Tissue microarrays from renal cell tumors: exclusion criteria and rate of exclusion.

Author(s): Hager M, Kolbitsch C, Tiefenthaler W, Haufe H, Kemmerling R, Lucia Moser P

Publication: Scand J Urol Nephrol, 2007, Vol. 41, Page 485-9

PubMed ID: 17853046 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The aims of this study were to determine the frequency of TMA core loss, identify variables that influence core loss, and determine the number of cores required to prevent case loss. In total, 461 cases were analyzed that represented the diagnoses of oncocytoma and clear cell, papillary, sarcomatoid, Bellini type, and Chromophobe renal cell carcinoma (RCC) subtypes. Four TMA cores (0.6 mm diameter) were punched for each case, yielding a total of 1844 TMA cores that were placed into 10 paraffin blocks. Criteria for TMA core exclusion included core loss, less than 25% tumorous tissue within a core, core folding, a core that contained either a hemorrhagic or necrotic area, or the presence of tumor-negative renal tissue.

   Summary of Findings:

   The number of excluded TMA cores based upon the criteria specified above was influenced by section order and tumor type/subtype. The number of excluded cores was nearly three times higher among sections that were cut last (40th TMA section) compared to those cut first (422 versus 158 excluded TMA cores; 9 verse 23%, respectively). The predominant reason for exclusion was core loss, which was responsible for approximately 60% of exclusions. The authors recommend using donor blocks of similar thickness to avoid core loss. The number of excluded cores was also higher in sarcomatoid, papillary, and clear cell RCC subtypes which may be related to the degree of tumor heterogeneity. The authors then extrapolated the frequency of core exclusion to presumed situations in which 1, 2, or 3 cores per tumor were analyzed, and conclude that punching three cores per case would limit the probability of losing all cores for a given case to less than 5% for the first section cut and 15% for the last section cut for oncocytoma and RCC diagnoses, with the exception of sarcomatoid suptypes which had projected losses of 15% and 30%, respectively.

   Biospecimens

   • Tissue - Kidney

   Preservative Types

   • Formalin

   Diagnoses:

   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Morphology	H-and-E microscopy
   Morphology	Macroscopic observation
   Morphology	Tissue microarray

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Aliquots and Components	Aliquot sequential collection	1st section 40th section
   Biospecimen Aliquots and Components	Aliquot size/volume	1 TMA core 2 TMA cores 3 TMA cores 4 TMA cores
   Preaquisition	Diagnosis/ patient condition	Oncocytoma Clear cell renal cell carcinoma Papillary renal cell carcinoma Sarcomatoid renal cell carcinoma Bellini type renal cell carcinoma Chromophobe renal cell carcinoma

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