Hexaminolevulinate is an optical imaging drug. In solution form, it is instilled intravesically for use with photodynamic blue light cystoscopy as an adjunct to white light cystoscopy. After bladder instillation, hexaminolevulinate enters the bladder mucosa and is proposed to enter the intracellular space of mucosal cells where it is used as a precursor in the formation of the photoactive intermediate protoporphyrin IX (PpIX) and other photoactive porphyrins (PAPs). PpIX and PAPs are reported to accumulate preferentially in neoplastic cells as compared to normal urothelium, partly due to altered enzymatic activity in the neoplastic cells. In 2010, FDA granted approval for hexaminolevulinate hydrochloride as an optical imaging agent for cystoscopic detection of non-muscle invasive papillary cancer of the bladder for patients suspected or known to have lesion(s) on the basis of a prior cystoscopy.