PARENCHYMAL LESIONS OF THE LIVER
A 36-year-old woman presents to the emergency room with hypotension, severe right upper quadrant (RUQ) abdominal pain, and one episode of emesis. She is in the second trimester of her first pregnancy, and her last prenatal note states that she was to be scheduled for an ultrasound study due to mildly elevated liver function tests and 3 to 4 days of right upper quadrant pain that worsens with lying on the right side. She had previously used oral contraceptives for approximately 20 years. She has a history of appendectomy performed approximately 3 weeks previously. An ultrasound study demonstrates a gravid uterus with a viable intrauterine pregnancy consistent with dates. During a focused assessment with sonography for trauma (FAST) examination, a liver mass is observed while imaging the hepatorenal recess. Upon arrival, vitals are T 99.0°F, HR 113, BP 104/54, RR 26, and SaO2 96%. She looks unwell and is mildly tender in the RUQ. Labs are pending.
Parenchymal lesions of the liver may be broadly grouped into neoplastic and non-neoplastic categories. Neoplastic lesions may be tumors, either benign or malignant; non-neoplastic lesions include hepatic cysts and abscesses. Many of these lesions are diagnosed after extensive multidisciplinary workup; however, certain diagnoses are associated with key imaging findings and may present acutely. For purposes of this section, we review three parenchymal lesions that may present for acute surgical evaluation in the emergency room: hepatic abscesses, symptomatic liver cysts, and ruptured hepatic adenoma.
Liver abscesses are the most common type of visceral abscess. Pyogenic abscesses account for nearly half of all visceral abscess, and more than 10% of all intra-abdominal abscesses in one large series.1 Historically, most pyogenic abscesses occurred after an intra-abdominal infection such as ruptured appendicitis; however, among patients with access to modern surgical and antibiotic therapy, the incidence of pyogenic abscess secondary to primary intra-abdominal infection has decreased. However, the overall incidence of pyogenic abscess has not decreased over the past 50 years, and may have increased.2 Notably, the patient population affected by hepatic abscess has changed dramatically, with increasing proportions of patients that are older, have underlying malignancy or immunocompromise, or have undergone biliary instrumentation. Ascending hepatic infection secondary to biliary obstruction is now increasingly common, particularly as the management of biliary tract pathology has grown increasingly sophisticated, and as endoscopic and percutaneous techniques within the diagnostic and therapeutic armamentarium have expanded. Risk factors for hepatic abscess include biliary or pancreatic disease and immunosuppressed states such as diabetes or transplantation.3
Simple cysts are uncommon before age 40. The female-to-male ratio is 1.5:1 for asymptomatic simple cysts at autopsy or on ultrasound, but 9:1 in symptomatic or complicated cysts. Parasitic echinococcal disease is relatively uncommon in the United States, but is more ...