Histopathological Muscle Findings May Be Essential for a Definitive Diagnosis of Suspected Sharp Trauma Associated with Ship Strikes in Stranded Cetaceans
Figure 2
Histopathological muscle findings.
A, cross-sectional view of a skeletal muscle sample from Case No. 8. Severe diffuse interfibrilar oedema was observed. No haemorrhages were present within the sample. Fibres varied greatly in size, many being large and swollen with flocculent, granular or/and hyalinised eosinophilic sarcoplasm. HE. Bar = 100 µm; B, longitudinal section of a skeletal muscle sample from Case No. 11. The degenerated myofibres with discoid degeneration displayed partial discontinuity of the sarcoplasm, which occasionally contained lysed plasma components, and an intact basal membrane (arrowhead). Fibres in advanced degeneration frequently had the appearance of nearly empty sarcolemmal sheaths (asterisk). HE. Bar = 50 µm; C, cross-sectional view of a skeletal muscle sample from Case No. 8. Multifocal sites of severe myofibre fragmentation that were surrounded by apparently intact fibres were present within the sample. PTAH. Bar = 100 µm; D, cross-sectional view of a skeletal muscle sample from Case No. 7. Multifocal sites of severe diffuse oedema were observed. Multiple sites of fragmentation and complete disorganisation of the internal structure of the affected muscle fibres were present (arrowhead). Some fibres lacking striations had formed globes within the damaged segments (asterisk). PTAH. Bar = 50 µm. Inset: Sarcoplasmic depletion of myoglobin (arrowhead) and extracellular accumulation of this protein (red globes) was appreciable in the damaged muscle fibres. Immunohistochemistry using an antibody directed against myoglobin; E, longitudinal section of a skeletal muscle sample from Case No. 1. Detail of the discoid degeneration of the myofibres, which in this case still retained the intramyocellular glycogen deposits. PAS. Bar = 50 µm; F, cross-sectional view of fibres from Case No. 1. Both types of fibres were affected by multifocal sites of severe and extensive discoid degeneration. Immunohistochemistry using an antibody directed against type II fibres. Bar = 200 µm.