PMC9149475_01
a Mammogram MLO view showing a dense mass lesion with smaller hypodense areas. b Ultrasound scan view showing a circumscribed lesion with an inhomogeneous isoechoic to hyperechoic signal with a small hypoechoic halo and minimal peripheral vascularity.
cro-0015-0455-g01.jpg
PMC9149475_01_cro-0015-0455-g01.jpg
F1
The diagnosis was indeterminate, but there was a suspicion of malignancy, and therefore the lesion was radiologically classified under the BIRADS4 category (Fig. 1a, b).
a H&E stain (x2 power magnification): low power view of the core biopsy shows spindle cell proliferation among fat-rich stroma. b H&E stained section (x20 magnification) shows the lesion at higher magnification. c H&E stained section of the excisional biopsy (x4 power magnification) showing spindle cells arranged haphazardly with a vascular rich background. Many fat cells are seen in between. d STAT6 immunostain shows diffuse nuclear positivity in the lesional cells.
cro-0015-0455-g02.jpg
PMC9149475_01_cro-0015-0455-g02.jpg
F2
No ductal epithelial component was observed, unlike in hamartoma or fibroepithelial lesions (Fig. 2). Tumor cells were strongly and diffusely immunopositive with vimentin, CD34, STAT-6, and negative with SMA, desmin, and S100-P, an IHC profile that favors the diagnosis of a solitary fibrous tumor, lipomatous variant (Fig. 2a-d).