[Large solitary fibrous tumors of the pleura as incidental finding. 2 case reports of a rare tumor entity].

The solitary fibrous tumor (SFT) is a very rare and usually benign neoplasm. This tumor is mostly located in the thoracic cavity, but it has also been reported in numerous sites including liver, skin, and meninges. Due to its rarity diagnosis is often difficult. Accordingly, histopathological differentiation is of major importance. Solitary fibrous tumors consistently express CD 34 and react negatively to epithelial markers. This absence of expression of epithelial markers, especially cytokeratin, is also useful to distinguish these rare entities from sarcomatous mesotheliomas. The treatment of choice for solitary fibrous tumors is extensive surgical resection. Up to now there is no evidence that radiation and chemotherapy are effective. The local recurrence or onset of metastases depends on histologic parameters. In cases of benign classification (60-80%), the recurrence rate was only 2% after surgical excision. One-half of the patients with malignant tumors can be cured; the rest develop recurrences and metastases more often. Especially in those cases, emphasis should be placed on continual follow-up examination. We report two cases of a 65- and a 75-year-old male patient with huge intrathoracic solitary fibrous subpleural tumors, discovered incidentally on routine chest X-ray.