Immunohistochemical and molecular genetic profiling of acquired cystic disease-associated renal cell carcinoma

Aims:  Acquired cystic disease-associated renal cell carcinoma (ACD-associated RCC) is a unique neoplasm that specifically develops in the background of acquired cystic disease of the kidney. The aim was to analyse nine ACD-associated RCCs from three patients to determine their immunohistochemical and molecular characteristics using immunohistochemistry, comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) .
Methods and results:  ACD-associated RCC preferentially expressed proximal nephron phenotype (CD10+/RCC marker+/α-methylacyl-CoA racemase+/glutathione S-transferase-α+/BerEP4+/cytokeratin 7–/E-cadherin–/high-molecular-weight cytokeratin−/MOC31−). CGH combined with FISH demonstrated non-random chromosomal gains clustering on chromosomes 3 (8/9), 7 (6/9), 16 (7/9), 17 (4/9) and Y (5/9). Chromosomal losses were uncommon. The chromosomal aberrations in all multifocal tumours were not identical for the same kidney or for the same patient, indicating a 'field effect' that induces multiple independent clones.
Conclusions:  Although the genetic profiles of ACD-associated RCC showed some similarity to those of papillary RCC, ACD-associated RCC distinctly revealed frequent gains on chromosomes 3 and Y. ACD-associated RCC is characterized not only by its particular clinical setting and histology, but also by its unique immunohistochemical and molecular genetic profiles.