Unexpected Discoveries: Uncovering Incidental Tumors in Simple Nephrectomy Specimens

Objectives

We aimed to evaluate the characteristics of patients with incidental kidney tumors detected in the pathological examination performed after simple nephrectomy due to a non-functioning kidney.

Patients and methods

The pathology results of nephrectomy specimens from patients who underwent simple nephrectomy with the diagnosis of non-functioning kidney between January 2012 and March 2021 were retrospectively analyzed. Data regarding demographic information, imaging methods, and clinical and histopathological features of the patients were collected. The number of patients with incidental renal tumors was determined.

Results

A total of 163 patients with nonfunctioning kidneys who underwent simple nephrectomy between January 2012 and March 2021 were included in the study. Sixty-nine (42.3%) patients were male and 94 (57.7%) patients were female. The most common complaint was flank pain (60.7%). The cause of the nonfunctioning kidney was urinary stones in 116 (71.2%) patients and ureteropelvic/ureterovesical junction stenosis in 21 (10.1%) patients. Incidental renal tumors were detected in 21 (12.9%) patients. Papillary adenoma was the most common renal tumor and was detected in 11 patients. Four patients had renal cell carcinoma and 4 patients had urothelial cell carcinoma (UCC). Three of the patients with UCC had high grade invasive UCC with squamous differentiation and 1 patient had low grade papillary UCC.

Conclusion

In non-functioning kidneys, kidney tumors may be overlooked due to radiological and clinical diagnostic difficulties. Therefore, careful macroscopic and microscopic histopathological evaluation is necessary to detect incidental renal tumors.