This collection of cases describes some unusual urological tumors and complications related to urological tumors and their treatment. Case 1: A case of uretero-arterial fistula in a patient with long-term ureteral stenting for ureteral oncological stricture and a second case associated to retroperitoneal fibrosis were described. Abdominal CT, pyelography, cystoscopy were useful to show the origin of the bleeding. Angiography is useful for confirming the diagnosis and for subsequent positioning of an endovascular prosthesis which represents a safe approach with reduced post-procedural complications. Case 2: A case of patient who suffered from interstitial pneumonitis during a cycle of intravesical BCG instillations for urothelial cancer. The patient was hospitalized for more than two weeks in a COVID ward for a suspected of COVID-19 pneumonia, but he did not show any evidence of SARS-CoV-2 infection during his hospital stay. Case 3: A case of a young man with a functional urinary bladder paraganglioma who was successfully managed with complete removal of the tumor, leaving the urinary bladder intact. Case 4: A case of a 61 year old male suffering from muscle invasive bladder cancer who was admitted for a radical cystectomy and on the eighth postoperative day developed microangiopathic hemolytic anemia and thrombocytopenia, which clinically defines thrombotic microangiopathy.