Diagnostic examination of the child with urolithiasis or nephrocalcinosis

Abstract

Urolithiasis and nephrocalcinosis are more frequent in children then currently anticipated, but still remain under- or misdiagnosed in a significant proportion of patients, since symptoms and signs may be subtle or misleading. All children with colicky abdominal pain or macroscopic hematuria should be examined thoroughly for urolithiasis. Also, other, more general, abdominal manifestations can be the first symptoms of renal stones. The patients and their family histories, as well as physical examination, are important initial steps for diagnostic evaluation. Thereafter, diagnostic imaging should be aimed at the location of calculi but also at identification of urinary tract anomalies or acute obstruction due to stone disease. This can often be accomplished by ultrasound examination alone, but sometimes radiological methods such as plain abdominal films or more sensitive non-enhanced computed tomography are necessary. Since metabolic causes are frequent in children, diagnostic evaluation should be meticulous so that metabolic disorders that cause recurrent urolithiasis or even renal failure, such as the primary hyperoxalurias and others, can be ruled out. The stone is not the disease itself; it is only one serious sign! Therefore, thorough and early diagnostic examination is mandatory for every infant and child with the first stone event, or with nephrocalcinosis.

Fig. 1

a Normal, still hyperechoic kidney of a preterm infant; b Tamm–Horsfall kidney; c medullary nephrocalcinosis (NC) grade I (mild increase of echogenicity around the pyramidal border); d medullary NC grade II (mild increase of echogenicity at whole pyramid); e medullary NC grade III (more severe hyperechogenicity of entire pyramid); f diffuse corticomedullary NC [6]