Renal mass biopsy has experienced a rapid increase in popularity over the last several years. Traditionally, percutaneous biopsy has been associated with low diagnostic yield, with rates of non-diagnostic samples as high as 31% (1).
However, technological advances and improvements in technique have led to increased use of biopsy for diagnosis and workup of renal mass. As this technology becomes more widespread, it is important for urologists to be aware of potential pitfalls of the post-biopsy patient.
We present a 61 year-old female with a history of ovarian cancer who underwent a biopsy of an incidentally discovered renal mass. After the diagnosis of renal cell carcinoma was made, she went on to undergo a robotic partial nephrectomy. At the time of surgery, a hematoma was discovered posterior to the mass and accidentally violated (Figure). The hematoma contents were grossly suspicious for cancerous tissue, and a wide resection margin was taken. Post-operatively the patient suffered from local recurrence and omental metastases. Completion nephrectomy and omentectomy were performed.
Our experience represents an important potential situation to be aware of when performing partial nephrectomy after renal mass biopsy. Imaging is not typically repeated in the period between biopsy and partial nephrectomy, so the surgeon may be unaware of any hematoma at the time of surgery. Although intraoperative ultrasound may be useful for this purpose, the posterior approach of most renal mass biopsies means that the hematoma may be difficult to visualize (as it was in this case).
Renal mass biopsy has traditionally been reserved for suspected lymphoma, abscess or metastatic disease. However, recent advances in techniques have led to more widespread use. One recent series reported a 4% non-diagnostic rate and a positive predictive value of 100% (2). Complications are generally rare, but have been reported. Hematoma is the most common, occurring in 0-6.4% of cases (3). A much more rare complication is seeding of the biopsy tract, which is only reported a handful of times in the literature (4).
In our case, it is likely that the biopsy caused a hematoma which was subsequently seeded by the tumor tract. In the modern era of increasing prevalence of mass biopsy, high volume renal surgeons should expect to encounter this issue and be prepared to manage it intraoperatively. We recommend a very thorough assessment with intraoperative ultrasound, followed by a wide excision of any suspicious areas. While this complication is the first of its kind to be reported, it is an important pitfall for any renal surgeon to be aware of.
Figure. Intraoperative picture of the partial nephrectomy, demonstrating the tumor (T), hematoma (H), and kidney (K).
References:
1. Dechet CB, Zincke H, Sebo TJ, King BF, LeRoy AJ, Farrow GM, et al. Prospective analysis of computerized tomography and needle biopsy with permanent sectioning to determine the nature of solid renal masses in adults. The Journal of urology. 2003;169(1):71-4.
2. Maturen KE, Nghiem HV, Caoili EM, Higgins EG, Wolf JS, Jr., Wood DP, Jr. Renal mass core biopsy: accuracy and impact on clinical management. AJR American journal of roentgenology. 2007;188(2):563-70.
3. Leveridge MJ, Finelli A, Kachura JR, Evans A, Chung H, Shiff DA, et al. Outcomes of small renal mass needle core biopsy, nondiagnostic percutaneous biopsy, and the role of repeat biopsy. European urology. 2011;60(3):578-84.
4. Volpe A, Kachura JR, Geddie WR, Evans AJ, Gharajeh A, Saravanan A, et al. Techniques, safety and accuracy of sampling of renal tumors by fine needle aspiration and core biopsy. The Journal of urology. 2007;178(2):379-86.
Written by:
Andrew C Harbin, MD
Daniel D Eun, MD
Department of Urology, Temple University School of Medicine, Philadelphia, PA.