title: Primary bladder adenocarcinoma versus metastatic colorectal adenocarcinoma: a persisting diagnostic challenge.
abstract: OBJECTIVE
  This study attempted to distinguish primary bladder adenocarcinoma (PBA) from metastatic colonic adenocarcinomas (MCA), which is a difficult diagnostic and clinical problem.
  
  
  METHODS
  Twenty-four cases of bladder adenocarcinomas (12 primary & 12 metastatic colorectal) were included in the study with urothelial carcinoma (UC) and colonic adenocarcinoma (CA) as controls. A panel of immunohistochemical (IHC) stains along with fluorescence in-situ hybridization (FISH), using the UroVysion probe set, was performed.
  
  
  RESULTS
  The majority of the PBAs presented with advanced disease. Enteric histologic subtype was the most common morphological variant. Strong nuclear with cytoplasmic-membranous staining of β-catenin was seen in 75% of MCA and only 16.7% PBA (<10% staining cells). Although abnormal nuclear staining with E-cadherin was seen in both PBA and MCA, it was more frequent in former. CK-7, CK-20, villin and CDX-2 stains were not helpful in distinguishing the two entities. FISH did not reveal any unique differences in chromosomal abnormality between the two groups.
  
  
  CONCLUSIONS
  Although there was a statistically significant difference in β-catenin and E-cadherin staining between two groups, we did not find any IHC or FISH marker that was specific for PBA. Distinction between PBA and MCA remains a diagnostic problem and clinical correlation is vital before rendering a diagnosis.
  The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1393156268152357.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA 15232, USA.
authors.forename: Somak
authors.initials: S
authors.lastname: Roy
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Smith
authors.forename: Kathy M
authors.initials: KM
authors.lastname: Cieply
authors.forename: Marie B
authors.initials: MB
authors.lastname: Acquafondata
authors.forename: Anil V
authors.initials: AV
authors.lastname: Parwani
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000556:secondary; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D000071616:CDX2 Transcription Factor; D015820:Cadherins / Q000032:analysis; D002869:Chromosome Aberrations; D002877:Chromosomes, Human; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D018398:Homeodomain Proteins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D053554:Keratin-20 / Q000032:analysis; D053552:Keratin-7 / Q000032:analysis; D008297:Male; D008840:Microfilament Proteins / Q000032:analysis; D008875:Middle Aged; D011237:Predictive Value of Tests; D001749:Urinary Bladder Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000556:secondary; D051176:beta Catenin / Q000032:analysis
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C513384:CDH1 protein, human; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D018398:Homeodomain Proteins; C507499:KRT20 protein, human; C507497:KRT7 protein, human; D053554:Keratin-20; D053552:Keratin-7; D008840:Microfilament Proteins; D051176:beta Catenin; C026615:villin