Management of Small Renal Masses

In this episode of BackTable Urology, Dr. Aditya Bagrodia and Dr. Phil Pierorazio discuss the management of small renal masses.

Most small renal masses found incidentally through imaging from another cancer workup or an injury, and most small renal masses are not cancer. It is important to take into account the patient’s family and social history, especially if there is a family history of renal cell carcinoma and renal disorders. Dr. Pierorazio looks specifically for flank pain, hematuria, and a history of smoking because these are all risk factors for cancerous small renal masses. In every patient, he orders a basic metabolic panel and a urodynamic analysis in order to observe renal function. Because CT scans are easily reproducible and interpreted, it is his first choice imaging modality. He also orders a chest x-ray, as pulmonary metastasis is common in renal cancer.

Active surveillance is a reasonable option once a small renal mass under 3 centimeters is discovered. Before deciding to put a patient on active surveillance as opposed to surgical intervention, Dr. Pierorazio assesses patient age, life expectancy and related comorbidities, and tumor size. However, tumors smaller than 3 centimeters should be removed if there is a possibility that the masses are caused by hereditary, aggressive cancers. High suspicion for these cancers should be raised in young women with a history of hysterectomies for fibroids. Another distinction that must be made is the difference between benign cysts and solid masses. Renal tumors are often not always completely solid, so they may masquerade as cysts. In order to improve the accuracy of the diagnosis, it is important to confirm the mass characteristics with multiple modalities.

A biopsy may be needed if the renal mass grows above 3 centimeters or if the patient is wanting more information. Additionally, a biopsy can help a surgeon decide whether a partial or radical nephrectomy is a better option. There are many different surgical options following the kidney biopsy: enucleation, nephrectomy, and ablation are three of the most common options. Surgical treatments can be sorted into two different types: partial nephrectomy and nephron-sparing options that maximize preservation of renal parenchyma. If a tumor is larger than 3 centimeters and well-encapsulated, Dr. Pierorazio favors enucleation. On the other hand, surgery may be contraindicated in older patients with multiple comorbidities because they are unlikely to progress to end-stage renal disease. For this reason, Dr. Pierorazio emphasizes the importance of listening to patients’ fears and desires, as both nephrectomy and dialysis can result in different risks and complications.