[Posterior interosseous nerve palsy due to lipoma].

A 45-year-old male patient presented with paralysis of slow onset in the right forearm and hand muscles. Electromyographic assessment revealed severe denervation in the muscles innerved by the posterior interosseous nerve. Magnetic resonance imaging demonstrated a tumoral mass compressing the nerve. The patient underwent surgical excision with an initial diagnosis of lipoma. Surgical exploration and a biopsy confirmed the diagnosis. Active wrist movements and digital extension were possible after three weeks and the patient resumed full strength six weeks after the operation.