Cancer, Part I. Vol XI of the 3D book series).
Regarding the left breast lesion, stellate or circular invasive tumors originate from the acinar cells of the terminal ductal lobular unit(s), producing acinar adenocarcinoma of the breast (AAB). These tumors are often situated at the periphery of the dense fibroglandular tissue, causing subtle parenchymal contour changes (the contour may be either retracted or protruding), leading to perception problems.
References:
Kim MJ, Kim EK,Kwak JY et al, Bilateral Synchronous Breast Cancer in an Asian Population: Mammographic and Sonographic Characteristics, Detection Methods, and Staging. AJR. American Journal of Roentgenology. 2008;190: 208-213. 10.2214/AJR.07.2714
Other breast imaging cases on Global Radiology CME:
László Tabár, MD, FACR (Hon) the Professor Emeritus of Radiology Uppsala University, Faculty of Medicine, Sweden and the Medical Director Emeritus of the Department of Mammography, Falun Central Hospital, Sweden. Through his company, Mammography Education, Inc, he has also been the course director and principal lecturer at more than 300 mammography courses on 6 continents. His pioneering research has laid the foundation for early detection through modern mammographic screening. Dr. Tabár is the recipient of numerous awards including the Gold Medal from the Society of Breast Imaging, American Cancer Society's Distinguished Service Award, and the first Alexander Margulis Award for Scientific Excellence from the Radiological Society of North America (RSNA).
