Perineural spread of tumour

Patient is post-operated case of spindle cell neoplasm of calf.
An altered signal intensity lesion, measuring approx. 35 x 32 x 55mm (AP x TRA x CC) is seen in the proximal calf region, approx. 10cm from the knee joint, between the tibia and fibula. It is infiltrating the tibialis posterior muscle. Posterior tibial nerve is seen at the posteromedial aspect of the lesion. Mild splaying of surrounding muscles is seen.
Another smaller lesion measuring approx.. 13 x 7 x 25mm (TRA x AP x CC) is seen inferior to the above lesion. It is compressing the posterior tibial nerve.
Posterior tibial nerve appears thickened and hyperintense distal to this lesion.
No obvious cortical breach / marrow infiltration of tibia / fibula seen.

• Altered signal intensity lesion in the proximal calf region, approx. 10cm from the knee joint, between the tibia and fibula infiltrating the tibialis posterior muscle. Posterior tibial nerve is seen at the posteromedial aspect of the lesion.
• Another smaller lesion measuring is seen inferior to the above lesion, compressing the posterior tibial nerve.
• Posterior tibial nerve appears thickened and hyperintense distal to this lesion.

Findings are suggestive of recurrent lesions with possible perineural spread.