Resection of a giant, invasive malignant solitary fibrous tumor of pleura.

Solitary fibrous tumor of pleura (SFTP) is a rare mesenchymal neoplasm that most commonly involves the pleura, is probably derived from fibroblasts, and has no relationship to malignant mesothelioma. Here, we report a case of complete resection of a giant malignant SFTP. A 61-year-old woman developed fever and left flank pain. Computed tomography revealed the tumor to be 13 cm in size and located in the left thoracic cavity, directly invading the left lower lobe of the lung. The patient underwent radical resection and left lower lobectomy. Immunohistochemical examination revealed a dense proliferation of spindle-shaped cells with ovoid nuclei and collagen fibers hyperplasia. The cells were positive for CD34 and vimentin, and were negative for cytokeratin AE1/AE3, calretinin, S-100 and smooth muscle α-actin. SFTPs have malignant potential, as 20-30 % of resected SFTPs reportedly contain malignant components. Careful long-term clinical follow-up is therefore required for all cases of SFTP.