[Periarteritis nodosa associated with lung cancer. A new observation].

The cases of vasculitis associated to malignant tumour are uncommon, their course which is often parallel suggests a direct link between them. We report the observation of periarteritis nodosa associated with a lung cancer discovered in the following of vasculitis; whereas the course is favorable in 83 years old man without particular history. The frequency of neoplasia with vasculitis is estimated between 3 and 8%, and periarteritis nodosa can't be a paraneoplastic syndrome. Lung and colic tumours are the most frequent reported of the solid tumours. The delay of appearance of vasculitis varies from 25 months before to 9 months after cancer diagnosis. There are many factors, either some treatment, the neoantigens involve the formation of immune complexes, lymphokines and some vasoactive substances.