Feline Transitional Cell Carcinoma Study Guide

Overview and Clinical Importance

Transitional cell carcinoma (TCC), also known as urothelial carcinoma, is a malignant neoplasm arising from the transitional epithelium (urothelium) lining the urinary tract. In cats, TCC is the most common malignant tumor of the lower urinary tract and the second most common urinary neoplasia after renal lymphoma. With an estimated prevalence of 0.18%, feline TCC is considerably rarer than its canine counterpart but represents a clinically significant differential diagnosis in older cats presenting with chronic lower urinary tract signs.

Unlike canine TCC, which predominantly affects the trigone, feline TCC demonstrates more variable tumor locations throughout the bladder. This has important implications for surgical management and prognosis. The disease is aggressive, with high rates of local invasion and metastatic potential.

Relevant Anatomy and Histology

Urinary Bladder Anatomy

The feline urinary bladder is divided into three anatomical regions: the apex (cranial blind end), body (middle portion), and neck (funnel-shaped region connecting to the urethra). The trigone is a triangular area on the dorsal aspect of the bladder bounded by the two ureteral openings cranially and the urethral orifice caudally. Unlike dogs, the feline bladder remains consistently cranial to the pubis regardless of distension.