Diagnostic utility of amylase α-1A, MOC 31, and CD 82 in renal oncocytoma versus chromophobe renal cell carcinoma

Indian J Pathol Microbiol. 2020 Jul-Sep;63(3):405-411. doi: 10.4103/IJPM.IJPM_719_19.

Abstract

Objective: Renal oncocytoma (RO) and chromophobe renal cell carcinoma (ChRCC) originate from the same cell origin, that is, the intercalated cells of the collecting duct.[1] In most cases, there are clear morphologic differences between RO and ChRCC; however, in some instances, overlapping features may be encountered and the differentiation between the two entities becomes difficult.[2] Several immunohistochemical markers with different expression patterns in ChRCC and RO have been described to rule out this dilemma.

Materials and methods: About 47 primary renal neoplasms that had been diagnosed as RO or ChRCC were submitted for immunohistochemical staining of amylase α-1A (AMY1A), MOC 31, and CD 82. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy have been analyzed.

Results: AMY1A positivity was observed in all RO cases in our work with 91.7% sensitivity and 100% specificity in the diagnosis of RO. The PPV of its expression was (100%) and NPV (97.2%) with a diagnostic accuracy of 97.9%. A significant high expression of MOC 31 was observed in ChRCC compared to its expression in RO with a statistical significance (P < 0.001). In addition, we obtained 82.9% sensitivity and 91.7% specificity of MOC 31 expression in the diagnosis of ChRCC. The positive predictive value (PPV) was (96.7%), negative predictive value (NPV) (64.7%) with diagnostic accuracy (85.1%). In our studied cases, we detected positive immunoexpression of CD 82 in 10 cases (83.3%) of ChRCC. However, it was lost in all RO cases (100%). CD 82 sensitivity and specificity in differentiating ChRCC from RO were 100% and 83.3%, respectively.

Conclusion: We propose MOC 31 and CD 82 as negative immunostains for RO, as these markers are commonly expressed in ChRCC. In conjunction with AMY1A strong immunopositivity in RO cases, we provide a triple panel of biomarkers (AMY1A, MOC 31, and CD 82) for the distinction between RO and ChRCC.

Keywords: AMY1A; CD 82; MOC 31; chromophobe carcinoma; renal oncocytoma.

Publication types

  • Comparative Study

MeSH terms

  • Adenoma, Oxyphilic / diagnosis*
  • Adenoma, Oxyphilic / genetics
  • Adult
  • Aged
  • Biomarkers, Tumor / genetics
  • Carcinoma, Renal Cell / diagnosis*
  • Carcinoma, Renal Cell / genetics
  • Diagnosis, Differential
  • Female
  • Humans
  • Immunohistochemistry
  • Kangai-1 Protein / genetics*
  • Kidney Neoplasms / diagnosis*
  • Kidney Neoplasms / genetics
  • Male
  • Membrane Glycoproteins / genetics*
  • Middle Aged
  • Predictive Value of Tests
  • Reproducibility of Results
  • Salivary alpha-Amylases / genetics*
  • Sensitivity and Specificity

Substances

  • Biomarkers, Tumor
  • CD82 protein, human
  • Kangai-1 Protein
  • Membrane Glycoproteins
  • AMY1A protein, human
  • Salivary alpha-Amylases

Supplementary concepts

  • Oncocytoma, renal