title: [Progress in the pathologic study of small renal masses. Can diagnostic accuracy be improved?].
abstract: OBJECTIVE
  Early diagnosis of renal masses has resulted in most of them being smaller than in the past, so that up to 61% of masses diagnosed are ≤ 4 cm. Due to this fact the term small renal mass (SRM) has been forged, and there is a search to determine their biology. The objective of this article is to detail the possible help of pathology in this task.
  
  
  METHODS
  We performed a PubMed review of the bibliography from January 2000 to march 2012.
  
  
  RESULTS
  Preoperative CT scan evaluation of the size of the renal masses correlates well with specimen measures(It only exceeds 3.1 mm). Size and growing speed do not allow recognizing benign masses, although it is true that the smaller the mass and the slower the growing speed the less aggressive the biology. Biopsy of the mass is the best method to determine the biology; it usually obtains valid material in 80.6% of the cases, and among them histologic subtype is determined in 88% to 93% of the cases and grade from 63.5% to 68%, with good reproducibility between observers (kappa from 0.010 to 0.830). This diagnostic capacity may increase joining biopsy and FNAC (reaching up to 96.5%) or determining some immunohistochemical markers (increase from 9% to 18%) or using some FISH (7% increase) or molecular methods (11.7% increase).
  
  
  CONCLUSIONS
  The biopsy of SRMs is useful and may answer the new demands to determine their nature and help therapeutic indications both surgical and with new drugs.
authors: Sección de Patología, Fundació Puigvert, Universidad Autónoma de Barcelona, Barcelona, España. falgaba@fundacio-puigvert.es
authors: Ferran
authors: F
authors: Algaba
mesh_terms: D001706:Biopsy; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery / Q000628:therapy; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed