Low-grade papillary uroepithelial carcinoma refers to malignant tumors originating from epithelial tissues; low-grade is its pathologic tissue grading, and papillary is the growth pattern. Epithelial carcinoma is a malignant tumor derived from epithelial tissue. Uroepithelial carcinoma is epithelial carcinoma that occurs in the renal pelvis, ureter, or bladder. The cause of uroepithelial carcinoma is unknown, and known risk factors include smoking and long-term exposure to industrial chemicals. Low-grade papillary refers to the pathologic histologic grading of the tumor; low-grade means that the tumor is well differentiated, and such prognosis is generally better. Those with poor differentiation generally have a poorer prognosis. Papillary means that the tumor grows in a papillary growth pattern. Comparatively, there are carcinoma in situ which is confined to the mucosa and invasive carcinoma which grows infiltratively. Patients are advised to seek medical attention for timely diagnosis and treatment.