Trophoblast Emboli in a Chinchilla

 

History:   An 8-11 month old female intact Chinchilla had given birth to 3 baby Chinchillas 2 weeks prior.   Without any premonitory signs she “had a spasm, fell to the side and died ½ hour later”.

Gross findings:

The lungs were mottled red and pink, wet and heavy. The right cranial lung lobe was most affected.

The uterine horns contained three ½ cm round white foci that expanded the uterine wall consisting of a semi-soft material (involution of placental sites).

Histopathology:

Lungs:   There was diffuse congestion, and multifocal suppurative bronchopneumonia with edema and hemorrhage filling alveoli.  There were multifocal alveolar capillaries with 100-200 um trophoblast cells occuring singly or multiply.  The cells had abundant cytoplasm and 50-100 um diameter nuclei.   Trophoblasts were present in normal lung as well as pneumonic lung.

Lung: trophoblast embolus, H&E stain

Lung: trophoblast embolus, close up

Lung: Tropholbast embolus PAS stain

Lung: Trophoblast embolus, PAS stain, close up

Lung: trophoblast embolus, PAS stain

Uterus:  Trophoblasts were present within blood vessels of the myometrium in the uterus.

Uterus: Trophoblast embolus in myometrium, PAS stain

PAS staining has been used to outline the basement membranes of the alveolar cappillaries to demostrate the intravascular nature of the trophoblast emboli.

Comment:

The cause of death was attributed to pneumonia.  Most trophoblast emboli were present in areas with no inflammation.  In other reports of this condition in hamsters, chinchillas, and porcupines these are considered incidental findings.  In humans they have been linked to life threatening conditions.   Hemochorial placentation is common to all these species.

References:

 Hamir,  A. N. and  Rupprecht, C. E.  Trophoblast-like Cells in the Tissues of Porcupines (Erethizon dorsatum), Vet Pathol 45:409–411 (2008).

Billington, W.D. Vascular Migration of Transplanted Trophoblast in the Golden Hamster. Nature 211: 988-989 (1966).

 da Silva Ilha, M.R. et al.  Trophoblastic Pulmonary Embolism in Chinchillas (Chinchilla laniger). Ciência Rural, Santa Maria, v. 30, n.5, p.903-904, 2000.

J. D. Burek, B. Goldberg, G. Hutchins and J. D. Strandberg.  The pregnant Syrian hamster as a model to study intravascular trophoblasts and associated maternal blood vessel changes.  Veterinary Pathology, Vol 16, Issue 5 553-566, Copyright © 1979.  

Orsini MW: The trophoblastic giant cells and endovascular cells associated with pregnancy in the hamster, Cricetus auratus. Am J Anat 94:273–331, 1954.

Tvedten HW, Langham RF: Trophoblastic emboli in a chinchilla. J Am Vet Med Assoc 165:828–829, 1974.

 

Habek D, Janculjak D, Cerkez Habek J, Jalsovec D. Sudden death because of massive pulmonary thromboembolism and concomitant cerebrovascular trophoblastic embolism following artificial abortion. Fetal Diagn Ther. 2005 Sep-Oct;20(5):390-2.