[Mucoid pseudo-cysts of the sheath of the external popliteal sciatic nerve. Apropos of 2 cases].

Two cases of paralysis of the etxernal popliteal sciatic nerve are described. They are secondary to the development of a pseudo-cyst containing mucoid matter within the connective tissue sheath of the nerve itself. The authors describe the pathological anatomy of these lesions and discuss their aetiology, favouring the theory of mucoid degeneration of the connective tissues of the nerve sheath. They give brief indication of the clinical symptoms and emphasize the need for early but simplified surgery, ruling out any nerve resection.