Electron microscopic observations and X-ray microanalysis of a multinucleated giant cell

Area of Science:

• Pathology
• Cell Biology
• Materials Science

Background:

• Giant cells and macrophages are crucial for bodily defense and repair.
• Inflammatory processes can involve these cells in various tissues.
• Haemosiderin, an iron storage complex, forms from hemoglobin breakdown.

Purpose of the Study:

• To investigate the cellular composition and elemental content of an inflammatory mass in the temporal bone.
• To identify the source of high iron concentrations within giant cells and macrophages in this specific context.
• To assess the applicability of electron probe microanalysis on chemically fixed biological specimens.

Main Methods:

• Histological examination of an inflammatory mass from the temporal bone.
• Ultrastructural analysis of giant cells and macrophages.
• X-ray microanalysis (electron probe microanalysis) to determine elemental composition.

Main Results:

• Giant cells and macrophages were identified within the inflammatory mass.
• A very high iron content was detected in electron-dense precipitates within these cells.
• Evidence of hemorrhage was observed in the tissue sections, suggesting the source of iron.

Conclusions:

• The high iron content in temporal bone inflammatory cells is likely due to phagocytosis of haemosiderin, resulting from hemorrhage.
• Electron probe microanalysis is a valuable technique for analyzing elemental composition in chemically fixed tissues, including archived samples.
• This study underscores the role of iron metabolism in inflammatory responses within the temporal bone.