Uroplakin II

Formalin-fixed, paraffin embedded tissue block or cell block, or 1 unstained charged slide for each test requested plus 3-4 additional unstained slides cut at 4 microns. Adequate space on each slide for control tissue is required.

Uroplakin II is a 15 kDa protein component of urothelial plaques, which enhances the permeability barrier of the urothelium. It is a fairly specific marker for urothelial differentiation and may be included in the antibody panel for carcinoma of unknown primary when urothelial carcinoma is in the differential diagnosis. The major drawback is its lower sensitivity, but the newer uroplakin II antibody is said to carry a better sensitivity than the older uroplakin III.