Zenker Degeneration

Zenker degeneration describes partial degeneration of the muscle fibre. The fibre may regenerate or the sarcolemma remains intact.

Initially there is loss of striations and hyaline change is visible histologically. The fibre will then fragment and some fragments will accumulate calcium which stains basophilic. Macrophages invade the fibres to phagocytose the degenerate muscle proteins.

If the sarcolemma is damaged then repair of the defect is by fibrosis.