Recurring thoracal mesenchymoma.

A four-times-recurring thoracal mesenchymoma is presented. Each tumor evolved for 2-5 years before resection, the general evolution of the case being of about 30 years. Histologically, the tumors, which involved the thoracal wall presented at the same time the predominating fibroblasto-fibrocytic structure sometimes forming whirls, different mesenchymal derivatives as vessels and angiomatous formations, osseous trabeculae, chondroblastic areas, and more or less dense zones with leiomyocytes sometimes forming myomatous and myofibromatous aspects. Mitoses and nuclear atypias were very rare. The diagnosis of benign recurring mesenchymoma of the thoracal wall and pleura is discussed.