Virtual Karyotype of Renal Carcinoid Tumors by SNP Microarrays
Robert W Allan, Jennifer A Jeung, Dengfeng Cao, Anil V Parwani, Luan D Truong, Federico A Monzon. University of Florida College of Medicine, Gainesville, FL; Washington University School of Medicine, St. Louis, MO; University of Pittsburgh School of Medicine, Pittsburgh, PA; The Methodist Hospital Research Institute, Weill Cornell Medical College of Cornell University, Houston, TX
Background: Renal carcinoid tumors (RCT) are rare neoplasms. Unlike carcinoid tumors at other anatomic site, scarce data are available on the genetic changes in RCT. We sought to determine if there were characteristic chromosomal copy number changes in RCT using SNP arrays on archival formalin-fixed paraffin embedded (FFPE) tissue blocks.
Design: We obtained demographic, clinicopathologic information and archival FFPE tissue blocks from 5 patients with RCT from multiple institutions. DNA from the FFPE tissue blocks was analyzed with 250K Nsp SNP microarrays (Affymetrix, Santa Clara, CA). Virtual karyotypes were obtained detailing the genomic imbalances and loss of heterozygosity (LOH).
Results: The average age was 56 years (Male:Female 2:3). Tumors invaded perinephric adipose tissue (n= 5), lymph nodes (n=3) or presented with metastatic disease (n=2, both liver). Three renal carcinoid tumors showed no chromosomal abnormalities (NCA). One tumor showed focal deletions in 3q [-3q(q21.31-q26.32]. One tumor, an atypical carcinoid, showed multiple chromosomal abnormalities including loss of 3p and other chromosomal losses [-1(p31.1-p31.1), -1(p22.3-p11.2), -3(p26.3-q11.2), -10(q21.2-q26.3), -10(q21.1-q21.1), -11(q14.3-q23.3), -13, -16(q13-q24.3)].
Conclusions: Most renal carcinoid tumors showed no chromosomal abnormalities by SNP microarrays (3/5 tumors). Chromosomal abnormalities of chromosome 3 (3q or 3q loss) were present in the 2/5 tumors and one tumor (atypical carcinoid) showed complex abnormalities (loss 3p, additional chromosome loses). Loss of 3p is of interest as this is characteristic of clear cell (conventional) renal cell carcinoma. VHL mutation analysis in this tumor is underway. With the exception of more complex chromosomal changes being present in an atypical carcinoid, in the remaining tumors there was no difference between NCA tumors and those with no chromosomal abnormalities. A larger study of these rare tumors may identify recurrent abnormalities that may associated with clinical behavior.
Category: Genitourinary (including renal tumors)
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 85, Wednesday Morning