Randall plaque versus renal stone?

A 43-year-old patient has just left the office. Her primary care physician had dutifully evaluated her recent complaint of vague abdominal pain with an abdominal ultrasound. The multiple, small, punctate hyperechoic lesions in the kidney were deemed concerning for renal calculi and an abdominal computed tomography (CT) scan was ordered to better delineate these " renal stones ". The CT report revealed " multiple bilateral punctate calcifications consistent with possible nephrolithiasis versus nephrocalcinosis, " and the patient was referred to urology clinic for further evaluation. In our clinic the patient was interviewed and examined and the scan was carefully reviewed. The patient denied symptoms of renal colic and physical examination demonstrated no costovertebral angle tenderness. No hydronephrosis or evidence of urinary obstruction could be seen on the scan, and we provided a diagnosis of Randall plaques and nephrocalcinosis. The patient was reassured that there were no stones to treat and there was no need for surgery. General lifestyle and dietary modification counseling for stone prevention were provided, and the patient was discharged from our clinic, happy with her benign diagnosis. But is such a diagnosis benign? Recent data suggests that a single CT scan may significantly increase a woman's lifetime risk of developing breast cancer. The repeated scanning that is often the mainstay of observation or conservative management of renal stones can result in a cumulative dose of radiation equivalent to that of survivors of Hiroshima's atom bomb. Furthermore, up to 2% of cancers in the United States today might be attributable to radiation related to CT scanning (1). We would argue that having a Randall plaque diagnosed as a renal stone is not so benign a designation and propose that it is time to redefine the delineation between the two. The core question can be simply put-what is the true difference between a Randall plaque and a renal stone, and how can we differentiate the two before patients are subjected to unnecessary diagnostic tests? To frame the argument, consider the work of Alexander Randall and the ways in which data from his landmark findings could be exploited. In his original autopsy studies Randall noted that 17% of the nearly 500 kidneys had sub-epithelial plaques at the tip of the renal papilla (2). This knowledge can be used as a means to achieve a variety of ends, and these odds may seem quite attractive to patients seeking secondary gain from …