An Uncommon Clinical Case with Fanconi Syndrome, Acanthosis Nigricans and Hyperinsulinemia

Abstract

Fanconi syndrome (FS) is a disease of the proximal renal tubules of the kidney in which glucose, amino acids, uric acid, phosphate, and bicarbonate are passed into the urine, instead of being reabsorbed. Laboratory findings are important for the diagnosis such as hyponatremia, hypopotassemia, hypocalcemia, hypophosphatemia, glucosuria, proteinuria, and metabolic acidosis. In this presentation, the patient admitted to the hospital with polyuria, polydypsia, weakness of the extremity muscles, and axiller brown colored cutaneous lesions. Blood and urine laboratory test results were consistent with FS. Besides, hyperglycemia and hyperinsulinemia were determined as an indicator of diabetes mellitus. Axillary skin lesions were described as acanthosis nigricans. This case was presented to point out the coexistence of renal proximal tubule dysfunction, hyperinsulinemia, and acanthosis nigricans as an unusual clinical feature in the literature. J Med Cases • 2013;4(12):831-833 doi: http://dx.doi.org/10.4021/ jmc1587w