A 37-year-old woman comes to the office due to right-sided abdominal discomfort that has been getting progressively worse over the past few weeks. She has not had any nausea or vomiting. The patient's family moved to the United States from rural Kazakhstan when she was a child. The patient has no drug allergies. She does not use tobacco or alcohol. She has a dog at home. Temperature is 36.7 C (98.1 F). Physical examination is notable for hepatomegaly. Ultrasound reveals a large liver mass with cystic lesions. During surgery to resect the mass, the patient suffers from a procedural complication and dies. At the family's request, an autopsy is performed. A cut section of a portion of the mass is shown in the image below. Which of the following is the most likely cause of this patient's death?

Question

A 37-year-old woman comes to the office due to right-sided abdominal discomfort that has been getting progressively worse over the past few weeks.  She has not had any nausea or vomiting.  The patient's family moved to the United States from rural Kazakhstan when she was a child.  The patient has no drug allergies.  She does not use tobacco or alcohol.  She has a dog at home.  Temperature is 36.7 C (98.1 F).  Physical examination is notable for hepatomegaly.  Ultrasound reveals a large liver mass with cystic lesions.  During surgery to resect the mass, the patient suffers from a procedural complication and dies.  At the family's request, an autopsy is performed.  A cut section of a portion of the mass is shown in the image below.  Which of the following is the most likely cause of this patient's death?

Quizplus · Accepted Answer

The tapeworm Echinococcus granulosus is the most common cause of hydatid cysts. Most cases occur in individuals from endemic regions (eg, eastern Mediterranean, Middle East, South America, sub-Saharan Africa, former Soviet Union, western China) or those residing in the southwestern United States with sheep and dog (participate in the tapeworm life cycle) exposure. Initial infection is generally asymptomatic, with subsequent manifestations depending on cyst location and size. The liver is often affected (leading to hepatomegaly or right upper quadrant pain), but other organs such as the lungs or muscles can be involved. Unilocular lesions are typical of E granulosus, and multilocular lesions are typical of E multilocularis. When infection occurs, echinococcal larvae implant within the capillaries, triggering an inflammatory reaction involving monocytes and eosinophils. Some larvae encyst. Microscopic examination demonstrates an encapsulated and calcified cyst ("eggshell calcification") containing fluid and budding cells that will eventually become daughter cysts. The outer wall is composed of gelatinous sheets surrounded by a thick fibrous capsule. Imaging (ultrasound, CT, MRI) and serology testing can be used for diagnosis. Depending on the size of the cyst, surgery and adjunctive chemotherapy (eg, albendazole) are the treatment of choice for symptomatic patients. Cyst manipulation (eg, surgery, aspiration) should be performed with caution, as spilling of cyst contents can cause anaphylactic shock, which likely occurred in this patient. (Choices B, C, D, and E) Fulminant liver failure can arise due to numerous conditions, including viral hepatitis, acetaminophen toxicity, idiosyncratic drug reactions, or Wilson disease. Hypovolemia is typically caused by severe blood loss, although excessive loss of other bodily fluids (eg, diarrhea, vomiting, burns, dehydration) may also be responsible. Pulmonary emboli are typically caused by the propagation of venous thrombi, with less common sources including air bubbles, fat droplets, amniotic fluid, or clumps of parasites or malignant cells. Overwhelming systemic infection with bacterial organisms can cause septic shock (hypotension, low blood flow). None of these conditions is typically associated with hydatid cysts. Educational objective: Echinococcus granulosus is the most common cause of hydatid cysts. Spilling of cyst contents can cause anaphylactic shock. Surgical manipulation should be performed with caution.

A 37-Year-Old Woman Comes to the Office Due to Right-Sided