Presentation
Atraumatic origin of left calf pain, and oedema for the last few days. Referred to rule out/rule in left lower limb deep venous thrombosis.
Patient Data

Cyst in the posteromedial knee and calf. Cyst neck passes between the semimembranosus and medial head of the gastrocnemius tendons. Caudal extension of the cyst in the medial head of the gastrocnemius muscle belly. The cyst is filled with internal avascular echoes. Size is about 180 (craniocaudal) x 54 (width) x 20 (anteroposterior) mm. Subcutaneous oedema in the calf. Suprapatellar moderate effusion.
No deep venous thrombosis (images not uploaded).
Case Discussion
The case shows an intramuscular extension of the Baker's cyst in the medial head of the gastrocnemius.