[A case of sweet taste perception caused by lung cancer-related hyponatraemia]

Ageusia is known to occur in patients with lung cancer. The type of dysgeusia resulting in all food tasting sweet is, however, rare.

We describe the case of a 70-year-old woman presenting with an unpleasant sweet taste perception as the initial and only symptom of hyponatraemia. It was caused by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion secondary to a small cell carcinoma of the lung. Treated by fluid restriction alone, the plasma sodium concentration increased and the sweet taste perception resolved. The exact pathophysiologic mechanism resulting in this type of dysgeusia is unclear to date.

It is important to be alert when the medical history reveals a relatively rare dysgeusia or ageusia; this could indicate a potentially serious underlying condition, including hyponatraemia caused by SIADH associated with a pulmonary malignancy.