+ General Considerations

• Epithelial tumors, in particular TCC, are the most common tumors of the urinary bladder and account for up to 92% of feline bladder tumors
• Other urinary bladder tumors include SCC, ADC, rhabdomyosarcoma, FSA, CSA, leiomyosarcoma, HSA, chemodectoma, and benign tumors such as leiomyoma and fibroma

+ Transitional Cell Carcinoma

• Dogs excrete large quantities of tryptophan metabolites in the urine
• However, cats metabolize tryptophan differently and do not excrete urinary tryptophan metabolites

Location

• TCC are either diffuse or located in the fundus or ventral bladder wall in cats
• TCC are most frequently located in the trigonal area in dogs resulting in urinary tract obstruction

+ Clinical Signs

• Dysuria, hematuria, pollakiuria, and stranguria
• Vaginal discharge
• Urinary obstruction
• Incontinence
• Urinalysis and Urine Sediment Cytology

+ General Considerations

• Hematuria and proteinuria are consistent findings on urinalysis due to ulceration of the urothelial mucosa
• Bacteruria, pyuria, and positive urine cultures are common in cats
• Bladder wash cytology may improve diagnosis capabilities by reducing contaminants

+ Urine Sediment Cytology

• Neoplastic transitional cells are difficult to differentiate from reactive transitional cells
• Mesenchymal tumors exfoliate poorly and are rarely diagnosed with analysis of urine sediment

+ Blood Tests

• Hematology and serum biochemistry findings are usually normal or non-specific
• Mild to moderate normochromic, normocytic anemia can be caused by either hematuria or bone marrow suppression secondary to chronic disease
• Uremia may result from neoplastic obstruction of urinary outflow or age-related renal failure

+ Survey Radiographs

• Magining techniques include survey abdominal and thoracic radiographs, contrast radiography, and CT
• Survey radiographs: sublumbar lymph node enlargement, renomegaly, and metastatic disease in the pulmonary parenchyma or skeleton, particularly lumbar vertebrae and pelvis
• Positive contrast cystography is useful for identification of mucosal abnormalities and space occupying lesions
• Excretory urogram is indicated to determine the location and extent of obstructive urinary tract disease when the urethra cannot be catheterized

+ Ultrasonography

• Recommended to determine the location and extent of bladder involvement, regional lymph node size and appearance, and involvement of adjacent anatomical structures such as the colon
• Superior to excretory urography and double-contrast cystography in detecting TCC

+ Biopsy

• Required for definitive diagnosis of urinary tract tumors
• Techniques include FNA, needle biopsy, catheter biopsy, cystoscopic, and open surgery
• Percutaneous biopsy procedures are not recommended due to the risk of tumor seeding
• Inflammation secondary to necrosis and ulceration is common and may result in false-negative findings

+ Surgery

• Surgical techniques for management of bladder tumors include:
• Palliative procedures: tube cystostomy ± partial cystectomy
• Curative-intent procedures: partial cystectomy and total cystectomy with urinary diversion
• Cystostomy tube can be placed percutaneously or with either laparoscopic or open surgery
• Complications: stranguria, pollakiuria, hematuria, urine leakage around the stoma, and vesicoureteral reflux which predisposes to ascending UTI and tumor seeding of the upper urinary tract

+ Adjunctive Management

Role of chemotherapy and radiation therapy is unknown