From the Guidelines
Corpora amylacea, also known as amyloid bodies, are small, round, glycoprotein structures that accumulate in various organs, including the brain, and are associated with aging and certain neurodegenerative diseases. These microscopic bodies are typically 10-50 micrometers in diameter and appear as basophilic structures that stain positively with periodic acid-Schiff (PAS) due to their high polysaccharide content. Some key characteristics of corpora amylacea include:
- They are most commonly found in the periventricular and subpial regions of the brain, particularly in astrocytic processes near blood vessels
- They may serve protective functions by sequestering potentially harmful substances and participating in the clearance of cellular waste
- They accumulate significantly in neurodegenerative conditions like Alzheimer's disease and multiple sclerosis, though they are not specific diagnostic markers for these conditions
- Their presence is generally considered a normal aging phenomenon rather than pathological, representing the brain's attempt to isolate and remove metabolic byproducts Although the provided study 1 focuses on AL amyloidosis, it does not directly address corpora amylacea, but it does discuss the broader topic of amyloidosis, which is relevant to understanding the nature of these structures. Some other key points to consider about corpora amylacea include:
- Similar structures can also be found in the prostate, lungs, and other tissues, though their composition may vary slightly depending on location
- The exact function and clinical significance of corpora amylacea are still not fully understood and require further research.
From the Research
Definition and Composition of Corpora Amylacea
- Corpora amylacea (CA) are glycoprotein-based depositions that accumulate in the normal aging brain or consecutively to different neuro-degenerative diseases 2.
- They are composed of amyloid-like fibrils and have a strong positivity for the PAS reaction and anti-lysozyme antibodies 3.
- CA are also found in other organs, including the prostate, lung, and uterus, and are associated with ageing and several pathological conditions 4, 5, 6.
Morphology and Structure
- CA have a round, basophilic morphology based on bi-dimensional observations, but three-dimensional analysis reveals a more complex, branched structure 2.
- They can form highly branched three-dimensional lattices and can be found in association with astrocytes and blood vessels 2.
- CA can also be found in the alveolar space, surrounded by exudate alveolar macrophages or multinuclear giant cells 3.
Formation and Function
- The formation of CA is not fully understood, but it is thought to involve the sequential aggregation, fusion, coalescence, and compaction of degenerated cells or cellular components 3, 6.
- CA may serve as waste containers, sequestering waste products and foreign substances, and assembling them within a glycan structure 6.
- They can be intracellular or extracellular structures and can be phagocytosed by macrophages 6.
Associations with Disease and Lifestyle Factors
- CA are associated with chronic inflammation, particularly in the prostate, and may be more common in men with higher body mass index 5.
- They are also associated with certain molecular and histological factors, such as the presence of amyloid proteins and the absence of certain genetic mutations 4, 5.
- CA may be less common in certain types of prostate cancer, such as those with high Gleason grade or the presence of the TMPRSS2:ERG fusion 5.