[Hyponatremia in the course of small cell lung cancer--a case report]

Hyponatremia is a common electrolyte disorder occurring in patients with malignancy. Typically, it runs in the form of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Among malignant diseases it is often ascertained from small cell lung cancer. In the form of paraneoplastic syndrome it may precede clinical and radiological symptoms malignant disease. Hyponatremia requires special attention because of the neurological consequences and the risk of death. We present a case of a patient in whom the occurrence of hyponatremia preceded the appearance of clinical symptoms of lung cancer and has been the reason to start the diagnosis. The normalization of serum sodium was the first signal response to chemotherapy. In contrast, a statement confirmed the recurrence of hyponatremia progression of the disease in the form of metastases to the central nervous system. Speeches hyponatremia refractory symptomatic treatment should be a cause of further investigation into the neoplastic process. Recurrent hyponatremia during or after treatment may suggest its progression. Therefore, monitoring the sodium level is required not only during treatment, but also after the oncological treatment.