Perhaps it’s appropriate to have a GI case since we just finished our big Thanksgiving meals (in the states, that is). Take a look at the photos and the question, then scroll down for the answer. A 52-year-old male presents with abdominal pain and bloody diarrhea which had a gradual onset over the last 3 weeks. He has lost 8 pounds during this period of time. A cecal biopsy is performed, and a representative section is shown here at two magnifications. 

Unknown 15_5

What is the most likely diagnosis?

A. Cryptosporidiosis
B. Amoebiasis
C. Giardiasis
D. Ascariasis
E. Candidiasis






(Scroll down for the answer)








The diagnosis in this case is amebiasis. The most common agent of amebic enterocolitis is Entamoeba histolytica, an tiny parasite spread through ingestion of cysts in contaminated food or water. The trophozoite forms are round, and if you look closely, you can often see intracytoplasmic red cells, as seen in the higher power image above.

Unknown 15 3

The organisms frequently invade through the mucosa and into the submucosa, often with lateral extension, as seen in this image. Lesions like this are sometimes called “flask-shaped ulcers.” Occasionally, the nasty little thing invade other organs, such as the liver, lung, and heart. Most patients can be treated on an outpatient basis, unless there is severe colitis or extraintestinal disease.

If you liked this case, and want to test yourself with other unknown cases, here are some to try:

  • Case 1: 20-year-old male who died suddenly
  • Case 2: 72-year-old male with right calf mass
  • Case 3: 67-year-old female with pancytopenia
  • Case 4: 59-year-old male with severe headaches
  • Case 5: 38-year-old female with deep venous thrombi
  • Case 6: 13-year-old male with cerebellar mass
  • Case 7: 45-year-old male with pulmonary emphysema
  • Case 8: 38-year-old male with AIDS and headaches
  • Case 9: 25-year-old male with arm mass
  • Case 10: 57-year-old male with fatigue and left upper quadrant heaviness
  • Case 11: 62-year-old male with hepatosplenomegaly, skin lesions and cardiomyopathy
  • Case 12: 16-month-old infant with failure to thrive
  • Case 13: 36-year-old female with painless lower leg nodule
  • Case 14: 58-year-old female with several-year history of pelvic pain