Year : 2021 | Volume
: 64 | Issue : 5 | Page : 4--5
Evolving significance of liver pathology
Department of Pathology, GB Pant Institute of Postgraduate Medical Education and Research, New Delhi, India
Department of Pathology, GB Pant Institute of Postgraduate Medical Education and Research, New Delhi
|How to cite this article:|
Sakhuja P. Evolving significance of liver pathology.Indian J Pathol Microbiol 2021;64:4-5
|How to cite this URL:|
Sakhuja P. Evolving significance of liver pathology. Indian J Pathol Microbiol [serial online] 2021 [cited 2021 Sep 22 ];64:4-5
Available from: https://www.ijpmonline.org/text.asp?2021/64/5/4/317911
Liver pathology has two main elements: nonneoplastic and neoplastic. These elements also remain linked as primary liver tumors are often a consequence of a preexisting liver disease. Role of liver biopsy in the current era of newer imaging modalities has undergone a sea change in the last few decades. Initially, a large number of biopsies were from patients with viral hepatitis, for grading of activity and staging of fibrosis. This was overtaken by biopsies for confirming the diagnosis of Nonalcoholic Steatohepatitis (NASH) and its grading and staging. While liver biopsy for NASH is still common in several centers, biopsies for viral hepatitis are done occasionally as the viral load along with the liver enzymes are more useful to guide therapy. Often the role of the pathologist is to confirm a clinical diagnosis especially where the clinical data are conflicting, or to detect any unsuspected disease or comorbidity. In addition, the liver biopsy helps guide treatment decisions based on the predominant histological features.
The role of liver biopsy in the diagnosis of metabolic and cholestatic disorders in pediatric patients as well as adults must be emphasized as genetic advancements and newer immunohistochemistry (IHC) markers are offering new perspectives and therapeutic avenues to such patients. Liver biopsy continues to play an important role in the diagnosis, prognosis, and management of patients with genetic disorders like hemochromatosis, Wilson's disease, progressive familial intrahepatic cholestasis (PFIC), and storage disorders.
The end result of chronic liver disease is fibrosis of varying stages finally culminating in cirrhosis. Thus, the role of the pathologist is not only to quantify the degree of fibrosis, but also to assess the regression of fibrosis, the thickness of fibrous septa, and architectural changes which can predict response to antifibrotic therapies and thus prognosis. Several grading and staging systems have been proposed for both viral hepatitis and NASH.,, Liver biopsy versus noninvasive methods of assessing fibrosis in the liver has been a subject of many a debate. However, newer techniques such as second-harmonic generation and two-photon microscopy have provided greater reliability for fibrosis and steatosis assessment.,
Diagnosis of liver space-occupying lesion (SOL) is another area where the Pathologist plays a key role, especially in situations wherein the radiology is not conclusive. In such situations, a biopsy may be required to differentiate between hepatocellular carcinoma (HCC) and an adenoma or focal nodular hyperplasia in a noncirrhotic liver, or from a dysplastic nodule in a cirrhotic liver. IHC and molecular studies have improved our insight into the pathogenesis and categorization of prognostically distinct subtypes of hepatic adenomas. This helps identify those with a higher risk for progression to malignancy. With the advent of surrogate IHC markers, the pathologist must be able to diagnose and subclassify the phenotypic and molecular subtype of HCC as this may impact treatment and prognosis. IHC plays a key role not only in diagnosis but also in subtyping for the purpose of molecular classification and prognostication. In the latter, role antibodies such as p53 and beta-catenin, etc., are useful. With the era of predictive and precision medicine, and the role of targeted therapy, such information provided by the pathologist is vital.
Improvement in surgical techniques have increased the number of liver resections and liver transplants for varying etiologies. It is important for the pathologist to appropriately gross the liver resection specimen in order to provide the pertinent information required. Furthermore, post-transplant liver biopsies are often done in graft dysfunction to assess the type of rejection and to distinguish it from drug-induced liver injury, acute hepatitis due to opportunistic viral infections, de novo disease or recurrence of the primary disease. Liver biopsy has also been useful in guiding the diagnostic criteria for antibody-mediated rejection in the liver.
To conclude, the indications for liver biopsy and the role of the pathologist in liver biopsy interpretation has seen a lot of changes in the past few decades. Currently, the role is (a) to confirm a clinical diagnosis such as NASH, Autoimmune liver disease and look for any co-morbidity, (b) estimation of liver fibrosis, (c) diagnosis and categorization of liver SOL, (d) phenotypic and molecular classification of HCC, (e) assessment of post-transplant biopsies, etc., to name a few. Liver Pathology continues to improve patient care by guiding diagnosis and therapy and is an important complementary tool in clinical research trials.
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