Trophoblast-like Cells in the Tissues of Porcupines ( Erethizon dorsatum )

Abstract

During development and subsequent field evaluation of an oral vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine, 53 adult porcupines ( Erethizon dorsatum; 38 females and 15 males) were examined. Microscopic examinations revealed the presence of giant epitheloid cells in various tissues (adrenal glands, spleen, liver, and lungs) of 4 (11%) female animals. These giant cells were approximately 20 times the size of the surrounding cells of the parenchyma. The cells were found singly and were not associated with any inflammatory cellular infiltrate and appeared to be located within vascular lumina. Morphologically these cells were typical of uterine epitheloid trophoblasts. This is the first record of the presence of trophoblast-like cells in nongenital tissues of porcupines.