Metastatic malignant solitary fibrous tumor of urinary bladder

We report a case of a primary malignant solitary fibrous tumor (SFT) of the urinary bladder in a previously healthy 35-year-old male. The unusual presentation, focal GATA3 expression in the biopsy and the excessive rarity of the entity at the involved location all contributed to a challenging diagnosis, which was finalized with the resection specimen. Review of the literature highlighted the rarity of this tumor but revealed a relatively positive outcome, with no previous reports of disease recurrence. We therefore describe the first report of malignant bladder SFT associated with pulmonary metastases.