Solitary fibrous tumor of the urinary bladder associated with a high-grade urothelial invasive carcinoma. A case report A. Pitino * , S. Squillaci, C. Spairani, M. Ferrari, M. F. Cosimi, W. Fusco, C. Rossi, F. Montefiore, G. L. Bigatti, V. La Paglia * San Giacomo Hospital, Division of Anatomic Pathology, Novi Ligure, Italy