Nisha Alle BS, Abstract Co-Author: Nothing to Disclose

Nelly Tan MD, Presenter: Nothing to Disclose

Julie Huss, Abstract Co-Author: Nothing to Disclose

Jiaoti Huang, Abstract Co-Author: Nothing to Disclose

Allan Pantuck MD, Abstract Co-Author: Nothing to Disclose

Steven Satish Raman MD, Abstract Co-Author: Nothing to Disclose

To determine the efficacy, safety and utility of image-guided percutaneous renal mass biopsy (RMB).

With IRB approval, we retrospectively reviewed 173 patients who underwent percutaneous image guided RMB from March 2002 to January 2012. All biopsies were performed using US, CT or CT/US fusion-guided placement of a 17 or 19 introducer needle in the mass and obtainment of core samples with an 18 or 20G core biopsy gun coaxially. Biopsies for medical renal diseases were excluded. Imaging studies, patient demographics, pathology reports and IHC studies were evaluated.

One hundred seventy-three patients underwent RMB for solid renal mass of whom 14/173 (8.1%) were excluded because 1) outside institutional biopsies, 2) incomplete medical records, or 3)  poorly visualized lesions. Three patients had 2 RMBs for bilateral renal cell carcinoma (RCC). Of 159 patients with 162 RMB, 114/162(71.7%) were male with a mean age of 69. Of 162 RMB, 111 were malignant (68.5%), 39 (24.1%) were benign, and 12 (7.4%) were nondiagnostic. IHC was performed in 110 biopsies (67.9%) and was diagnostic in 93%. Twenty-two patients underwent partial nephrectomy; in 21/21 (100%) cases RMB was concordant with nephrectomy for malignancy and in 16/21 (76%) RMB was concordant for RCC subtype. In 2 cases RMB diagnosis of clear cell RCC was changed to papillary type 2. In 1 case, RMB diagnosis of papillary type 1 RCC was changed to unclassified RCC. In 1 case, RMB diagnosis of unclassified RCC was changed to clear cell RCC. In 1 case RMB diagnosis of unclassified RCC was changed to chromophobe. In 1 case of nondiagnostic RMB,  final diagnosis was solitary fibrous tumor on nephrectomy. Sensitivity for detection of malignancy was 100%. Specificity and PPV were 100%. The NPV of benign RMB diagnosis was 100%. There were a total of 12 (7.4%) complications, 11 minor (6.8%) and 1 major (0.6%). Of the minor complications, 7 (4.3%) were postprocedural minor hematomas that resolved conservatively; 1 (0.6%) postprocedural vasovagal reaction; 1 (0.6%) case of hematuria; and 2 (1.2%) cases of small free fluid in the pelvis.

Percutaneous image guided RMB is safe and highly diagnostic when combined with IHC studies and supports a greater role of RMB with imaging to sub-classify renal masses.

The high accuracy of imaging-guided biopsy combined with IHC studies will allow for more targeted management of renal masses.

Alle, N, Tan, N, Huss, J, Huang, J, Pantuck, A, Raman, S, Percutaneous Image-guided Core Biopsy of Solid Renal Masses: Analysis of Safety, Efficacy, Pathologic Interpretation and Clinical Significance  .  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12037432.html