Presentation is often insidious, and a large proportion (50%) of patients may be asymptomatic at the time of detection 1. Alternatively, as these tumors can produce large quantities of mucus, patients may present with bronchorrhea. [radiopaedia.org]

Evaluation of asymptomatic microscopic hematuria in adults: the American Urological Association best practice policy--part II: patient evaluation, cytology, voided markers, imaging, cystoscopy, nephrology evaluation, and follow-up. [medscape.com]