Rationale: Limited knowledge is available regarding solitary fibrous tumors (SFTs), about 15% of which are malignant. In particular, the long-term survival of patients with malignant SFTs (mSFTs), the disease course, and the potential for recurrence of second primary tumors or distant metastases are largely undetermined.
Patient concerns: We report a rare case in which an mSFT was found at the main bronchus of the right lung of a 37-year-old man.
Diagnosis: The tumor cells of mSFT were spindle-shaped and expressed antigen Ki-67, B-cell lymphoma 2, cluster of differentiation 31, and vimentin.
Interventions: A total pneumonectomy was performed.
Outcomes: The patient developed fibrosarcoma of the small intestine at 6 months, as well as extensive pleural and peritoneal metastases at 1 year, after removal of the primary mSFT from the right main bronchus.
Lessons: From these findings, we expect that patients with primary mSFT, especially of the lung, have a high potential to develop second tumors or distant metastases. Close monitoring after surgery is necessary to improve the outcomes of these patients.