Pulmonary osteoarthropathy. Association with mesenchymal tumor metastases to the lungs

Six of 18 patients with sarcomatous tumors metastatic to the lung had hypertrophic pulmonary osteoarthropathy (HPO), and, in three patients in whom tumor regression was achieved by cytotoxic chemotherapy or surgery, the clinical and radiologic changes of HPO were reversed. All six patients had large mass lesions (greater than 5 cm) that impinged on the pleural surface, and the pathophysiologic mechanism resulting in the clinical syndrome of HP may be related to the anatomic relationship of the tumor and the pleura. The use of radionuclide scanning to detect HPO in the absence of roentgenographic signs or clinical symptoms is discussed.