Hepatic neoformations

Area of Science:

• Histopathology
• Oncology
• Gastroenterology

Background:

• Accurate histologic description of liver lesions is crucial for diagnosis and treatment.
• Distinguishing between neoplasia, malformation, regeneration, and hyperplasia can be challenging.
• A unified terminology for liver lesions characterized by cellular multiplication is needed.

Purpose of the Study:

• To provide an accurate histologic description and illustration of liver lesions.
• To introduce a master term 'neoformation' for lesions with cellular multiplication.
• To classify liver neoformations into mesenchymal and epithelial categories.

Main Methods:

• Histologic examination and illustration of liver lesions.
• Classification based on phenomenological criteria, distinguishing mesenchymal and epithelial types.
• Subgroup definitions adhering to current nomenclatory usage, with novel terms for endothelial tumors.

Main Results:

• Introduction of the term 'neoformation' to encompass lesions with cellular multiplication.
• Distinction between mesenchymal (angiomatous and non-angiomatous) and epithelial neoformations.
• Further classification of epithelial neoformations into hepatocellular and cholangiocellular types.

Conclusions:

• The proposed classification provides a systematic approach to liver neoformations.
• The term 'neoformation' aids in unifying the description of diverse liver lesions.
• Phenomenological differentiation, while not identical to histogenesis, is practical for classification.