Cysticercus tenuicollis vesicle in fetal structures: report of a case.

Cysticercus tenuicollis is the larval stage of the canine tapeworm Taenia hydatigena, the presence of which has been reported in wild and domestic ruminants all over the world. It is a common parasite of small ruminants in the north of Portugal. C. tenuicollis is generally seen attached to the omenta, the mesenteries or also found in the liver. In the ewe, tissue lesions have been associated with degenerative cysts or with oncosphere migrations. Unusual locations of the cysticerci of T. hydatigena have been described. The most frequent unusual locations are in the lungs, the kidneys and the brain. Less common locations have been reported to occur in the ovaries, uterine tubes, uterus, cervix and vagina. In the case described here, and for the first time, an aberrant location of a C. tenuicollis vesicle was found inside the chorion-allantoic membrane of a goat's foetus, in a gemelar gestation of approximately 70 days. Finding a C. tenuicollis vesicle inside fetal membranes forewarns of the possibility of larval migrations into the fetal structures during pregnancy, which is particularly concerning in human populations that are infested.