Mucoid Degeneration

Introduction

  • Mucoid degeneration is also known as mucinous or myxomatous degeneration.
  • Mucoid degeneration involves changes in epithelial tissue or the extracellular matrix/ ground substance.
  • An extracellular phenomenon of some specific cells.
    • Tend to show a bluish tinge in H&E stained sections.

Epithelium

  • The specific cells involved in mucoid degeneration in the eptihelium are:
    • The goblet cells of wet mucous membranes.
    • The mucous glands themselves.
  • This is not really a degeneration, but an increased production of mucin.
    • It is a beneficial reaction; the product
      • Is important as a lubricant.
      • Soothes inflamed surfaces.
      • Traps and dilutes harmful agents.
      • Carries specific antibodies against infectious agents.
      • Provides a means for removal of infectious agents.


Connective tissue

  • Here, the mucin forms part of the ground substance between the fibroblasts that produce it.
  • A disturbance in the metabolism of the fibroblasts under some circumstances,means the ground substance takes on a bluish hue in H&E sections.
  • Mucoid degeneration in the heart valves of middle-aged and older dogs is a common example.
    • Causes endocardiosis.
      • A condition specific to the dog.

Endocardiosis