Primary leiomyosarcoma of the lung.

Primary smooth muscle tumors of the lung are rare, and usually arise from the uterus, gastrointestinal tract, or soft tissue. The patient reported was found at autopsy to have leiomyosarcoma which arose in the left mainstem bronchus and metastasized to the right lung, liver, pancreas, both kidneys, and brain, sparing the lymphatic system. This tumor is slow growing and late metastasizing, in spite of its degree of anaplasia, and has a better prognosis for surgical cure than does bronchogenic carcinoma. S ha v et aP found 26 cases of primary leiomyosarcoma of the lung reported up to 1961 and added two more. We report another case of primary leiomyosarcoma of the lung with multiple metastases, diagnosed at autopsy.