Hyponatremia and hypochloremia may also be caused by lung cancer

Aunt Wang is 58 years old this year. She never imagined that what she thought was indigestion would turn into undifferentiated small cell lung cancer. It was all like a nightmare.

Last month, Aunt Wang, who had a good appetite, suddenly couldn't eat. She felt upper abdominal discomfort, bloating, and occasional nausea. Thinking it was indigestion, Aunt Wang didn't take it seriously and only received symptomatic treatment at the community hospital. As a result, the symptoms did not improve at all, but worsened. She always felt weak all over, so she rushed to a large hospital.

Blood biochemistry test in the outpatient clinic showed: sodium 118.2mmol/L, chloride 81.9mmol/L, urea nitrogen (BUN) 1.99mmol/L. The doctor judged it to be electrolyte disorder, hyponatremia and hypochloremia. After admission, the patient was given fluid and electrolyte supplementation. One week later, the blood sodium and chloride levels were still low, the urine sodium was 244mmol/L, and the urine chloride was 272mmol/L.

Physical examination: poor skin elasticity, no superficial lymph nodes, centered trachea, normal auscultation of the heart and lungs, soft abdomen without tenderness, liver and spleen not palpable. Chest X-ray showed a mass shadow in the left hilum, CT diagnosed left lung cancer, and fiberbronchoscope pathological biopsy diagnosed undifferentiated small cell lung cancer.

The doctor told Aunt Wang that about 26% of small cell lung cancer cases have endocrine abnormalities, of which only 5% have clinical symptoms. Many patients can reduce or disappear the extrapulmonary manifestations after the tumor is removed. After the tumor was removed surgically, Aunt Wang's digestive system symptoms gradually disappeared, and the reexamination of blood sodium, blood chloride and 24-hour urine sodium and urine chloride also returned to normal.