Answer to Case 764

Answer to the Parasite Case of the Week 764: Artifact; not a human parasite. This material closely resembles plant spirals. This was a challenging case to be sure! However, there were a few clues that can help us out here:

First, note that the outer contour of these worm-like objects consists of spiral, refractile rings that look a bit like a 'slinky' (for those of you who remember those old toys!)

What appears to be internal nuclear material is just multinucleated giant cells from the host. 

Second, I mentioned that numerous foreign body giant cells and 'pulse granulomas' were seen on histopathology. Pulse granulomas are granulomas associated with a foreign-body reaction and often contain identifiable vegetable material. The term 'pulse' refers to the edible seeds of leguminous vegetables. The presence of vegetable material elsewhere in this specimen support our diagnosis of vegetable spirals here. 

For further confirmation, I turned to our friend and botany expert, Dr. Mary Parker, for her advice on this case. She indicated that we are likely seeing xylem vessels with spiral thickenings from plant vascular bundles (veins). She noted that "the simple spiral thickening in the above is typical of plant material such as young leaves (i.e. not as heavily thickened as in woody material), whereas the xylem thickenings in the colon wall are much more heavily lignified, indicating more mature plant material." She also explained that "young leaves like spinach, lettuce and parsley will all have a mixture of lightly and more-heavily thickened xylem." I remember learning about xylem and phloem back in primary school, but I never thought they would be useful in parasitology. Many thanks to Mary for her input, and kudos to Idzi for getting this case correct!

Check out the beautiful xylem spirals from this POST.

Wishing you all a very happy, healthy, peaceful, and productive new year.