Intranuclear inclusions

Intranuclear inclusions are abnormal collections of protein or other material found within the nucleus of a cell. These inclusions appear as rounded, compact masses that are often distinct from the surrounding nuclear material because of their colour, density, or composition.

Medical conditions associated with intranuclear inclusions

Intranuclear inclusions are associated with various medical conditions, the most common being viral infections. Some of the notable conditions include:

• Herpesvirus infections: Conditions such as herpes simplex virus (HSV) and varicella-zoster virus (VZV) commonly produce intranuclear inclusions known as Cowdry Type A inclusions.
• Cytomegalovirus (CMV) infection: CMV can cause inclusions in the nuclei of infected cells, which are often observed in immunocompromised patients, such as those with HIV/AIDS or transplant recipients.
• Adenovirus infections: Adenovirus infection can lead to the formation of intranuclear inclusions in the respiratory or gastrointestinal tract cells.
• Measles: Subacute sclerosing panencephalitis (SSPE), a rare chronic form of CNS disease caused by the measles virus which shows intranuclear inclusions in brain cells.
• Neurodegenerative conditions: Huntington’s disease and some forms of frontotemporal dementia are associated with the presence of intranuclear inclusions, which are thought to result from abnormal protein accumulation.
• Liver conditions: Conditions like Wilson’s disease and certain drug-induced hepatotoxicities can show intranuclear inclusions due to the accumulation of abnormal proteins or other cellular byproducts in liver cells.

What are intranuclear inclusions made of?

In cases of infection, intranuclear inclusions are composed of viral particles or altered cellular material from the virus’s replication process. The content can vary depending on the type of disease, but viral inclusions often contain nucleic acids and proteins. In non-infectious diseases, inclusions are composed of abnormal protein aggregates.

What is the significance of finding intranuclear inclusions in a tissue sample?

Finding intranuclear inclusions in a tissue sample is significant for several reasons:

• Diagnosis: The presence of these inclusions is crucial for diagnosing specific viral diseases and some neurodegenerative or liver conditions, based on their appearance and the affected cell types.
• Treatment implications: Detecting these inclusions in viral infections can guide the use of antiviral treatments. In neurodegenerative or liver diseases, it can impact the management and therapeutic approaches.
• Prognosis: The presence and extent of inclusions can provide insights into the severity and progression of the disease, especially in vulnerable patients.

About this article

Doctors wrote this article to help you read and understand your pathology report. Contact us with any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

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