PMC9664933_01
(A) Red discoloration and swelling of the right forearm up to the mid-arm. Redness and swelling are circumferential throughout the forearm and mid-arm. (B) Ultrasound color Doppler of the right forearm in longitudinal view shows marked hypervascularity in the swollen subcutaneous layer and muscles. Both arterial and venous spectral waveforms are detected. There is no margin seen bordering the lesion. These findings are suggestive of a high-flow vascular tumor.
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F1
A clinical examination revealed a huge discrete swelling of the right upper limb extending from her right wrist up to the mid-arm and was associated with red-bluish discoloration, which was dry, cool, and non-tender (Figure 1A). The MRI of the right forearm demonstrated a diffuse infiltrative lesion that crossed multiple planes in the forearm without a clear margin (Figures 2A,B), and the ultrasound doppler confirmed the lesion to be a high-flow vascular tumor (Figure 1B).
MRI of the right forearm: (A,B) at diagnosis; (A) coronal T1 fat-saturated post-contrast; (B) sagittal PD fat-saturated. Both images show a diffuse infiltrative abnormal signal and thickening of the skin, subcutaneous layer, and muscles of the forearm without a clear margin (arrows). The subcutaneous oedema extends into the arm. Moderate enhancement is seen in the post-contrast sequence (A). MRI of the right forearm: (C,D) at 6 months after treatment started; (C) Coronal STIR; (D) Sagittal T1 fat-saturated post-contrast. Both images show a resolution of the abnormal changes.
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F2
The MRI of the right forearm demonstrated a diffuse infiltrative lesion that crossed multiple planes in the forearm without a clear margin (Figures 2A,B), and the ultrasound doppler confirmed the lesion to be a high-flow vascular tumor (Figure 1B). A repeat MRI after 6 months of treatment revealed a complete resolution of the lesion (Figures 2C,D); however, clinically, there was some residual skin discoloration.
(A) The right upper limb shows a resolution of discoloration and swelling after 1 year of oral sirolimus. (B) The girl's current photograph of her right upper limb at 3 years of age.
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F3
After the completion of the dosage of 1 year of oral sirolimus, the right upper limb swelling and discoloration resolved completely (Figure 3A). Currently, at the age of 3 years, she remains in remission (Figure 3B).