Cystic medial degeneration

Cystic medial degeneration (abbreviated CMD), also cystic medial necrosis, is vascular pathology of the large blood vessels. It is suggestive of an underlying connective tissue disorder.

General

• Nonspecific finding - may be seen in a number of conditions.
• "Medial" refers to tunica media the middle (muscle) layer of an artery.

Note about cystic medial necrosis:

• Often not cystic and not necrotic.

Microscopic

Features:

• Basophilic ground substance in the media (seen on Movat's stain).
• Disruption of the elastic lamina (seen on elastic trichrome stain).
• +/-Focal necrosis.

DDx:

• Aortic dissection without apparent underlying pathology.

Images

• 

  Cystic medial degeneration - low mag. (WC/Nephron)

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  Cystic medial degeneration - high mag. (WC/Nephron)

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  Cystic medial degeneration - movat - low mag. (WC/Nephron)

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  Cystic medial degeneration - movat - intermed. mag. (WC/Nephron)

www:

• Marfan's syndrome (radiographics.rsna.org).

Stains

• Elastin stains (e.g. elastic trichrome stain) - disruption of the elastic lamina.
• Movat's stain - basophilic ground substance in the media.
• Alcian blue-PAS.

Images

• CMD - Alcian blue-PAS (unibas.ch).
• CMS - Alcian blue-PAS (unibas.ch).
• CMS - Alcian blue-PAS (unibas.ch).

See also

• Vascular disease.
• Aortic dissection.