Aldosterone Producing Adenoma Associated Hypercalcemia and Rhabdomyolysis

    

    

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Discussion

Hypokalemia is generally associated with neuromuscular symptoms and acid-base disorders. Potassium depletion from any cause may produce muscle weakness, but hypokalaemic rhabdomyolysis is a rare presentation of hypokalaemia. Rhabdomyolysis from any cause lead to increase in free ionised calcium in the sarcoplasm. This increased sarcoplasmic calcium initiates a series of complex intracellular processes leading to the clinical manifestation of rhabdomyolysis [2].

On initial assessment, our patient presented with rhabdomyolysis including weakness of lower limbs, increased creatinine phosphokinase and mild tubulopathy including polyuria and hypokalaemia. The severity of rhabdomyolysis varies from an asymptomatic increase in creatinine phosphokinase to severe complications such as acute renal failure [2] Tubulopathy might be secondary to hypokalaemia or rhabdomyolysis in our patient. Rhabdomyolysis may cause renal tubular damage and tubulopathy either by free radical mediated injury or directly by effect of lipid peroxidation on tubular cells. Chronic hypokalaemia can also induce tubulointerstitial damage consisting of vacuolization of epithelial tubular cells and interstitial fibrosis; called as hypokalaemia nephropathy, which is quite rare [3].

Aldosterone producing adrenocortical tumors are usually benign (adenoma) and adrenocortical carcinomas constitute less than 0.2% of all childhood neoplasms [4]. This differentiation between adenoma and carcinoma is important for prognosis, but is not always easy. MRI has been proposed to have diagnostic value for this differentiation [5].

Primary hyperaldosteronism due to an aldosterone-secreting adenoma associated with hypokalaemia and rhabdomyolysis has been reported in only few adults [6,7]. Samanthi A et al. [6] reported a 42-year-old hypertensive patient who developed acute onset paraparesis and rhabdomyolysis induced by severe hypokalaemia diagnosed an aldosterone-producing adenoma. Hypertension is unusual in children and endocrine causes are very rare, but primary hyperaldosteronism should always be considered in the differential diagnosis [8-10]. Recently, Karaguzel et al [11] Reported a 14 year old girl with primary hyperaldosteronism due to unilateral aldosterone producing adenoma who developed rhabdomyolysis following hypokalaemia. Primary hyperaldosteronism due to an adrenal tumor is rare in childhood; however, it should be considered in the presence of hypokalaemia in a hypertensive child with normal renal function, even if the clinical presentation is unusual, such as severe rhabdomyolysis, of which early recognition is crucial for interventions directed to preserve renal function.

References

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