A 34-year-old woman comes to the office due to sudden onset epigastric pain radiating to the back, nausea, and vomiting. Her medical history is significant for major depression, generalized anxiety, and irregular menses. She takes sertraline and an oral contraceptive. The patient describes occasional heavy alcohol use and drinks hard liquor daily. She does not use tobacco or illicit drugs. Temperature is 37 C (98.6 F), blood pressure is 120/80 mm Hg, pulse is 98/min, and respirations are 18/min. BMI is 24 kg/m². No jaundice is present. Examination shows epigastric tenderness. Serum lipase levels are markedly elevated. Abdominal ultrasonogram reveals an enlarged pancreas, no gallstones, and normal gallbladder; a mass is also noted in the right lobe of the liver. Subsequent abdominal CT scan reveals a well-circumscribed, 5-cm mass with a central scar that appears hypodense on noncontrast imaging. Imaging with contrast indicates the lesion is hyperdense. The rest of the liver appears to be normal, and there is no intra- or extrahepatic duct dilatation. Which of the following is the most likely diagnosis for the liver lesion?

Question

Quizplus · Accepted Answer

11ec25c8_d87c_d7e3_bc81_fddc05766260_MD0003_00 This patient's heavy alcohol use, acute epigastric pain radiating to the back, elevated lipase, and enlarged pancreas indicate acute pancreatitis. The presence of a well-circumscribed liver lesion with a central scar likely represents an incidental finding of focal nodular hyperplasia (FNH), a benign regenerative liver nodule common in women age 20-50. Most cases of FNH are asymptomatic and are discovered during abdominal imaging for other conditions. Lesions tend to be well-circumscribed, solitary, and <5 cm in size; they characteristically have a central, stellate scar, which surrounds a large congenital arterial anomaly that sends arterial branches to the periphery. Imaging with triphasic, helical CT scan (which evaluates the mass during different phases of vascular contrast) generally reveals a hyperdense lesion (ie, filled with contrast during hepatic arterial phase) and a central scar. Because FNH does not generally grow over time, undergo malignant transformation, or rupture, treatment is rarely required. Oral contraception is not believed to worsen FNH; therefore, contraception usually can be continued (in contrast to hepatic adenoma). (Choice B) Hepatic hemangioma, the most common benign liver tumor, is often found incidentally during imaging for other conditions. However, triphasic CT scan will reveal centripetal enhancement (ie, enhancement moving from periphery to center) and no central scar. (Choice C) Hepatic adenomas are benign liver tumors that often arise in the right lobe of the liver in women on oral contraception (possibly due to effects of estrogen on hepatocyte, although studies have been inconclusive). However, centripetal enhancement is usually seen on triphasic CT scan, and no central scar would be present. (Choice D) Hepatocellular carcinoma is a malignant liver tumor that usually arises in the setting of chronic liver disease (eg, cirrhosis, viral hepatitis). Patients are often asymptomatic but may develop weight loss or early satiety. Although hepatocellular carcinoma enhances with contrast, a central scar is atypical. (Choice E) Hepatic cirrhosis is common in individuals who consume excessive amounts of alcohol. Nonspecific symptoms (eg, fatigue, weight loss) often occur, and patients may develop ascites, hepatic encephalopathy, or jaundice. Cirrhosis is marked by hepatic fibrosis, distortion of normal hepatic architecture, and regenerative nodules, so imaging generally reveals a shrunken, irregular liver with innumerable small nodules. (Choice F) The liver is a common site of metastases from a wide range of tumors (eg, pancreatic, colorectal, breast). Although solitary lesions can occur, multiple lesions are most common. In addition, a central scar would be atypical. Educational objective: Focal nodular hyperplasia is a benign liver lesion due to an aberrant congenital artery. It is usually found incidentally in young women and is marked by the presence of a stellate central scar and radiating fibrous bands.

A 34-Year-Old Woman Comes to the Office Due to Sudden