Lessons learned from the comparative study between renal mass biopsy and the analysis of the surgical specimen.
BACKGROUND
The role of renal mass (RM) biopsy is currently under discussion. As a result of the progressive increase in the incidental diagnosis of RMs (which have a higher percentage of benignity and well-differentiated cancers), new approaches have emerged such as observation, especially with elderly patients or those with significant comorbidity. RM biopsy (RMB) should provide sufficient information for making this decision, but so far this has not been the case. We examine our prospective series of in-bench RMBs after surgery and compare them with the anatomy of the removed specimen.


METHODS
We obtained (prospectively, in-bench and with a 16-gauge needle) 4 biopsies of RMs operated on in our department from October 2008 to December 2009. These RMs were analyzed by 2 uropathologists and compared with the results of the specimen.


RESULTS
We analyzed 188 biopsies (47 RMs); 12.75% were "not valid". The ability of biopsy to diagnose malignancy or benignity was 100%, and the coincidence in the histological type was 95%. The success in determining the tumor grade was 100% when the cancer was low-grade and 62% when high-grade. None of the analyzed data (necrosis, size, etc.) influenced the results in a statistically significant manner.


CONCLUSIONS
RMB with a 16-G needle enables the differentiation between malignancy and benignity in 100% of cases, with a very similar diagnostic accuracy in the tumor type. Tumor grade is still the pending issue with renal mass biopsy.
Servicio de Urología, Hospital Universitario Marqués de Valdecilla, Santander, España. Electronic address: mariodominguezesteban@gmail.com.
M
M
Domínguez-Esteban
Unidad de Uro-Oncología, Servicio de Urología, Hospital Universitario 12 de Octubre, Madrid, España.
F
F
Villacampa-Aubá
Sección de Uro-Patología, Servicio de Anatomía Patológica, Hospital Universitario 12 de Octubre, Madrid, España.
H
H
Garcia-Muñóz
Unidad de Uro-Oncología, Servicio de Urología, Hospital Universitario 12 de Octubre, Madrid, España.
A
A
Tejido Sánchez
Unidad de Uro-Oncología, Servicio de Urología, Hospital Universitario 12 de Octubre, Madrid, España.
J
J
Romero Otero
Unidad de Uro-Oncología, Servicio de Urología, Hospital Universitario 12 de Octubre, Madrid, España.
F
F
de la Rosa Kehrmann
D001707:Biopsy, Needle; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery*; D009392:Nephrectomy; D009929:Organ Size; D011446:Prospective Studies
Biopsia; Biopsy; Grade; Grado; Histology; Histología; Masa renal; Renal mass