Negative pathology of ureteral carcinoma significantly delaying the diagnosis of the primary tumor of osteoblastic metastases: A case report and review of the literature

Ureteral urothelial carcinoma (UC) is a rare malignant tumor. The most common clinical manifestations of ureteral UC are hematuria, increased urinary frequency, dysuria and pain. The diagnosis of ureteral UC is made via radiography, endoscopy and pathology. Although osteoblastic destruction is usually observed in metastasis of prostate cancer, UC can also be a reason for osteoblastic metastasis. The present study reports the case of a 66-year-old man presenting with osteoblastic metastases, in which the primary tumor was finally diagnosed as a ureteral UC. However, the lack of pathological evidence significantly delayed the diagnosis of the primary tumor (>6 months), even though the results of radiographic examination, and the type and mode of bone metastases significantly suggested a ureteral UC. The case reveals that a suitable screening test should be recommended for patients at high risk due to the possibility of a negative pathology result for ureteral UC. Additionally, a more efficient diagnostic method is required. Moreover, the possibility of new diagnostic criterion that do not rely on the pathology of primary foci in ureteral UC should be considered in future.