case_images: PMC8555694_01
case_images: Timeline of the relevant data of this case.
case_images: fonc-11-577227-g001.jpg
case_images: PMC8555694_01_fonc-11-577227-g001.jpg
case_images: f1
case_images: Nipple discharge was not reported ( Figure 1 ).
case_images: (A) Ultrasonographic image showing multiple hypoechoic lesions in the right breast. The large masses comprising nearly the entire right breast, with lobulated irregular margin, the banded median-high echogenic septum was seen inside the mass. (B) Color flow Doppler image showing abundant blood flow signals. (C, D) Different spliced images of the tumor showed irregular margin with multiple septa.
case_images: fonc-11-577227-g002.jpg
case_images: PMC8555694_01_fonc-11-577227-g002.jpg
case_images: f2
case_images: Multiple banded hyperechogenic septa were noted ( Figure 2 ).
case_images: Full-field digital mammography. (A) Craniocaudal position and (B) mediolateral oblique position showed multiple high-density irregular masses, some of which were integrated with obscured septa, with multiple lobulations. Note the red arrow in panel A; the margin of the lesion was obscured by surrounding structures. Breast Imaging-Reporting and Data System (BI-RADS) 3.
case_images: fonc-11-577227-g003.jpg
case_images: PMC8555694_01_fonc-11-577227-g003.jpg
case_images: f3
case_images: There is no suspicious finding in the left breast ( Figure 3 ).
case_images: (A-D) Craniocaudal position of digital breast tomosynthesis. The red arrow shown in panels (A, B) demonstrated that the margin of the mass was obscured; however, the red arrow area in panels (C, D) showed unshielded margin of the mass, which was more obvious compared with that in 
  Figure 3A
  .
case_images: fonc-11-577227-g004.jpg
case_images: PMC8555694_01_fonc-11-577227-g004.jpg
case_images: f4
case_images: No enlarged lymph nodes were noted ( Figures 4 ,  5 ).
case_images: (A-D) The mediolateral oblique position of digital breast tomosynthesis demonstrated improvement in sharpness and internal septa of the large mass; it measured 7.8 cm x 9.1 cm x 7.4 cm in size, with irregular margins and multiple lobulations. Breast Imaging-Reporting and Data System (BI-RADS) 4A.
case_images: fonc-11-577227-g005.jpg
case_images: PMC8555694_01_fonc-11-577227-g005.jpg
case_images: f5
case_images: No enlarged lymph nodes were noted ( Figures 4 ,  5 ).
case_images: (A) Low power, the tumor lacked obvious leaflike processes while it partially retained the lobular architecture. The tumor infiltrated peripheral tissues, including fat (right middle margin). The red box indicated the corresponding area shown in panel (B) Internal bar = 6 mm. (B) Higher power showed high stromal cellularity with obvious dysplasia, active mitoses, and pathologic mitosis [middle in the insert (embraced with red box, located left upper corner)]. The ducts in the tumor kept a nearly normal contour, and the stromal cellularity adjacent to the epithelium did not obviously increase. Internal bar = 500 mum.
case_images: fonc-11-577227-g006.jpg
case_images: PMC8555694_01_fonc-11-577227-g006.jpg
case_images: f6
case_images: As for the determination of malignancy, this case demonstrated invasive growth, significant pleomorphism, active mitosis (>10/10 HPF or >5/mm2) with pathological mitosis, and was rich in mesenchymal cells, so it was classified as malignant ( Figure 6 ).