Oligomeganephronia with PAX2 gene deletion diagnosed at the third renal biopsy: a case report.

Oligomeganephronia is a congenital anomaly of the kidney and urinary tract. It is often categorized as one of the hypoplastic kidney conditions. The pathological diagnosis of oligomeganephronia is challenged by the absence of clear diagnostic criteria, which often leads to subjective interpretations by pathologists. This report presents the case of a 7-year-old girl who was diagnosed with oligomeganephronia through a third renal biopsy, which was confirmed by gene analysis revealing PAX2 deletion. Two previous renal biopsies, with the naked eye through a microscope, failed to identify glomerular hypertrophy and sparse glomerular distribution density. However, using digital images, the glomeruli were larger than those of age-matched controls, and the number of glomeruli within the renal cortex area revealed sparse glomerular distribution density. Image processing allows for objective evaluation of the glomerular size and glomerular distribution density, providing a quantitative assessment. For earlier diagnosis of oligomeganephronia, an appropriate objective standardized method for measuring glomerular size and glomerular distribution density should be established.