Transitional cell carcinoma

Transitional cell carcinoma (TCC, also urothelial cell carcinoma or UCC) is a type of cancer that typically occurs in the urinary system: the kidney, urinary bladder, and accessory organs. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. It is the second most common type of kidney cancer, but accounts for only 5% to 10% of all primary renal malignant tumors.

TCC arises from the transitional epithelium, a tissue lining the inner surface of these hollow organs.

When the term "urothelial" is used, it specifically refers to a carcinoma of the urothelium, meaning a TCC of the urinary system.

Signs and symptoms
Signs and symptoms depend on the location and extent of the cancer: see for example Bladder cancer.

Causes

 * 1) certain drugs such as cyclophosphamide and phenacetin are known to predispose to bladder TCC.
 * 2) long-term usage of analgesics
 * 3) radiation exposure
 * 4) somatic mutation such as deletion of Chromosome 9p,9q,11p,17p,13q,14q and over expression of RAS (oncogene) and epidermal growth factor receptor (EGFR)
 * 5) cigarette smoke
 * 6) naphthylamines and aniline dyes

Pathology
TCCs are often multifocal, with 30-40% of patients having more than one tumor at diagnosis. The pattern of growth of TCCs can be papillary, sessile (flat) or carcinoma-in-situ (CIS).

The most common site of TCC metastasis outside the pelvis is bone (35%); of these bone metastases, 40% are in the spine.

Terminology
Transitional refers to the histological subtype of the cancerous cells as seen under a microscope.

Classification
The 1973 WHO grading system for TCCs (papilloma, G1, G2 or G3) is most commonly used despite being superseded by the 2004 WHO grading (papillary neoplasm of low malignant potential (PNLMP), low grade and high grade papillary carcinoma).

Treatment
Transitional cell carcinoma (TCC) can be very difficult to treat. Treatment for limited stage TCC is surgical resection of the tumor, but reoccurrence is common. Chemotherapy for TCC consists of the MVAC regimen (methotrexate, vinblastine, adriamycin and cisplatin). TCC can also be treated with infusions of BCG into the bladder.

Associations
It is associated with phenacetin, aniline dyes, cyclophosphamide and those who drink excessive alcohol. It is also associated with hereditary nonpolyposis colorectal cancer.

Prostate
TCC can also be associated with the prostate.