A 21-year-old man presents to the emergency room with right lower quadrant pain that started this afternoon at his wrestling match. He also endorses loss of appetite and subjective fever. He has had vague, mild discomfort in the right upper quadrant since the start of this wrestling season. He endorses a history of unprotected sex with multiple partners and intravenous drug use during a recent vacation to Mexico but has no other significant medical history. He drinks socially and has never smoked. His temperature is 98.6°F (37°C), blood pressure is 119/72 mmHg, pulse is 102/min, and respirations are 12/min. Physical exam demonstrates pain on palpation of the right lower quadrant and mild pain in the right upper quadrant. He has significant acne on his face, chest, and back. A CT of the abdomen confirms appendicitis. The scan also shows a large liver mass measuring 6 cm as seen in Figure A. Aside from addressing his appendicitis, which of the following is the most appropriate next step in management?
Administer metronidazole
Administer sofosbuvir
Obtain follow-up CT of the abdomen in 3 months
Perform liver mass resection
Perform liver mass resection
This patient with a history of possible anabolic steroid use (wrestler with acne) who presents with right upper quadrant pain and an enhancing lesion in the liver most likely has a hepatic adenoma. The treatment of hepatic adenomas is surgical removal and discontinuation of precipitating agents.

Hepatic adenomas are benign epithelial tumors that typically arise in the right hepatic lobe. They are typically solitary masses but multiple lesions can be seen in patients with prolonged contraceptive or anabolic steroid use and those who have glycogen storage disorders. Patients present with abdominal pain that is localized in the epigastrium or in the right upper quadrant. Sudden, severe abdominal pain with hypotension suggests rupture of the hepatic adenoma into the peritoneum. The lesions can be confirmed on imaging such as ultrasound, CT, or MRI. For hepatic adenomas that are < 5 cm and asymptomatic, simply discontinuing the causative drug and observing are acceptable. Large or symptomatic lesions requiring surgical resection in addition to discontinuation of the offending agent. Because these tumors are highly vascular, failure to resect may result in rupture, hemoperitoneum, and shock. Biopsy is contraindicated to avoid rupturing the mass and causing hemorrhage.

Klompenhouwer et al. studied the current management strategies in patients with hepatocellular adenoma. They found that various molecular groups have been identified allowing for subtyping of these lesions. They recommend performing a CT scan to better characterize these lesions.

Figure/Illustration A is a CT with an enhancing mass with a hypoattenuating fatty component. This is characteristically seen in large hepatic adenomas, which are solitary well-marginated lesions.

Incorrect Answers:
Answer A: Metronidazole would be an effective treatment if this patient had contracted Entamoeba histolytica from contaminated food or water on his recent trip to Mexico. While this amoeba can lead to a liver abscess presenting as a mass on CT, it often also causes abdominal pain and dysentery due to intestinal involvement.

Answer B: Sofosbuvir is an antiviral medication used for hepatitis C. This patient does have risk factors for hepatitis C (risky sexual behavior and intravenous drug use). Although hepatitis C could lead to hepatocellular carcinoma and cause a liver mass, this patient’s presentation is not consistent with that diagnosis. Even if he did have hepatocellular carcinoma, treating hepatitis C alone without surgical resection or adjuvant therapies would be insufficient.

Answer C: Follow-up CT in 3 months would be dangerous for this man with a large hepatic adenoma. In the interim, the mass will likely continue to grow if he continues to use anabolic steroids, increasing the risk of rupture. Observation and repeat imaging may be suitable for asymptomatic hepatic lesions that are of uncertain but likely benign etiology.

Answer D: Biopsying the liver mass is appropriate if malignancy is suspected and there is no concern for hepatic adenoma. If an adenoma is on the differential, biopsy is contraindicated due to the risk of rupture and hemorrhage intraoperatively.

Bullet Summary:
Hepatic adenomas are benign, vascular liver masses associated with oral contraceptives and anabolic steroids that should be promptly resected if large and symptomatic.