�������

A 28-year-old female with a history of laparoscopic cholecystectomy one year ago presents to the GI clinic for follow-up of a possible “cyst on her liver.” At the time of her cholecystectomy, an ultrasound of the gallbladder and biliary tree was performed. She recalls her surgeon recommending follow-up with a gastroenterologist for further evaluation. She is asymptomatic. Recent labs by her primary physician include a normal complete blood count and comprehensive metabolic panel. She has no known personal or family history of liver disease. She denies risk factors for viral hepatitis. She consumes four to six alcoholic beverages per week. She has hypothyroid disease that is well controlled on once daily levothyroxine. She does not take any other medications, vitamins or herbal supplements.

The preferred initial imaging study to assess for hepatic cysts is:

A. Upright and supine abdominal films
B) Transabdominal ultrasound of the liver
C) Triple phase hepatic CT
D) MRI of the liver with dynamic contrast

The correct answer is B, transabdominal ultrasound of the liver.

Practice Pearls

Prevalence and Natural History of Simple Liver Cysts

• Simple hepatic cysts are true cysts, typically found incidentally on imaging studies.^1,2 They have an outer layer of fibrous tissue and are lined with columnar epithelium that produces fluid.
• The true prevalence of simple hepatic cysts is unclear. Early laparotomy series reported a prevalence of 0.2 percent to 1 percent.² Ultrasound (U/S) series report a 3 percent to 5 percent prevalence and CT series report a prevalence as high as 15 percent to 18 percent.²
• With the increased use of abdominal imaging studies, hepatic cysts are an increasingly common finding.
• The natural history has not been clearly outlined; however, simple hepatic cysts are not thought to be premalignant and generally have a benign course.^1,2
• Simple cysts are more common in the right lobe of the liver and more prevalent in females.¹ Large cysts are found almost exclusively in females over age 50.¹

Hepatic Imaging Studies

U/S:

• Ultrasonography is the most helpful first test. This can differentiate a simple cyst from other cystic lesions.¹
• U/S is safe and low cost.²
• Simple cysts (Image 1) appear as an anechoic unilocular fluid-filled space with imperceptible walls and with posterior acoustic enhancement.¹
• A hepatic cyst identified on U/S with septations, fenestrations, calcifications, irregular walls or daughter cysts should prompt further evaluation with a CT or MRI.²

CT:

• A simple cyst seen on CT (Image 2) is defined as a well-demarcated water-attenuation lesion that does not enhance following administration of IV contrast.¹
• Uncomplicated cysts are virtually never septated.¹
• The most important aspect for CT imaging is the need for a late arterial phase, a portal venous phase and a delayed venous phase. This is referred to as a “triple-phase” study, which is distinct from a standard abdominal CT that includes only a portal venous phase and a delayed phase.²
• CT abdomen with IV contrast triple-phase (or multiphase) is usually appropriate for an indeterminate greater than 1 cm liver lesion on initial imaging with U/S in a patient without suspicion or evidence of extrahepatic malignancy or underlying disease.³

MRI:

• MRI demonstrates a well-defined water-signal lesion that does not enhance following the administration of IV gadolinium.¹
• Cysts that have internal septations, fenestrations, calcifications, irregular walls or daughter cysts on U/S should be evaluated with CT or MRI for features of BCA or hydatid cysts.²
• MRI of the abdomen without and with IV contrast is usually appropriate for an indeterminate greater than 1-cm liver lesion on initial imaging with U/S in a patient without suspicion or evidence of extrahepatic malignancy or underlying disease.³

Management of Simple Hepatic Cysts

• No intervention or follow-up imaging for cyst surveillance is needed for asymptomatic patients with a simple hepatic cyst.^1,2
• Patients with large (≥4 cm), symptomatic simple hepatic cysts may require intervention.¹ It is important to rule out other sources of abdominal pain prior to accepting the cysts as the source of pain.
• There are no randomized trials comparing interventions.¹ Common approaches include needle aspiration with injection of a sclerosing agent and laparoscopic cyst deroofing.
• Laparoscopic cyst deroofing is safe.Recurrence rates range from 0 percent to 14 percent, with morbidity rates of 0 percent to 15 percent.¹
• Percutaneous needle aspiration of the cyst with sclerotherapy is a reasonable, less invasive alternative to surgery for patients who require intervention and decline surgery or are not surgical candidates.¹ Based on limited data, recurrence rates are high and major complications are low.
• Percutaneous cyst aspiration without sclerotherapy is not typically used for symptomatic cysts because the fluid usually reaccumulates inside the cyst cavity.¹

Image 1: U/S showing hepatic cyst

Image 2: CT Abdomen showing hepatic cyst

All images from the personal library of Robert A. Murray, MD.

• Authors
• References

Sarah Enslin, PA-C

University of Rochester Medical Center

Rochester, NY

Robert A. Murray, MD

OSF St. Anthony Medical Center

Rockford, IL

Sarah Stainko, MSN, NP-C

Indiana University Health

Indianapolis, IN

Joseph Vicari, MD, MBA, F�������

Rockford Gastroenterology Associates

Rockford, IL

Sarah Enslin, PA-C, is a physician assistant in the division of gastroenterology and hepatology at the University of Rochester Medical Center in Rochester, NY, with over 10 years of experience as a practicing PA in GI. Sarah serves on several national GI committees and is a member of the ������� Practice Operations Committee and ������� APP Task Force.

Robert A. Murray, MD, is a staff neuroradiologist at OSF St. Anthony Medical Center in Rockford, IL. Additionally, he is a clinical assistant professor at the University of Illinois at Chicago, College of Medicine, at Rockford and adjunct professor in the department of physician assistant studies at Marquette University in Milwaukee, WI.

Sarah Stainko, MSN, NP-C is a board-certified nurse practitioner in the division of gastroenterology and hepatology at Indiana University Health in Indianapolis, IN. She works in the area of destination services, innovative endoscopy and motility.

Joseph Vicari, MD, F�������, joined Rockford Gastroenterology in 1997 and has served as managing partner. He previously served as chair of the ������� Practice Operations Committee and currently serves as councilor on the ������� Governing Board and co-chair of the ������� APP Task Force.

1. Regev A, Reddy R. Diagnosis and management of cystic lesions of the liver. Updated August 29, 2022. UpToDate. .
2. Marrero J, Ahn J, Reddy R. ACG clinical guideline: the diagnosis and management of focal liver lesions. Am J Gastroenterol. 2014;109:1328-1347.
3. Expert Panel on Gastrointestinal Imaging; Chernyak V, Horowitz JM, Kamel IR, et al. ACR Appropriateness Criteria® Liver Lesion-Initial Characterization. J Am Coll Radiol. 2020;17:S429-S446. doi: 10.1016/j.jacr.2020.09.005. PMID: 33153555.