Hypertrophy of kidney

This code signifies an abnormal enlargement or overgrowth of kidney tissue. It refers to an increase in the size of the kidney(s) due to an increase in the size of its cells, rather than an increase in the number of cells. This condition can affect one or both kidneys.

Assign this code when documentation specifies hypertrophy of the kidney, often as a compensatory mechanism in cases of renal agenesis, nephrectomy of the contralateral kidney, or chronic kidney disease. It is also applicable when imaging studies or pathology reports confirm an increase in kidney size without evidence of tumor or hydronephrosis.

• Differentiate from hydronephrosis (591) or renal mass/neoplasm, which involve different etiologies and coding.
• Ensure documentation clearly states "hypertrophy" and not simply "enlarged kidney" without further specificity, as "enlarged" can be vague.
• Consider sequencing this code as a secondary diagnosis if the hypertrophy is a consequence of another primary renal condition.