We report a rare pleural solitary fibrous tumor with bullae. Chest computed tomography showed a nodular lesion with bullae adjacent to the left diaphragm. Thoracoscopic resection followed by a pathology study showed that the tumor was a solitary fibrous tumor beside the visceral pleura. We suggest that the bullae containing dilated bronchioles were caused by a check-valve mechanism next to the microinvasive component in the solitary fibrous tumor.
Most localized fibrous tumors arise from the visceral pleura on a stalk and project into the pleural cavity in a pedunculated manner. The origin of the tumors is now believed not to be mesothelial but rather submesothelial, based on studies using conventional histology, immunohistochemistry, and ultrastructural analysis. While inward tumor growth into the lung parenchyma with attachment to the pleura is uncommon, the tumor with an entirely pulmonary location is extremely rare. We present here a rare case of entirely intrapulmonary localized fibrous tumor (ie, localized fibrous tumor of the lung), and we review the pertinent literature.
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.