The authors describe and discuss the case of patient with paresthesias in the popliteal fossa. On clinical examination, there was a palpable mass in the popliteal fossa suspected of Baker’s cyst or of an entrapment syndrome. Neurological and electromyographic examination were normal. Magnetic resonance imaging showed small solid mass in the popliteal fossa in close contact with the tibial nerve. Signal characteristics gave evidence of benign tumor. Then a surgical exposure of the popliteal fossa was performed that revealed vein varicose dilatation. The histologic diagnosis was compatible with surgery.

        Key words: magnetic resonance imaging – tibial nerve – benign tumor of peripheral nerve – vein varicous dilatation – popliteal fossa