2026 Hypokalemia associated to neuroendocrine carcinoma of the cervix

• Published in: Nephrology, dialysis, transplantation Vol. 39; no. Supplement_1
• Main Authors: González, David Menéndez, Rosado, Consolación, Cornejo, Gilda Carreño, Felipe, Maria Carmen, Manzanedo, Rosario, Jiménez, Miguel Ángel Navas, Garcia, Jesus Martin
• Format: Journal Article
• Language: English
• Published: 23.05.2024
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfae069.1799

Abstract Background and Aims Hypokalemia is one of the most common electrolyte disorders seen in clinical practice. Hypokalemia can be caused by decreased intake of potassium, redistribution of potassium (K+) in cells or by excessive gastrointestinal losses or renal losses. In this setting, hypokalemia may also be caused by the paraneoplastic production of ectopic adrenocorticotropic hormone (ACTH) by some tumors. Cancer of the uterine cervix is the fourth common cancer affecting women worldwide and the fourth most common gynecologic cancer in Spain. Neuroendocrine carcinoma of the cervix represents about 2% of all cervical neoplasms. Method We report the case of a 44-year-old Peruvian woman with hypokalemia who was diagnosed with Cushing syndrome secondary to paraneoplastic production of ACTH by neuroendocrine carcinoma of cervix. Results Patient was overweight and affected by uterine myoma and anemia without further investigations. She was admitted to our hospital due to lower back pain, leg swelling and constipation. Blood pressure was normal, chest radiography did not show abnormal findings and ECG showed the U wave. Laboratory tests at admission revealed hypokalemia (2.3 mmol/L), metabolic alkalosis, anemia (hemoglobin 9.5 g/dL), hyperkaliuria (K+ urine/Creatinine urine 70 mmol/g) with an elevated transtubular potassium gradient (TTKG=12) and normal renal function. Laboratory data are presented in Table 1. She developed hypertension in the first day of hospitalization. Renin, aldosterone and cortisol tests was performed. Hypercortisolism was observed and confirmed with 24-hour urinary cortisol excretion. Because of an elevated ACTH (263 pg/mL), pituitary magnetic resonance imaging was performed without lesions. Whole-body computed tomography revealed a cervical mass. PET scan showed pelvic, adrenal, hepatic and local lymphadenopathy activity (see Fig. 1). After the histopathological study, diagnostic of small cell neuroendocrine carcinoma of the cervix was made. Chemotherapy therapy was initiated with cisplatin/etoposide regimen. The patient decide to return to Peru because of the poor prognosis of her illness. At discharge, potassium level was 3 mmol/L despite the treatment with spironolactone, ramipril, losartan and oral potassium chloride (160 mmol). Conclusion Hypokalemia is a common clinical disorder. In some patients it may be caused by an increased mineralocorticoid activity due to ectopic ACTH-secreting tumors. Applying diagnostic algorithms to electrolyte disorders, beyond their simple treatment, can unmask secondary causes and serious diseases.