Monday, March 20, 2017

Case of the Week 439

This week's case is anticipation of Saturday, March 25th, in which I will be celebrating the 10-year anniversary of Creepy Dreadful Wonderful Parasites. As part of the celebration, I am asking all readers to consider sharing a photograph of your parasite creations - be it a painting, photograph, parasite-related costume, poem or other creative work. I will enter the name of each person who submits something in a drawing and will select 3 winners for creepy dreadful wonderful parasite prizes.

I have already received multiple entries, and have chosen to highlight this excellent entry from Florida Fan - a parasite kite! Can you guess the parasite?

Tuesday, March 14, 2017

Celebrating 10 Years of Creepy Dreadful Wonderful Parasites - Submit your parasite works of art to be entered in a drawing!

Dear Readers,
Thank you for all of the great suggestions on how to celebrate my 10 years of blogging. After some consideration, I've decided to use this as an opportunity to appreciate the creativity of all of my readers.

As we know, parasites can be creepy and dreadful, but they can also be wonderful and beautiful in their own right. Many of you have produced delightful parasite-related creations  - original photographs, paintings, sculptures, poems, short stories, and even kites! Therefore, please consider sharing your creations with the other readers by sending me an electronic copy of your work that I can post on my blog. I will enter the name of each person who sends me something into a drawing and select 3 individuals to receive Creepy Dreadful Wonderful Parasite prizes. I will also display all of the photos/creative works that are submitted on my blog post on March 25th, 2017 - the exact date of my 10-year anniversary.

Submissions are accepted immediately! You can submit as many as you want, but your name will only be entered once. I can't wait to see all of your works of art!

Monday, March 13, 2017

Case of the Week 438

I apologize that this week's case is rather disturbing - and not in usual the creepy crawly parasite way.

The following structure was coughed up by a 70-year-old woman with advanced stage lymphoma. She had recently received chemotherapy consisting of rituximab, ifosfamide, carboplatin and etoposide (R-ICE). At the time, she was quite ill and in the intensive care unit. Likely identification?

Sunday, March 12, 2017

Looking for Ideas - Celebrating 10 years of Creepy Dreadful Wonderful Parasites

I can't believe that my first post was almost 10 years ago now - on March 25th, 2007. I feel like I have to do something special for my 10-year anniversary on 3/25/2017.

So I'm looking for ideas. Maybe a contest with prizes? I have lots of Creepy Dreadful Wonderful Parasites 'swag' to give away, including calendars, magnets, greeting cards and iPhone cases :)

Please email me with ideas.

Answer to Case 438

Answer: Sloughed esophageal mucosa.

Although this has a superficial appearance of a worm, it actually consisted of a floppy tubular structure (not fully shown in the images) composed of the outer layer of this patient's esophagus. This is a well-described phenomenon that is most commonly seen in older patients who are receiving a number of medications. It has also been seen with infectious and bullous diseases. Here are a few references which describe this phenomenon:
Carmack et al. 2009
Purdy et al. 2012
Moawad et al. 2016
Fortunately, this is usually a self-limited condition and patients fully recover.

The following images are from a similar case that was donated by Dr. Julie Ribes.

Microscopy revealed show that the structures are composed of sheets of squamous epithelial cells.

Some readers also suggested that the original case represented mucous casts, which is another good consideration. However, mucous casts would appear more solid rather than tubular.

The most important consideration in this case is not to mistake the structures for worms, since that would lead the clinical team down the wrong path in their evaluation.

Many thanks to Dr. Ribes who provided the amazing images of her similar case, and to Dr. Grys for providing the original case.

Tuesday, March 7, 2017

Case of the Week 437

This week's case was generously donated by Dr. Mike Mitchell and Janice Gotham. This is a trichrome-stained stool specimen. While the diagnosis may seem straight-forward, there is a question in what to call this organism based on some new proposed nomenclature changes. Please tell me how you think this parasite should be reported out to the patient's physician. Dr. Stensvold, I'm particularly interested in your opinion!

Monday, March 6, 2017

Answer to Case 437

Answer: Blastocystis species

I had posed the question about nomenclature to see how labs are currently reporting this parasite when it is identified in stool specimens by microscopic examination.

Originally, only B. hominis was thought to infect humans, while other species infected other animals. However, we now know that humans can be infected with the same organisms as many other hosts, and differentiation between these species is not possible by morphologic examination alone. Therefore, the most accurate way to report this organism when observed in human stool specimens is "Blastocystis sp." rather than "Blastocystis hominis".

This may cause some confusion among clinicians and therefore, providing some education about the change is recommended.

Some other fun taxonomic facts about Blastocystis spp.:
  • It was first described by Alexeev in 1911
  • It was thought to be a yeast due to its morphologic appearance
  • Later, Blastocystis was re-classified as a sporozoan protozoal parasite 
  • Blastocystis spp. is now believed to be a stramenopile - a group that includes diatoms, brown algae and mildew. The only other stramenopile to infect humans is Pythium. (HERE is a nice article in the Journal of Clinical Microbiology about human infection with P. insidiosum)
For more information about Blastocystis spp., check out the excellent BLOG by Dr. Christen Rune Stenvold. Many thanks to Dr. Graham Clark for his assistance with describing Blastocystis taxonomy is a comprehensible fashion.

Tuesday, February 28, 2017

Case of the Week 436

This week's case was generously donated by Dr. Sabarinathan from Madras Medical College in Chennai, India. The patient is a young man with a 2-week history of epigastric pain and vomiting. Physical examination was normal, and a complete blood count showed only a mild anemia (hemoglobin of 9.8 g/dL). An ultrasound of the abdomen was normal and so an upper gastrointestinal endoscopy was performed. This is what was seen:

Monday, February 27, 2017

Answer to Case 436

Answer: Ascaris lumbricoides

Although we don't have the worms to examine in this case, the presence of multiple large tan-white worms with a smooth outer cuticle within the lumen of the intestine is strongly consistent with A. lumbricoides. The female A. lumbricoides can get quite large, reaching lengths of 35 cm!

One reader also raised the possibility of anisakiasis given that these worms were found on an upper endoscopy. However, the large size would exclude anisakid larvae given that they only reach a few centimeters in length. Also, the presence of multiple worms would be unlikely for anisakiasis, since usually only 1 larva is seen in these cases. Finally, anisakids try to recapitulate their lifecycle in their marine mammal host and embed into the gastric or intestinal mucosa. This type of behavior was not seen in this case.

Sunday, February 19, 2017

Case of the Week 435

This week's challenging case was donated by Dr. Emily Hall. The patient is a previously-healthy toddler who began acting unusually fussy and refused to ambulate. Examination reviewed a thin black object under the skin of her right foot. Extraction was unsuccessful and the child was playing and ambulating at the end of the visit and was therefore sent home. The child was brought back the following day because the object had moved approximately 3 cm within a 24 hour period in the semilunar pattern shown in the image below:
At this point, the object was removed and sent to the parasitology lab. Rather than showing you the images of the object that was extracted, I thought I would ask for your diagnosis based on the clinical image alone. I will show you the images and provide the diagnosis next week!

The image is shown with permission from the mother.