Extralobar pulmonary sequestration in two pinniped species

Area of Science:

• Veterinary Pathology
• Comparative Anatomy
• Wildlife Biology

Background:

• Extralobar pulmonary sequestration is a rare congenital anomaly.
• Documenting congenital anomalies in wildlife is crucial for understanding population health.
• Pinnipeds, like walruses and Steller sea lions, are susceptible to various health conditions.

Observation:

• Two cases of extralobar pulmonary sequestration were identified in a walrus (Odobenus rosmarus) and a Steller sea lion (Eumetopias jubatus).
• Gross examination revealed independent, cystic masses within the abdominal cavities, attached to the diaphragm and stomach cardia, respectively.
• Histopathological analysis showed cysts lined by ciliated columnar epithelium with goblet cells and walls containing glandular, cartilaginous, and vascular structures.

Findings:

• The identified masses exhibited features consistent with extralobar pulmonary sequestration.
• The unique anatomical locations and detailed histopathology provide new insights into this anomaly.
• These are the first reported cases of extralobar pulmonary sequestration in these specific pinniped species.

Implications:

• This research expands the known spectrum of congenital anomalies in marine mammals.
• Understanding such conditions in wildlife is vital for conservation and veterinary care.
• The findings contribute to the broader knowledge of comparative pulmonary development and pathology.