Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Dec 14 2021

Hydatid Disease

  • Snapshot
    • A 55-year-old woman comes to the emergency department complaining of abdominal pain. She states that she has suffered intermittent nausea for 2 years. Then 3 months ago she began to notice right-sided abdominal pain. She denies vomiting, diarrhea, or constipation. She has not been to a doctor in 3 years since she moved from Peru. She has had no surgeries. She takes no medications. On physical examination, there is moderate right upper quadrant tenderness. An ultrasound shows a 5-cm cyst in the right upper lobe of the liver with an irregular, calcified wall.
  • Introduction
    • Clinical definition
      • liver cyst caused by Echinococcus tapeworm
  • Epidemiology
    • Demographics
      • most common form is E. granulosus and E. multilocularis
      • usually acquired during childhood but do not manifest symptoms until adulthood
    • Risk factors
      • geographic
        • South America, Middle East, sub-Saharan Africa, and western China
        • close contacts with dogs and sheep
    • Pathogenesis
      • definitive host
        • usually dogs
      • intermediate hosts include
        • sheep, goats, camels, horses, cattle, and swine
      • transmission
        • adult tapeworm inhabits small intestine
        • produces eggs that are expelled in stool
        • eggs ingested by incidental host (fecal-oral transmission)
        • parasites hatch from eggs and penetrate intestinal mucosa to enter blood/lymphatic system
        • migrates to liver or other organs to form hydatid cysts
      • humans are incidental hosts
  • Presentation
    • Symptoms
      • mostly asymptomatic
      • if liver involved
        • 2/3 of the time
        • nausea, vomiting, and right upper quadrant pain
      • if lung involved
        • 25% of the time
        • cough, chest pain, dyspnea, and hemoptysis
    • Physical exam
      • hepatosplenomegaly
  • imaging
    • Ultrasound
      • best initial test
        • inexpensive
        • 90-95% sensitive
      • single anechoic, smooth, and round cyst
      • may have septations
      • may have a thick or irregular wall
      • “eggshell” appearance if calcified
      • may have daughter cysts (peripherally based cyst within a cyst)
    • Computed tomography or magnetic resonance imaging
      • 95-100% sensitivity
      • for greater anatomic detail to establish location and number of cysts, presence of ruptured or calcified cysts, and to guide management
      • better for evaluation of extrahepatic cysts
  • Studies
    • Diagnostic testing
      • studies
        • complete blood count
          • mild eosinophilia
          • mild elevation in liver function labs
        • serologic and antigen assays
          • i.e., enzyme-linked immunosorbent assay (ELISA)
          • can use for primary diagnosis and follow-up after treatment
          • a negative serologic test does not rule out echinococcosis
        • cyst aspiration/biopsy
          • if serologic test indeterminate/negative
          • risk of anaphylaxis and secondary spread of infection
  • Differential
    • Simple cyst
      • distinguishing factors
        • thinner wall, no calcifications, no septations, and no daughter cysts
        • sterile fluid if aspirated
        • negative serology
          • no additional tests necessary if imaging findings are consistent with a simple cyst
    • Cystadenoma or cystadenocarcinoma
      • distinguishing factors
        • rapid growth
        • tumor cells on histopathology
          • biliary-type mucus-secreting cuboidal or columnar epithelium for cystadenoma
          • malignancy changes of inner epithelial lining for cystadenocarcinoma
        • may have elevated levels of carcinoembryonic antigen (CEA)
        • negative serology
  • Treatment
    • First-line
      • albendazole
        • indication
          • single cyst < 5 cm
        • mechanism of action
          • inhibits microtubule assembly
        • adverse effects
          • hepatotoxicity
          • cytopenia
          • alopecia
          • rash
    • Second-line
      • image-guided percutaneous drainage
        • indication
          • cysts 5-10 cm
          • must be done in combination with medical therapy
        • adverse effect
          • risk of seeding
          • risk of anaphylaxis
    • Third-line
      • resection
        • indication
          • cysts > 10 cm
          • complicated cysts
            • associated with rupture, infection, compression/mass effect, biliary fistulae, hemorrhage, multiple daughter cysts, or extrahepatic cysts
        • adverse effect
          • risk of seeding and anaphylaxis less than percutaneous drainage as attempts is to resect the whole cyst
    • Other treatments
      • Mebendazole and praziquantel are less effective
  • Complications
    • Mass effect
      • Budd-Chiari syndrome
      • portal hypertension
      • cholestasis
      • cirrhosis
    • Secondary bacterial infection
    • Cyst rupture
      • presentation
        • fever
        • acute hypersensitivity reaction (i.e., anaphylaxis)
        • obstructive jaundice
        • death
1 of 0
1 of 2
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options