Ans. (d) Urinary bladderRef: Bailey & Love 26th ed. /1330-35* Transitional cell epithelium lines -> the urinary tract from the renal pelvis to the ureter, urinary bladder, and the proximal two-thirds of the urethra.* Transitional cell carcinoma-Cancers can occur at any point mentioned above:# 90% of malignancies develop in the bladder# 8% in the renal pelvis# 2% in the ureter or urethra.Salient features about urothelial tumors* Bladder cancer is the fourth (4th) most common cancer in men and the thirteenth (1 +3=4) in women.* Among urothelial tumors-95% are transitional cell in origin.* Others are- Pure squamous cancers with keratinisation constitute 3%, adenocarcinomas 2%, and small cell tumors (often with paraneoplastic syndromes) <1%. Adenocarcinomas* Polychronotropism -urothelial tumors exhibit polychronotropism, which is the tendency to recur over time in new locations in the urothelial tract.* Most imp risk factor- Cigarette smoking* Other- aniline dyes, drugs phenacetin and chlornaphazine, external beam radiation. Chronic cyclophosphamide ,Schistosoma haematobium(a parasite-cause both see and tcc)* Vitamin A - protective.* 3 clinical subtypes-# Superficial (75%)# Invade muscle (20% )# Metastatic (5%)* Clinical presentation# Hematuria (painless)- Most common presentation (80-90% of cases)# Irritative bladder symptoms such as dysuria, urgency, or frequency of urination occur in 20-30% of patients with bladder cancer.* The bladder is the most common source of gross hematuria (40%),* Among bladder causes benign cystitis (22%) > bladder cancer (15%) as a cause of hematuria* Microscopic hematuria- is more commonly of prostate origin (25%)* MC site of lymphatic metastasis: -pelvic lymph nodes (obturator MC)* MC site of hematogenous spread- LIVER > LUNG* Diagnosis- diagnosis and initial staging is made by cystoscopy and TUR.# Newer; voided urine assays (i.e., bladder tumor antigen , NMP-22, fibrin/fibrinogen degradation products ) are being used for the detection and surveillance of urothelial carcinoma.* Management-cystoscopy and TUR or biopsy* Further management depends on stage, grade, size, multiplicity, recurrecnce pattern* Drugs for intravesical chemo- Mitomycin,Thiotepa, Epirubicin,BCG (most effective)