A child with persistent low-grade fever, urinary frequency, and hypertension: Questions

Excerpt

A 12-year-old male presented with intermittent low-grade fever (100 to 101°F), anorexia, fatigue, muscle aches, and increased frequency of urination for a couple of months. There was no obvious history of polydipsia. In this period, he lost 3 kg (current weight for age was < −2 standard deviations). He was also noted to have high blood pressure classified as stage II hypertension. Fundoscopy showed retinal arterial attenuation. Echocardiography was normal. Polyuria was documented (urine output 4500 mL per 24 h, i.e., 2.5 L/m²/day) and urine analysis showed 16–18 pus cells and 6–8 red blood cells per high power field with early morning urinary specific gravity of 1010. Urine culture was sterile. Fasting blood sugar was normal; creatinine was mildly elevated (0.94 mg/dL); calcium was grossly elevated (16.7 mg/dL); and other electrolytes, including blood gas analysis, were normal. Ultrasound showed bilateral enlarged kidneys with slightly raised echogenicity and normal Doppler study. Vitamin D3 {25 (OH)} was normal; parathormone (iPTH) was low (4.78 pg/mL); and 1,25 (OH) vitamin D3 (calcitriol) was high (120 pg/mL). Urinary spot calcium creatinine ratio was elevated (0.44 mg/mg). Thyroid hormones and early morning cortisol level were within normal range. Chest X-ray was reported normal. Magnetic resonance imaging (MRI) of the abdomen (Fig. 1) revealed bilateral enlarged kidneys with focal nodular rounded lesions and enlarged abdominal lymph nodes (Fig. 1). Thyroid function and angiotensin-converting enzyme levels were normal. Tuberculin skin test was strongly positive but both sputum and urine failed to reveal any evidence of tuberculosis even on cartridge-based nucleic acid amplification test (CBNAAT).

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