Dual Diagnostic Dilemma: Gitelman Syndrome and Incidental Neuroendocrine Tumor in a Young Adult With Refractory Hypokalemia

TL;DR

A young man with Gitelman syndrome and a pancreatic tumor faced severe hypokalemia, highlighting the challenges of managing two rare conditions together.

Contribution

This is the first documented case of Gitelman syndrome coexisting with a metastatic pancreatic neuroendocrine tumor.

Findings

The patient had severe refractory hypokalemia, metabolic alkalosis, and hypomagnesemia consistent with Gitelman syndrome.

A metastatic pancreatic neuroendocrine tumor was identified, complicating treatment and management strategies.

The case emphasizes the need to consider malignancy in persistent electrolyte abnormalities and the challenges of advanced therapies in underdeveloped nations.

Abstract

We report the first documented case of Gitelman syndrome coexisting with a metastatic pancreatic neuroendocrine tumor in a 19-year-old male, presenting with severe refractory hypokalemia (K⁺ 1.4-1.7 mmol/L), metabolic alkalosis, and hypomagnesemia. The patient's diagnostic workup revealed inappropriate renal potassium wasting (urinary K⁺ 42 mEq/L), hypocalciuria (urinary Ca²⁺/creatinine ratio <0.1), and elevated fractional chloride excretion (>1%), confirming the diagnosis of Gitelman syndrome. Imaging studies identified a somatostatin receptor-positive Grade 2 pancreatic neuroendocrine tumor (Ki-67 8%) with hepatic metastases, making surgical resection unfeasible. Management comprised high-dose potassium and magnesium supplementation, amiloride, octreotide, and everolimus. On account of disease advancement, initial treatment approaches failed, and peptide receptor radionuclide therapy remained limited for the patient owing to financial constraints. Both Gitelman syndrome and metastatic pancreatic neuroendocrine tumor posed unique challenges that required a coordinated multidisciplinary approach. This case highlights the need for malignancy to be added to the differential diagnosis of persistent electrolyte anomalies. Moreover, it emphasizes the limitations in managing double disease entities in a young individual and the insurmountable hurdles for advanced treatments like peptide receptor radionuclide therapy in underdeveloped nations. This report highlights the importance of further studying the association between the interplay of genetic syndromes (such as Gitelman syndrome) and associated neoplasms, as well as the vital coordination of complex and multidisciplinary management in rare clinical situations.

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