Difference between revisions of "Masticatory Muscle Myositis"
Jump to navigation
Jump to search
LisaMilella (talk | contribs) |
|||
| Line 9: | Line 9: | ||
*Grossly: | *Grossly: | ||
**Bilateral but not necessarily symmetrical | **Bilateral but not necessarily symmetrical | ||
| − | |||
*Histologically: | *Histologically: | ||
**Acute lesions: | **Acute lesions: | ||
Revision as of 13:52, 4 August 2014
(MMM)
- Occurs in dogs
- Tends to affect the masseter and temporalis muscles
- Autoantibodies selectively attack muscles of mastication (type IIM fibres)
- Acute stage = eosinophilic myositis
- Extremely swollen, painful, hard masticatory muscles
- Chronic stage = atrophic myositis
- Atrophy may occur without previous acute stage
- Grossly:
- Bilateral but not necessarily symmetrical
- Histologically:
- Acute lesions:
- Mainly eosinophilic infiltrate, few lymphocytes, monocytes and plasma cells
- In recurrent disease plasma cells predominate
- Necrotic myofibres, atrophy and attempted regeneration
- Chronic stage:
- Atrophy predominates
- Fasciculi are shrunken
- Condensation of stroma -> enlarged endomysium
- Focal plasma cell and lymphocyte infiltration
- Acute lesions: