Peritoneal fine structure of inguinal hernia: a transmission electron microscope study

Area of Science:

• Pathology
• Cell Biology
• Surgical Anatomy

Background:

• The peritoneum's fine structure is crucial for understanding abdominal cavity health.
• Hernias involve defects in abdominal wall integrity, often studied for their structural basis.
• Previous surgical concepts suggested collagen synthesis defects in herniation.

Purpose of the Study:

• To investigate the fine structural changes in the peritoneum of human hernial sacs.
• To compare these changes with normal parietal peritoneum.
• To evaluate the cytological features of mesothelial cells in hernial sacs and their diagnostic implications.

Main Methods:

• Electron microscopy was used to examine the fine structure of normal human parietal peritoneum and hernial sacs.
• Histopathological examination of operative specimens.
• Cytological evaluation of peritoneal effusion.

Main Results:

• Mesothelial cells in hernial sacs retracted, rounded up, and separated, forming intercellular spaces (stomata).
• Significant collagen build-up (fibrosis) was observed in the subserosal tissue of hernial sacs.
• Mesothelial cells exhibited changes mimicking malignant tumors, particularly malignant mesotheliomas, without actual malignancy.
• Peritoneal adhesions, characterized by syncytium-like bonds between mesothelial cells, were observed and documented via electron micrography for the first time.

Conclusions:

• The observed fibrosis in hernial sacs contradicts the concept of collagen synthesis defects as the sole cause of herniation.
• Mesothelial cells in hernial sacs can display significant cytological atypia, mimicking malignancy and necessitating careful pathological evaluation.
• Peritoneal adhesions represent an irreversible process involving mesothelial cell fusion.