Abstract
Thymic cysts have not been previously reported in harbor porpoises (Phocoena phocoena). Two hundred forty stranded or "by-caught" harbor porpoises originating from the German North Sea and Baltic Sea and 14 animals from the waters of Greenland were necropsied. Thymuses of 78 porpoises of the North Sea and Baltic Sea were considered suitable for histopathologic examination based on the extent of postmortem autolysis. Immunohistochemistry using an anti-cytokeratin antibody was employed to demonstrate thymic epithelial structures in selected cases. Thymic macrocysts were rare and were only found in animals ≥7 years of age. Thymic: microcysts, lined by a single cytokeratin-positive cell layer, were common in involuting thymuses, and the prevalence increased with advancing age. Thymic cysts might have arisen from degenerating Hassall's corpuscles or condensed epithelial reticulum. Thymuses were easily identified macroscopically in most adult healthy harbor porpoises, suggesting that physiological thymic involution proceeds slowly in this species.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 391-396 |
| Number of pages | 6 |
| Journal | Veterinary pathology |
| Volume | 36 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1999 |
Bibliographical note
Funding Information:We thank A. Artelt for technical assistance, L. Chavez-Lisambart for age determination, I. Blaha and R. Weiss for microbiological examinations, M. P. Heide-Jorgensen for providing samples of the animals from waters of Greenland, and K. Failing for support in statistical analysis. The studies were supported by the Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit and the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie, Germany.
Keywords
- Cetacea
- Harbor porpoises
- Thymic cysts
- Thymic involution