A patient presents with diarrhea, recent travel, and RUQ pain with a cystic abdominal mass found on CT. What is the likely diagnosis?

• A. Cholecystitis
• B. Entamoeba histolytica
• C. Giardia lamblia
• D. Hepatitis A

Answer: (B)

The presentation of diarrhea, recent travel, right upper quadrant (RUQ) pain, and a cystic abdominal mass found on CT strongly suggests an infection with Entamoeba histolytica, leading to amoebic liver abscesses.

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and can also lead to serious extraintestinal complications, particularly in individuals who have recently traveled to areas where the parasite is endemic. The cystic mass observed can represent an amoebic abscess in the liver due to the spread of the infection from the intestinal tract to the liver, which is not uncommon in cases of severe infection.

The combination of gastrointestinal symptoms, travel history, and the presence of a cystic mass aligns well with this diagnosis, as the parasite can invade the intestinal mucosa causing diarrhea and subsequently can migrate to the liver, leading to the formation of abscesses.

In contrast, other options would not typically present with this specific combination of symptoms and findings. Cholecystitis is more localized to the gallbladder area and usually presents with different types of abdominal pain and fever, while Giardia lamblia infection primarily causes diarrhea without the cystic mass on imaging. Hepatitis