Challenges in Diagnosis of Steatohepatitic Hepatocellular Carcinoma on a Biopsy Specimen

Abstract

Abstract Introduction/Objective Hepatocellular carcinoma (HCC) is the most common primary liver tumor. Steatohepatitic hepatocellular carcinoma (SH-HCC) is a subtype that is associated with metabolic syndrome and alcoholic hepatitis. Diagnosing SH-HCC can be extremely challenging on a biopsy specimen, given that steatohepatitis-like changes can be seen in focal nodular hyperplasia and hepatic adenoma. Herein, we present a very challenging case of SH-HCC that was initially diagnosed as a well-differentiated lesion after multi-institutional consultations. Methods/Case Report A 54-year-old female with past medical history of diabetes and hypertension presented with flank pain and a 2.7 cm liver mass in a background of diffuse hepatic steatosis by CT scan, concerning for malignancy. Viral hepatitis serology workup was negative. Results (if a Case Study enter NA) The liver core biopsy reveals a well-differentiated hepatic lesion with areas of steatosis, fibrosis, and features of steatohepatitic changes including ballooning hepatocytes and Mallory-Denk bodies. No significant cytological atypia is identified. No definitive loss of reticulin is seen by reticulin stain. The cytological or architectural atypia was insufficient in isolation to diagnose HCC. The lesion cells are positive for HepPar-1 and Arginase-1, while negative for Glypican. Diffuse sinusoidal CD34 staining is present. Ki-67 proliferative index is approximately 2%. These changes did not permit a confident diagnosis of hepatic adenoma or hepatocellular carcinoma. The case was sent for consultation by multiple institutions with a consensus diagnosis of well-differentiated hepatic lesion/neoplasm. A follow-up liver wedge resection shows a hepatic neoplasm with areas of loss of reticulin staining. Focal stromal invasion is present. The neoplastic cells are positive for HepPar-1, Arginase-1, glutamine synthetase and Glypican (patchy). Final diagnose was rendered as SH-HCC. Conclusion The diagnosis of SH-HCC requires high level of suspicion on a biopsy specimen, especially in a background of steatohepatitis. A reticulin stain and immunohistochemical stains may not be helpful. Clinical- radiological correlation should always be considered.