A Caucasian Man With a Right Renal Mass

This case was prepared by Marc C. Smaldone, MD, MSH, Associate Professor of Urologic Oncology, Department of Surgery-Fox Chase Cancer Center, Temple University Health System, Philadelphia.References1. Purysko AS, Westphalen AC, Remer EM, et al. Imaging manifestations of hematologic diseases with...

Submit your diagnosis to see full explanation.

This case was prepared by Marc C. Smaldone, MD, MSH, Associate Professor of Urologic Oncology, Department of Surgery-Fox Chase Cancer Center, Temple University Health System, Philadelphia.

References

1. Purysko AS, Westphalen AC, Remer EM, et al. Imaging manifestations of hematologic diseases with renal and perinephric involvement. Radiographics. 2016;36:1038-1054. doi: 10.1148/rg.2016150213.

2. Campbell S, Uzzo RG, Allaf ME, et al. Renal mass and localized renal cancer: AUA guideline. J Urol. 2017;198:520-529. doi:10.1016/j.juro.2017.04.100.

3. Johnson DC, Vukina J, Smith AB, et al. Preoperatively misclassified, surgically removed benign renal masses: a systematic review of surgical series and United States population level burden estimate. J Urol. 2015;193:30-35. doi: 10.1016/j.juro.2014.07.102.

4. Van Poppel H, Da Pozzo L, Albrecht W, et al. A prospective, randomised EORTC intergroup phase 3 study comparing the oncologic outcome of elective nephron-sparing surgery and radical nephrectomy for low-stage renal cell carcinoma. Eur Urol. 2011;59:543-552. doi: 10.1016/j.eururo.2010.12.013.

Answer: C

The final pathology from the patient’s partial nephrectomy revealed Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy [SHML]) with negative surgical margins. SHML is a rare histiocytic disorder that involves over-production of non-Langerhans sinus histiocytes, a type of white blood cell. These cells accumulate and can lead to organ damage. This occurs most often in the lymph nodes, but may occur in other areas of the body as well.¹ The reason that these cells over-produce is unknown, although many possibilities have been considered, including viral and bacterial infections and environmental and genetic causes. As this disease is so rare, no large research studies have been performed, and there is no established and widely accepted treatment. However, SHML is usually not life threatening, and many patients do not require treatment.

Per the most recent American Urological Association (AUA) guidelines regarding management of localized kidney cancer, physicians should prioritize partial nephrectomy for the management of the small renal masses (cT1a or less than 4cm) when intervention is indicated.² While the pathology from this case was very unusual, a recent systematic review reported pooled estimates of the proportion of masses with non-malignant histology at partial nephrectomy of 40.4%, 20.9%, 19.6%, and 17.2% for tumors less than 1cm, 1 to less than 2cm, 2 to less than 3, and 3 to less than 4cm, respectively³. While an overall survival benefit has not been demonstrated in randomized trials,⁴ partial nephrectomy minimizes the risk of chronic kidney disease and has equivalent oncologic outcomes to radical nephrectomy. The AUA guidelines also recommend that, in the setting of a solid renal mass, renal mass biopsy is not required for: 

1) young or healthy patients who are unwilling to accept the uncertainties associated with biopsy; or 

2) older or frail patients who will be managed conservatively regardless of the biopsy results.² 

To date, there is no evidence to suggest a survival benefit for adjuvant systemic therapy in patients with clinically localized renal cell carcinoma following surgical resection.