This week's case was donated by Heather Morris, the parasitology lead in my laboratory. We received the following objects for identification:
Subscribe to:
Post Comments (Atom)
skip to main |
skip to sidebar
A parasitologist's view of the world
Welcome to Parasite Case of the Week
Every week I will post a new Case, along with the answer to the previous case. Please feel free to write in with your answers, comments, and questions. Also check out my image archive website at http://parasitewonders.com. Enjoy!
The Fine Print:
Please note that all opinions expressed here are mine and not my employer. Information provided is for educational purposes only. It is not intended as and does not substitute for medical advice. I do not accept medical consults from patients.
The Fine Print:
Please note that all opinions expressed here are mine and not my employer. Information provided is for educational purposes only. It is not intended as and does not substitute for medical advice. I do not accept medical consults from patients.
About Me
Top 50 Pathology Blog
8 comments:
Gross appearance of a tape worm. The first step we would take is to visualize the vagina position. The second step is to press a proglottid for an examination of eggs. Next we need to look for its scolex and if not found, an injection of India ink to visualize and uterine branches count. Lastly a Semichon Carmine stain for examination of internal anatomy. Even in the first step the length of a tapeworm would give an idea of its probable identity.
Florida Fan
Agree with FF, we call it "raping the tape worm" but do we really care in a clinical sense. i.e. why should we really pursue?
Press it out on a slide, add potassium iodine and look for eggs. /Patrik
If the eggs look like Taenia, we might also send to the public health agency for PCR, if the hospital/primary care is interested in that.
/Patrik
The tapeworm in the picture resembles a Taenia species, probably saginata. Taenia saginata is more commonly found in humans than solium or asiatica. Though less commonly found, Taenia solium does pose more serious diseases with cysticercosis or neurocysticercosis.
Florida Fan
I love when this specimens arrive to the lab!
We first check if it's really a parasite segment, sometimes patients bring undigested foods or mucus structures, so we move them a bit with a wooden stick (food or mucus will segregate, parasite will maintain it's form). Then we check for eggs, most of the time we use the liquid on the original container or squeeze some eggs from the proglottid (the specimens we get are Dibothriocephalus most of the time). And if there are Taenia sp eggs, we squeeze a proglottid with Lactophenol blue (too hard to try inject Indian ink and often we get a black mess) between 2 thick pieces of glass, if done correctly, you can see the uterine branchs with a back light.
We are very careful with these specimens, it could be Taenia solium and the eggs could cause Cysticercosis, don't manipulate without PPE.
-HLCM fan
I do not know if there is any fan of the Pathology HE stain modified to stain parasites specimens like Taenia proglottid or Chlonorchis sinensis but, when properly done the internal anatomical organs are very well stained and visible.
Florida Fan
Beautifully gross! ;-)
I just love it when such a thing gets into my hands!
For sure a tapeworm!
The size places it at either Dibothriochephalus sp. or Taenia sp.
The terminal segment seems to have a laterally positioned uterine pore in the presented image, which excludes Dibothriocephalus already (which would have it centrally on the proglottid's surface in fact). If the pore isn't very well visible, one could use the general shape of a mature (!) segment: longer than broad = Taenia, while broader than long = Dibothriocephalus, but this may be tricky if one isn't sure if the segments are (im)mature...
In case of Taenia sp: we should try to make the distinction T. saginata vs T. solium vs T. suihominis (formerly T. asiatica), because T. solium eggs will cause (neuro)cysticercosis when ingested by humans, with possibly very severe consequences! First step in our lab: When the proglottid is mature/gravid AND mobile, then it is identified as T. saginata. With the caveat that longer chains of (immature or non-gravid) segments (as in this case) may move as well, but are not per sé T. saginata in that case. So more reliable in this case (or when segments do not move): one can look at the inner structure of a mature segment to count the number of unilateral uterine ramifications (>13 = T. saginata / T. suihominis ; <13 = T. solium). In our lab, we press the segment between glass slides and hold it against back-light to check this. This usually does the trick. When the patient has traveled to / originates from Asia, this would open the possibility for T. suihominis as well. T. suihominis segments would be morphologically comparable to T. saginata. When the T. suihominis possibility comes into play, or when there is even the slightest doubt on the morphology/motility, molecular differentiation is the safest option.
Nice case! Thanks for sharing!
Post a Comment