Tumors of the diaphragm.

Primary tumors of the diaphragm are rare, and more than half are benign. Diaphragmatic tumors arise from mesenchymal tissue because of their mesodermal origin, and all varieties of these tumors have been reported. An interesting paraphenomenon is hypertrophic osteoarthropathy, most commonly seen in tumors of neurogenic origin. In most instances, these tumors are small and can be excised with a primary repair anticipated. Secondary involvement of the diaphragm from lung cancer is more common, but is rarely associated with a resectable lesion. Direct extension from other intra-abdominal or intrathoracic tumors can occur, commonly from mesothelioma, lung cancer, and hepatic carcinoma. In some cases, en bloc excision of the diaphragm is required, and in many instances diaphragmatic replacement is necessary using a variety of thin plastic prostheses, if a wide resection is required. Attempts at primary repair under tension, especially on the left side, may lead to diaphragmatic rupture and herniation.