Frozen Diagnostic Features and Pitfalls of Needle Core Biopsies for Hepatocellular Mass Lesions
Nupam Patel, Ravi Patel, Jiang Wang. University of Cincinnati, Cincinnati, OH
Background: Frozen evaluation of liver masses provides fast diagnosis for patients and allows surgeons to manage the lesions immediately. Frozen diagnosis is quick, convenient and valuable for clinicians and patients; however, may be challenging for pathologists, especially on needle core biopsies. At our institute, frozen diagnosis on needle core biopsies has been a daily practice for several years. We reviewed cases in recent years and summarized the features and pitfalls of diagnosis.
Design: Needle core biopsies from 196 patients with hepatocellular mass lesions, including 157 hepatocellular carcinoma(HCC), 26 focal nodular hyperplasia(FNH) and 13 hepatic adenoma(HA), were identified from the archives in University Hospital at University of Cincinnati between 2007 and 2011. All frozen sections and corresponding paraffin sections were reviewed and evaluated. In addition, the background liver and the quality of frozen section were assessed.
Results: Diagnosis of moderately or poorly differentiated HCC is usually easy to make. FNH may be mistakenly called “normal”. Frozen diagnosis of HA and well-differentiated HCC in non-cirrhotic liver remains the most challenging. Absence of portal tracts, unpaired vessels and pseudoglandular formation may be seen on both HA and HCC. Presence of a trabecular pattern, cells with higher N/C ratio along with the presence of fibrotic bands are more indicative of HCC while fatty changes are more commonly seen in HA. Young females, a history of taking OCP, lack of fibrotic bands(direct transition from tumor to normal tissue), and similar cytology(if no steatosis present) to normal liver contribute to a diagnosis of HA. A well-differentiated hepatocellular neoplasm in a background of cirrhosis is almost always HCC. Hepatocytes surrounded by or adjacent to a fibrotic band lacking inflammation and ductules are important clues favoring HCC as compared to a cirrhotic nodule.
Conclusions: Accurate frozen diagnosis can be made for majority of cases using the features and suggestions mentioned above. Among the lesions evaluated, HA has the highest discordance. “Well-differentiated hepatocellular neoplasm” is suggested to be used in non-cirrhotic livers if a definitive diagnosis cannot be made. In addition, there is great utility when we request lesional tissue and normal tissue in order to compare morphology. Deeper levels are useful when the lesional fragments are small, at the edge and/or poor section quality. Additional cores are required if original biopsy is inadequate for a definitive diagnosis. Consulting an experienced liver pathologist is recommended whenever needed.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 111, Wednesday Morning