Patel, Chirag R

Ectopic liver is a rare congenital anomaly characterized by the presence of liver tissue outside the normal liver without any direct connection to it. These lesions are usually detected incidentally during clinical evaluation for other issues. However, they sometimes mimic neoplastic lesions both clinically and radiologically, which poses diagnostic challenges. Here, we present 5 patients with ectopic liver, 4 of which mimicked neoplastic lesions. The first was a 54-year-old woman diagnosed with multiple liver lesions and an enlarged gastro-hepatic lymph node, suspected to be a primary hepatic neoplasm with metastasis. Upon resection, it was found to be a hepatocellular adenoma in the liver and intraabdominal ectopic liver tissue with a small hepatocellular adenoma. Patient 2 was a 36-year-old woman presenting with palpitations and shortness of breath. An echocardiogram revealed a right atrial mass, which was identified as ectopic liver upon microscopic examination. The third patient was a 57-year-old woman with intermittent abdominal pain who underwent cholecystectomy. Microscopy revealed ectopic liver tissue on the gallbladder's serosal surface, along with chronic cholecystitis. The fourth was a 36-year-old woman with a gallbladder polyp, which on microscopy revealed ectopic liver tissue with no other abnormalities in the gallbladder. The fifth patient was a 57-year-old woman presenting with shortness of breath, weakness, and right atrial mass, which was confirmed as ectopic liver. These patients illustrate varied presentations of ectopic liver, sometimes mimicking neoplasia. Hepatocellular adenomas arising in ectopic liver and ectopic liver in intracardiac locations are extremely rare and can be a diagnostic pitfall, as they can clinically, radiologically, and pathologically mimic serious conditions like neoplasia.

Abstract Objectives Nodular regenerative hyperplasia (NRH) is a rare vascular disorder of the liver. Clinically, patients present with portal hypertension with or without a cholestatic pattern of injury. Histologically, the liver parenchyma is composed of small nodules of hypertrophic hepatocytes surrounded by atrophic hepatocytes without significant fibrosis. Nodular regenerative hyperplasia is a difficult diagnosis on biopsy specimens, but biopsy remains the gold standard for diagnosis. In this retrospective review, cytokeratin 7 (CK7) immunohistochemistry (IHC) was used to aid in the diagnosis and further characterization of NRH and NRH-like changes. Methods The H&E-stained slides, reticulin, and CK IHC were reviewed for 22 cases. The percentage of hepatocytes staining for CK7 (0%-100%), the location of staining (centrilobular hepatic progenitor cells vs periportal/bile ductular reaction), and the pattern of staining distribution (patchy or diffuse) were recorded for comparison. Results Of the 22 cases, 9 were CK7 positive. Cases of NRH, however, expressed various degrees of CK7 positivity in centrilobular hepatic progenitor cells, unlike NRH-like changes, which were either CK7 negative or CK7 positive in periportal hepatocytes or in areas of bile ductular reaction. Conclusions In cases with the appropriate clinical history and histology, CK7 immunohistochemistry can be performed to distinguish nodular regenerative hyperplasia (primary) and NRH-like changes (secondary). In difficult cases, CK7 positivity in centrilobular hepatic progenitor cells can help confirm the diagnosis of NRH. These data support NRH as a true entity with a distinct pathophysiology from NRH-like changes.