Myxomatous degeneration

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Myxomatous degeneration of heart valves is rare benign condition that is typically seen in the mitral valve, and may be associated with various genetic conditions.

Myxomatous degeneration
Diagnosis in short

Myxomatous valve. Movat stain. (WC)

LM thinning of fibrosa layer, thickening of spongiosa layer with mucoid (myxomatous) material, +/-secondary changes due to valvular dysfunction (e.g. thrombi, fibrosis)
Stains Movat stain - to demonstrate mucoid material
Gross valve thickened, rubbery consistency, reactive/secondary changes common (fibrosis due to prolapse/abnormal contact of valve with other structures, clots/organized thrombus due to stasis)
Grossing notes Mitral valve grossing
Site heart valve, typical mitral valve

Syndromes Marfan's syndrome, Turner syndrome

Prevalence uncommon
Treatment surgical replacement

General

Gross

Features:[4]

  • No commissural fusion.
    • Commissural fusion typical of rheumatic heart disease.
  • Thickened.
  • Rubbery consistency.
  • Reactive/secondary changes.
    • Fibrosis due to prolapse/abnormal contact of valve with other structures.
    • Clots/organized thrombus - due to stasis.

Microscopic

  • Thinning of fibrosa layer.
  • Thickening of spongiosa layer with mucoid (myxomatous) material. (key feature).
  • +/-Secondary changes (due to valvular dysfunction): thrombi, fibrosis.

Staining

  • Movat stain.
    • Acid fuchsin, alcian blue, crocein scarlet, elastic hematoxylin, pathology consultation, and saffron.[5][6]

Interpretation of Movat stain:[6]

  • Black = nuclei and elastic fibers.
  • Yellow = collagen and reticular fibers.
  • Blue = mucin, ground substance.
  • Red (intense) = fibrin.
  • Red = muscle.

Image

See also

References

  1. URL: http://emedicine.medscape.com/article/759004-overview. Accessed on: 8 June 2010.
  2. Leong SW, Soor GS, Butany J, Henry J, Thangaroopan M, Leask RL (October 2006). "Morphological findings in 192 surgically excised native mitral valves". Can J Cardiol 22 (12): 1055-61. PMID 17036100.
  3. Wigle ED, Rakowski H, Ranganathan N, Silver MC (1976). "Mitral valve prolapse". Annu. Rev. Med. 27: 165–80. doi:10.1146/annurev.me.27.020176.001121. PMID 779595.
  4. Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 591. ISBN 0-7216-0187-1.
  5. URL: http://www.mayomedicallaboratories.com/test-catalog/Overview/9832. Accessed on: 8 June 2010.
  6. 6.0 6.1 Modified Movat's Pentachrome Stain. University Penn Medicine. URL: http://www.med.upenn.edu/mcrc/histology_core/movat.shtml. Accessed on: January 29, 2009.