[Hyponatremia as a presenting sign of metastatic disease in muscle invasive bladder cancer.]

Bladder cancer is a commonly diagnosed malignancy in Europe, being 30% muscle-invasive at diagnosis. In these patients, metastases can develop both at diagnosis and after progression. Metastatic disease can manifest in a number of different ways, even as hydroelectrolytic alterations. In this work, we go through the causes of hyponatremia in patients suffering from bladder cancer and its relationship with disseminated disease.

We present two cases of patients with muscleinvasive bladder cancer with a common electrolytic misbalance, hyponatremia.

As a result of the study, bone and cerebral metastases were revealed.

The electrolytic alterations in the oncologic patient can have several causes: chemotherapy, urinary diversion, pain, or even to the tumor itself or its metastases. It is necessary to conduct an exhaustive study in order to discard the most important causes of hyponatremia and be able to decide an appropriate treatment.

Archivos espanoles de urologia. 2018 Nov [Epub]

Paola Calleja, Mario Domínguez, Enrique Ramos, César Jesús Carrión, Guillermo Velilla, José Luis Gutiérrez

Servicio de Urología. Hospital Universitario Marqués de Valdecilla. Santander. España.