hyaline change

• Definition : The term "hyaline" usually refers to an alteration within cells or in the extracellular space, which gives a homogeneous, glassy, pink appearance in routine histologic sections stained with hematoxylin and eosin.

It is widely used as a descriptive histologic term rather than a specific marker for cell injury. This tinctorial change is produced by a variety of alterations and does not represent a specific pattern of accumulation.

 Intracellular accumulations of protein, described earlier (reabsorption droplets, Russell bodies, Mallory alcoholic hyalin, tumoral hyaline globules), are examples of intracellular hyaline deposits.

 Extracellular hyalin has been somewhat more difficult to analyze.

• Collagenous fibrous tissue in old scars may appear hyalinized, but the physiochemical mechanism underlying this change is not clear.
• In long-standing hypertension and diabetes mellitus, the walls of arterioles, especially in the kidney, become hyalinized, owing to extravasated plasma protein and deposition of basement membrane material.

Images

 Mallory bodies in alveolar pneumocytes (chemo-related lung injury)

• https://twitter.com/smlungpathguy/status/719648662180274177

Examples

 hyaline vessels in PLEOMORPHIC HYALINIZING ANGIECTATIC TUMOR (PHAT)

• https://twitter.com/mariaramir/status/723662298389352452
• https://twitter.com/DrSampyRoy/status/733023871725494274
• https://twitter.com/DrAlodaini/status/950091320625958913
• https://twitter.com/SteveBillingsMD/status/905427241361969152

See also

 hyalinization of collagen

References

 Robbins