SAN FRANCISCO, CA USA (UroToday.com) - Dr. William Mayo-Smith was part of a very distinguished panel, discussing the clinical and genetic heterogeneity in renal cell carcinoma and the evolving indications for renal biopsy.
He began by stating that historically, biopsy of renal mass has played a less prominent role because patients with solid renal masses never presented until they were symptomatic, and total nephrectomy was the gold standard and the only recommended option then. However, because of a number of several newer treatment options, establishing a definitive diagnosis is critical to choosing the most appropriate therapy for the given patient. Due to increased use of cross-sectional imaging, close to 70% of the new masses are being diagnosed incidentally, and it’s important to know that not all solid masses detected on cross-sectional imaging are renal cell carcinomas. A solid renal mass can be an oncocytoma, angiomyolipoma, lymphoma, infection, or metastasis; and using only diagnostic imaging it’s not always clear to distinguish them from cancer. Furthermore, he went on to explain that with the advancements in less invasive treatment options (robotic, laparoscopic, cryoablation, or radiofrequency ablation), particularly in patients with renal compromise, it is critical to establish a definitive diagnosis for appropriate treatment.
Several well-performed studies have shown that a substantial percentage of small renal masses (less than 4 cm) are benign. Dr. Mayo-Smith presented a data from Mayo clinic, published several years back, on 2 770 nephrectomy specimens. In this paper, Frank, et al. correlated the tumor type and histologic grade as a function of renal mass size. They reported that 25% and 50% of renal masses less than 3 cm and 1 cm were benign, respectively. They concluded that tumor type and grade were directly related to tumor size. In regard to the role of renal biopsy, the American Urological Association now suggests biopsy of stage I (< 7 cm) renal masses should be performed if it will assist in clinical decision making and patient counseling. He further went on talking about advancements in image-guided renal biopsy techniques. The diagnostic yield of biopsies is now between 80 to 100%, with an acceptably low complication rate of less than 5%. It is also important to know that the false-negative biopsy rate is only 1%. He then mentioned that while the concern for needle-track seeding has been historically cited, this is an increasingly rare event.
Next he talked about the prominent advances in pathology, cytology, and immunohistochemistry to a point that now, with a single core biopsy, pathologists can usually report on the tumor grade and subtype. Using markers (CD10 and iron stains), smooth-muscle cell antibodies, and renal cell carcinoma antibodies, renal tumors can now be more reliably diagnosed and subtyped. He concluded his presentation by saying that with recent advancements in imaging, biopsy techniques, surgical technology, and cystopathologic techniques, the biopsy of solid renal masses should be strongly considered in most of the patients presenting with a solid renal mass.
Highlights of a presentation by William W. Mayo-Smith, MD, FACR at the 2014 Genitourinary Cancers Symposium - January 30 - February 1, 2014 - San Francisco Marriott Marquis - San Francisco, California USA
Rhode Island Hospital, Providence, RI USA