Radiologicaland Histological Correlation of Ultrasound Guided Fine Needle Aspiration of Focal Liver Lesions

Fine Needle Aspiration (FNA) Has Proven To Be A Very Effective Means Of Obtaining Tissue From Many Different Body Sites For Diagnosis. Fine Needle Aspiration (FNA) Of Liver In Diagnosing Hepatocellular Carcinoma And Liver Metastases Is Proven To Be A Safe, Sensitive And Specific Method When Guided By Ultrasound (US) Or Computed Tomography (CT). Numerous Studies Have Reported A Sensitivity Between 67% And 100% And Accuracy Rate As High As 96%.1 This Diagnostic Method Was First Applied To The Liver As Early As 1895. FNA Is Used Predominantly For Diagnosing Mass Lesions When There Is A Question Of A Neoplastic Process, Either Primary Or Metastatic. The Procedure, However, Has Not Been Successful In Identifying Diffuse Liver Disorders, Such As Hepatitis Or Cirrhosis. The Risk Of Malignancy Growing Along The Biopsy Tract Is Small But Real, With A Reported Incidence Up To 1:1,000 In Abdominal Biopsies. Severe Complications And Mortality Rate Are Low, And Was Reported In 0.04% To 0.05% And 0.004% To 0.008% Respectively In Two Large Reviews Which Included A Combined Total Of More Than 65,000 Abdominal Biopsies.2 In Most Cases, The Diagnosis Presents No Significant Challenges To The Pathologist. Problems Tend To Occur When The Lesion Is A Very Well Differentiated Hepatocellular Process, Which The Pathologist Must Identify As Benign Or Malignant Or A Poorly Differentiated Neoplasm That Arises In A Patient Without Any Other Known Malignancy, For Which The Pathologist Must Determine If It Is A Primary Or Metastatic Lesion. Hepatic Masses Are Increasingly Being Detected On Radiography With The Use Of Sophisticated Abdominal Imaging Studies. Specific Diagnoses Can Often Be Suspected Based On Sensitive Radiographic Imaging Techniques (Computed Tomography, Magnetic Resonance Imaging) Coupled With Clinical Data And Blood Investigations. Except For Hemangiomas, However, Histopathological Diagnosis Remains The Gold Standard In Determining Tumor Classification And Appropriate Clinical Treatment. The Varied Array Of Primary Benign And Malignant Masses And The High Rates Of Metastases To The Liver Account For Much Of The Diagnostic Difficulty Encountered. Primary Tumors Can Be Solid Or Cystic And Can Arise From Epithelium (Hepatocyte, Bile Duct Epithelium, Neuroendocrine Cells) Or Mesenchymal Cells (Principally Endothelium), Or Heterotopic Tissues. The Majority Of Malignant Hepatic Neoplasms In Normal Liver Represent Metastatic Carcinoma Derived From Virtually Any Primary Site, Whereas In Patients With Cirrhosis, Hepatocellular Carcinoma (HCC) Is More Common. Although Diagnosis Of The Primary Hepatic Neoplasms Is Often Straightforward In Resection Specimens, Definitive Classification Of A Biopsy Specimen (Core Or Fine-Needle Aspiration) Showing Evidence Of Benignappearing Hepatocytes Can Be Quite Difficult. The Most Common Problem Encountered In Biopsy Specimens Is In Making The Distinction Between HCC And Metastatic Carcinoma. The Selective Use Of Immunohistochemistry Can Be Quite Useful In This Situation. Since Fine-Needle Aspiration (FNA) Has Assumed A Primary Diagnostic Role In The Evaluation Of Hepatic Masses, This Prospective Study Has Been Done Focussing On The Value Of Percutaneous FNA In The Diagnosis Of Focal Liver Lesions And Their Radiological And Histological Correlation