Monday, January 20, 2020

Case of the Week 577

This week's very cool case was donated by Dr. Mike Feely. We haven't had anything like this one before on the blog!

The specimen below was submitted by a young woman who found this "worm" by her arm, right below her mouth, upon waking from a nap. She reported having abdominal pain with associated diarrhea for several weeks prior to presentation, but was otherwise healthy.

 After being in formalin:

Histologic sections (H&E):

Identification? Any additional information that you would like?


Old One said...

Do you know the location of host?

Was critter motile when found?

Was there any unusual morphology associated with critter's anterior?

Was host doing gardening or other outdoor activity prior to nap?

Anonymous said...

The external appearance is that the specimen is flat, there may be a missing anterior or posterior. The internal morphology from the cross section HE stain suggests that the specimen may have a digestive tract. Overall, this "worm" is not compatible with any platyhelminthes we are familiar with, it rather is suggestive with an incidental find of possibly a slug.
Florida Fan

Old One said...

Appears to be a nonparasitic terrestrial invertebrate. A terrestrial or hammerhead planarian.

Blaine A. Mathison said...

Looks like a planarian in the genus Bipalium.

Crabby said...

Looks like a hammerhead planarian. Bipalium sp.

Debra V said...

I think it looks like a large pice of mucous filled with stool

Bernardino Rocha said...

Agree with a hammerhead planarian. I can´t tell the genus but probably, as referred, a Bipalium sp. or Diversibipalium sp. Great and unusual case.

Anonymous said...

Going off what others said about the organism being a land planarian, I found an article with some anatomy for comparison Morffe, J. et al, BioInvasions Records (2016) Volume 5, Issue 3: 127–132 DOI:

The anatomy from picture 5 matches rather nicely Figure 2a Transverse section at level of the pre-pharyngeal region. The most obvious features are the muscles and the glandular canal. Looking more closely I can match the pale foamy nerve cord. The histology in both the images have gaps in the tissue, I suspect that the planarian was not well preserved. Tissue sections must be cut thin enough for the both formalin fixation and tissue processing. In Anatomic Pathology residents have drilled into them that formalin fixation is a slow process.

All in all, not a parasite.


Ilze said...

Hammerhead planarian. Was the patient maybe taking a nap in the garden? ��