Answer: Taenia saginata proglottid
There are several key morphologic features that allow for identification of this specimen. First, the presence of loose, 'myxoid' stroma, thick acellular cuticle and calcareous corpuscles allow for general identification as a cestode; in this case, a proglottid.
Next, identification of the small eggs with radial striations allow for further confirmation that this is a cestode, and identification to the Taenia genus.
Finally, the species can be tentatively identified as T. saginata, based on the presence of >13 primary branches (arrow heads) off of the central uterine stem (arrow).
Florida Fan noted that T. asiatica also has > 13 primary uterine branches and is essentially indistinguishable from T. saginata. However, Arthur rightly mentions that T. asiatica has not been described outside of Asia, presumably due to somewhat unique culinary habits of some Asian populations that include consumption of raw pig liver. Given that this patient was from Central America, she likely did not have exposure to T. asiatica, although we would need to perform molecular testing on the specimen to definitely rule out this species.