THE USEFULNESS OF THE RETICULIN STAIN IN THE DIFFERENTIAL-DIAGNOSIS OF LIVER NODULES ON FINE-NEEDLE ASPIRATION BIOPSY CELL BLOCK PREPARATIONS

We reviewed fine-needle aspiration biopsy (FNAB) cell blocks of hepato cellular carcinoma (I-ICC) (n = 16) and benign hepatic processes (n = 16) to evaluate the significance of reticulin staining (Gomori stain) in combination with standard cytomorphologic and architectural criteri a, We analyzed tile staining pattern using semiquantitative grading: n ormal, variable, decreased, or virtually absent, Also, we graded the c ell thickness of the hepatic trabeculae as greater than or less than t hree cells, Fourteen of 16 biopsy specimens of benign processes demons trated a normal reticulin framework, with staining outlining hepatic t rabeculae less than three cell layers in thickness, Staining was marke dly decreased in one case of steatosis and virtually absent in one cas e of cirrhosis. In contrast, all of the 16 HCCs demonstrated either a virtually absent (7 of 16), decreased (6 of 16), or variable (3 of 16) reticulin staining pattern, with thickened trabeculae greater than th ree cell layers, We conclude that the reticulin stain is a useful adju nct in the differential diagnosis of liver nodules on FNAB cell block preparations and that it is particularly useful in distinguishing HCC ii om benign hepatic processes, Virtually absent or decreased reticuli n staining and staining outlining trabeculae greater-than three cells in thickness support the diagnosis of HCG. Normal reticulin staining o utlining well-defined hepatic trabeculae less than three cell layers i n thickness supports the diagnosis of a benign hepatic process.