Digital Case Challenge: Enterobius vermicularis (Pinworm)
Posted Dec 06 2010 1:29pm
The day before the (U.S.) Thanksgiving, I saw this case. It was identified as simply "colon biopsy" but the pathology assistant noted white thready "mucosal" fragments measuring about 4 mm to 5 mm in length.
The ova are usually described as being about 30 X 50 microns but I think these are slightly smaller due to formalin fixation and routine processing, while this diagnosis is usually made by the "Scotch tape" technique pressed onto perianal skin. Uncommon as a colonoscopic specimen. This parasite is transmitted by a fecal-oral route and does not require an intermediate host. Didn't obviously want to post this around the holiday.