Hepatic oncocytes. Incidence, staining characteristics, and ultrastructural features

Area of Science:

• Hepatology
• Cell Biology
• Pathology

Background:

• Ground-glass hepatocytes, often containing hepatitis B surface antigen, exhibit specific cytoplasmic changes.
• Similar-appearing cells lacking orcein positivity were observed in a significant percentage of cirrhosis cases.

Purpose of the Study:

• To characterize novel hepatocytes with distinct morphological and staining properties observed in cirrhosis.
• To differentiate these newly identified cells from previously described ground-glass hepatocytes.

Main Methods:

• Light microscopy with specific stains (orcein, phosphotungstic acid-hematoxylin).
• Electron microscopy to analyze cytoplasmic ultrastructure.
• Analysis of 49 cases of cirrhosis, noting cell prevalence and clinical associations.

Main Results:

• Hepatocytes with granular, eosinophilic cytoplasm, distinct from orcein-positive ground-glass hepatocytes, were identified.
• These cells, termed hepatic oncocytes, showed abundant, densely packed mitochondria via electron microscopy.
• Hepatic oncocytes were found in 26.5% of cirrhosis cases, predominantly in established disease, irrespective of etiology.
• These cells did not exhibit signs of regeneration, though they could form nodular aggregates.

Conclusions:

• Hepatic oncocytes represent a distinct cell type in cirrhosis, differentiated from ground-glass hepatocytes by specific histochemical and ultrastructural features.
• The presence of hepatic oncocytes is associated with established cirrhosis, but their exact role and pathogenesis require further investigation.
• Distinguishing hepatic oncocytes from ground-glass hepatocytes may necessitate specialized histochemical staining techniques.