Table 4 Histological changes in the 32 Hungarian Vizslas with biopsy-confirmed polymyopathy
From: Clinical features of idiopathic inflammatory polymyopathy in the Hungarian Vizsla
Histopathological changes (Total 32) | Group 1 | Group 2 |
|---|---|---|
25 total dogs (biopsies) (confirmed VIP diagnosis) | 7 dogs (3 biopsies, 1 biopsy and post-mortem/3 post-mortem) (myopathy diagnosis) | |
Inflammatory change e.g. Lymphohistiocytic inflammation | Variability in myofibres size with multifocal endomysial, interstitial and perivascular mononuclear cell infiltrations (lymphocytes & macrophages +/− plasma cells, eosinophils) of non-necrotic fibres. Underlying inflammatory process masked by corticosteroid treatment in one case. |  |
25 dogs | 0 dogs | |
Myopathic change | Â | Variation in the myofibre size without inflammatory infiltration. |
0 dogs | 7 dogs | |
Adipose tissue | Small amount of adipose tissue associated with fibrosis. | Adipocytes present in some fascicles (endomysium and perimysium). |
2 dogs | 1 dogs | |
Fibrosis | None OR perimisial/endomysial fibrosis OR occasionally area of fibrosis with lack of myofibres with any significant inflammation (primary or secondary?) | Â |
3 dogs | 0 dogs | |
Degenerative changes | Either any appreciable myofibre degeneration or active degenerative changes within the muscle fibres (variation in myofibre diameter, atrophy with round to polygonal/angular shape, hyalinisation, nuclear internalisation, sarcolemmal fragmentation). | Variation in muscle fibres, atrophy (occasionally smaller fibres grouped together, some angular but most round to polygonal profile), nuclear internalisation. |
19 dogs | 4 dogs | |
Regenerative changes | Nuclear rowing, centralisation/hyperthrophy of the nuclei increased cytoplasmic basophilia, type 2 fibres. | Occasional enlarged and round myofibres (compensatory hypertrophy), and nuclear rowing. |
13 dogs | 3 dogs | |
Necrotic fibres | Scattered to severe necrotic myofibres with some undergoing phagocytosis. | Â |
7 dogs | 0 dogs | |
Fibrosis | Mild to moderate endomysial and perimysial fibrosis secondary to myofibre loss. | Increased endomysial and perimysial connective tissue secondary to myofibre loss. |
7 dogs | 2 dogs | |
Intramuscular nerve branches | Normal (25 dogs) | Normal (7 dogs) |
Immunoreagent SPA-HRPO | Present in two cases | Â |
(Antibodies against endplate proteins) | ||
Dystrophin protein | Â | Decreased staining for carboxy terminus of the dystrophin protein was found in one case; however, the dog improved on immunosuppressive treatment and the suspicion for muscle dystrophy was abandoned. |