Answer to Case 123

Answer: mucus cast from stool. "Anonymous" describes it well with the following:

"Looks like a cast. The edges of the object are cracked. The best test would be apply force to see if it falls apart. Other things to look for would be mouth parts, internal structures etc."

This is correct. Even though this structure may mimic a worm, it is cracked and does not have definable head and tail structures. When force is applied using an applicator stick, it easily falls apart. Finally, the fluid surrounding the object can be examined microscopically for eggs after the object is manipulated with the applicator stick. In this case, no eggs were seen.

This type of specimen is commonly submitted to the parasitology laboratory for identification, since patients (and clinician) mistake this object for a worm. Therefore, it is important to use these simple criteria described above to differentiate a true worm from a mimic.

Thank you all for your comments!