title: Unusual reticulin staining pattern in well-differentiated hepatocellular carcinoma.
abstract: BACKGROUND
  Special stains, such as reticulin stain and CD34 immunostain, are very helpful in the diagnosis of well differentiated hepatocellular carcinoma (HCC). Most studies have shown that absent or decreased reticulin stain or an abnormal reticulin pattern with widened trabeculae is reliable for the diagnosis of well-differentiated HCC.
  
  
  METHODS
  We report here two cases of well differentiated HCC with an unusual reticulin staining pattern. A strongly positive reticulin network was preserved within the tumor, which surrounded individual tumor cells in a monolayered trabecular pattern. At the same time, an increased CD34 stain was present in the tumor.
  
  
  CONCLUSIONS
  This unusual reticulin pattern represents part of the diverse reticulin staining patterns seen in HCC. Although this staining pattern is rare, it should be recognized when diagnosing well-differentiated HCC in small samples such as cellblock of fine needle aspiration or small core biopsies.
authors.affiliation: Department of Pathology and Laboratory Medicine, Brody School of Medicine at East Carolina University, 600 Moye Boulevard 7S10, Greenville, North Carolina 27858, USA. iuhong@yahoo.com
authors.forename: Heng
authors.initials: H
authors.lastname: Hong
authors.forename: Bryan
authors.initials: B
authors.lastname: Patonay
authors.forename: James
authors.initials: J
authors.lastname: Finley
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012155:Reticulin / Q000378:metabolism* / Q000648:ultrastructure*
chemical_list: D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D012155:Reticulin