Presentation
Right mid-foot dorsum lump for a few years. Recent mild local discomfort.
Patient Data
A well-defined lesion with echogenic striations with mild compressibility. No internal calcification/ cystic changes/ vascularity. It measures about 43 x 26 x 10 mm. The extensor hallucis brevis muscle lies on the medial side of the lesion, with its rim covering the anterior of the lesion favoring the intramuscular lesion location (claw sign). The extensor digitorum brevis muscle is normal and lies on the lateral side of the lesion. The extensor digitorum longus tendons pass superficial to the lesion. The patent dorsalis pedis artery lies medial and deep to the lesion.
Dorsal mid-foot bulge with fat density. Normal bones and joints.
Case Discussion
The foot dorsum lump shows ultrasound features of a lipoma. A claw sign favors intramuscular location involving the extensor hallucis brevis muscle.