Answer to Case 799

 Answer to Parasite Case of the Week 799: Not a parasite; plant material consistent with guar gum.

Guar gum (a.k.a. guaran) is a galactomannan polysaccharide extracted from guar beans. It has thickening and stabilizing properties that are useful for food, feed, and industrial applications. In medicine, it is often used as an adhesive to keep ostomy bags attached to the skin. This is how it likely got into the specimen from this patient. 

Some readers queried if this plant material could have originated from the intestinal tract, given that the patient has an ileal conduit. However, in looking into the way an ileal conduit is created, we can see that it is disconnected from the GI tract and therefore would not contain food material.

For fun, I decided to investigate the microscopic appearance of guar gum using common parasitology stains. Below are my results using a simple wet prep, modified trichrome (Ecostain) stain, and Giemsa stain. Note that it is birefringent with polarized light, as is most plant material. 

This interesting finding has been reported before by Nomani et al. Thanks again to Drs. Rattin and Shah for donating this interesting case!