Monday, October 15, 2018

Case of the Week 515

This week's case is a "worm" found in the cecum - an incidental finding during colonoscopy. It measures approximately 4 cm long. Identification? Images by my Parasitology technologist extraordinaire, Heather Rose Arguello.

Monday, October 8, 2018

Case of the Week 514

This week's case is a classic case from Heather Rose Arguello, my fabulous parasitology specialist. This is a wet preparation of liver cyst fluid (40x objective):

Sunday, October 7, 2018

Answer to Case 514

Answer: Hydatid sand of Echinococcus sp.; mostly likely Echinococcus granulosus due to the abundant protoscoleces/hooklets and presence within a single cyst. 

The photo from this case shows numerous free hooklets in the background of degenerating protoscoloces. As Blaine pointed out, the mixture of disintegrating protoscoleces with free hooklets and calcareous corpuscles is often referred to as "hydatid sand."
As Old One pointed out, the protoscoleces have a rostellum with 2 rows of hooklets - one row of large hooklets and one row of small hooklets - making this cestode "armed". He further notes that having an armed rostellum puts this cestode into the family Taeniidae.

Echinococcus species are one of several members of the Taeniidae that can cause human disease. Echinococcus granulosus is now recognized as a complex of closely-related organisms, with E. granulosus sensu stricto being the most common species causing human disease worldwide. Other members of this complex that cause human disease are E. canadensis and E. ortleppi. Differentiation of the members of the E. granulosus complex is primarily accomplished through molecular means.

E. multilocularis human infection is fortunately less common, as this parasite is known for its more aggressive and invasive growth pattern. As several readers pointed out, the cysts of E. multilocularis invade host tissue, much like a tumor, and are not contained within a large parent cyst. Protoscoleces are not commonly seen in human infections with E. multilocularis. Finally, E. oligarthra and E. vogeli are rare causes of human echinococcosis in South and Central America.

Monday, October 1, 2018

Case of the Week 513

This week features our monthly case from Idzi Potters and the Institute of Tropical Medicine, Antwerp. A Nigerian male patient, returns to Belgium, after having visited his relatives. He presents at the hospital, where a worm was extracted from his eye (length: 5 cm).
In a drop of blood, live “larvae” were seen.
A KNOTT concentration was made and stained with Carazzi’s to visualize the details.
The “larvae” are measuring (on average) 280 ┬Ám in length.

Diagnosis please?