[Localized fibrous tumor in the parenchyma. Report of 2 cases, one of them multiple and bilateral].

Localized fibrous tumor is an uncommon neoplasm that is usually located in the visceral pleura. Histologically these tumors are composed of randomly arranged fascicles or networks of fusiform cells, among which there is a varying amount of collagen. Most authors consider that these cells originate in submesothelial mesenchymal cells. The condition is normally silent, though hypoglycemia, hypertrophic osteoarthropathy or other symptoms sometimes result. The treatment of choice is total resection and imaging techniques are extremely helpful for establishing surgical strategy, even though surgery is often performed before a histopathologic diagnosis is available. We present 2 patients with intrapulmonary fibromas that were histologically identical to localized fibrous pleural tumors. These tumors are rarely found in the parenchyma and multiple bilateral presentation is exceptional, having been described only once in the literature. One of our patients had a single pulmonary node that happened to be noticed on an X-ray. The other had multiple bilateral nodes that required several surgical procedures; the intraparenchymatous location for this type of tumor has not been described to date. We discuss clinical, therapeutic and histopathological aspects of these tumors and review the literature.