Edited by: Steven Thomas Leach, University of New South Wales, Australia
Reviewed by: Nadeem Omar Kaakoush, University of New South Wales, Australia; Robert Nicholas Lopez, Sydney Children’s Hospital, Australia; Daniel Wai Hung Ho, University of Hong Kong, Hong Kong
Specialty section: This article was submitted to Pediatric Gastroenterology, Hepatology and Nutrition, a section of the journal Frontiers in Pediatrics
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Mucinous cystadenomas (MCAs) of the liver (also called hepatic biliary cystadenomas) are rare tumors that comprise about 5% of cystic masses of the liver in adults. These slow-growing lesions most commonly occur in middle-aged individuals, with a female sex predominance. Herein, we present a MCA in a 6-year-old male, one of only very few such cases described in the pediatric literature to date. Although MCAs are generally considered benign lesions, malignant transformation rarely occurs. The recurrence rate is high when partial cyst excision is performed. Therefore, complete surgical cyst resection with clinical follow-up, including imaging, is warranted.
Mucinous cystadenomas (MCAs) of the liver are rare intrahepatic lesions seldom discovered in childhood. These lesions are typically found incidentally, often during evaluation of non-specific abdominal complaints. Like other more widely described hepatic masses, MCAs can cause symptoms such as abdominal pain, nausea, vomiting, and jaundice from mass effect. These “great pretenders” are easily mistaken for abscesses, cysts, or even malignancy, which prompts diagnostic resections. Characteristically, MCAs are considered benign, although secondary malignant transformation has occurred in as many as 20% of affected adults (
Herein, we report a case of a 6-year-old healthy male diagnosed with MCA after a liver mass was incidentally discovered during an echocardiogram. Through this report, we hope to educate gastroenterologists and surgeons about a rare mass that they may encounter more frequently in practice as abdominal imaging modalities improve. We will discuss the role of imaging and histology in the diagnosis of MCAs, definitive management, and propose a standard for routine surveillance in affected patients.
A 6-year-old previously healthy male presented to the Pediatric Gastroenterology Clinic for evaluation of a liver mass that was incidentally seen on an echocardiogram while assessing a heart murmur. At the time of the discovery of the liver lesion, the patient was asymptomatic, without abdominal pain, anorexia, weight loss, vomiting, jaundice, or other liver-related complaints. Vaccinations, including hepatitis B, were up to date.
Findings on physical examination were normal. Results of serum blood chemistry including markers of liver synthetic function (INR, albumin), transaminases, bilirubin, alpha-fetoprotein (AFP), cancer antigen (CA19-9), and carcinogen embryonic antigen (CEA) were normal. HAV, HBV, and HCV serologies were also negative. An abdominal ultrasound showed a cystic lesion with irregular borders in the left hepatic lobe. The hepatic mass was characterized by computerized tomography (CT) as a circumscribed, complex, multi-lobulated, and septated cystic lesion measuring 5.5 cm × 4.2 cm × 5.2 cm.
Abdominal magnetic resonance imaging (MRI) done 7 months later showed the same complex cystic lesion in the left hepatic lobe without interval change in size. Given the absence of symptoms and benign laboratory and imaging results, we pursued a conservative approach with clinical, biochemical, and radiological follow-up every 6 months. Results of the patient’s laboratory tests remained normal, but the lesion showed slight growth on ultrasound over the following 2.5 years. A repeat abdominal MRI (with Eovist contrast) showed the complex multi-cystic lesion had increased slightly in size to 6.1 cm × 4.1 cm × 6.4 cm (Figure
Due to the enlargement and complex nature of the lesion, the patient was referred to our hepatobiliary surgeons for resection. Exploratory laparotomy showed normal exterior hepatic tissue but a mass was palpable beneath the left hepatic lobe. A hepatic laparoscopic ultrasound showed that the tumor supplanted the parenchyma of the lateral segment of the liver. As a result, a left lateral hepatectomy was performed with complete excision of the mass. The patient tolerated the procedure well and was discharged home on postoperative day 3.
Gross histopathological assessment revealed a well-circumscribed 7.3 cm × 5.8 cm mass (Figure
Our patient returned to clinic every 6 months for routine physical exam, laboratory work, and ultrasound of the liver. Seventeen months after the tumor resection, the patient remained asymptomatic. MRI of the abdomen was performed at 19 months, which showed only expected postsurgical changes and no recurrence of the mass. His tumor markers, including AFP, CEA, and CA 19-9 remained within normal limits, as did markers of synthetic function. He continues to have regular follow-up at 6-month intervals.
Hepatic MCAs are benign tumors that are often discovered incidentally on imaging. These hepatic tumors make up approximately 5% of cystic hepatic lesions of the liver in the adult population (
Mucinous cystadenomas have an insidious nature and are often asymptomatic or present with vague symptoms. Large tumors can give rise to symptoms related to mass effect, including abdominal pain and clinical signs of biliary obstruction. The most common findings at diagnosis are abdominal pain (60–90%), palpable abdominal mass (up to 53%), nausea, vomiting and rarely, jaundice (
On imaging, lesions may be unilocular or multilocular and resemble abscesses, echinococcal cysts, teratomas, hematomas, necrotic tumors, and polycystic disease (
Histologically, MCAs are usually lined with cuboidal or non-ciliated columnar cells, with basal nuclei and mucin-containing cytoplasm (
Because it is difficult to diagnose MCAs by imaging, the gold standard for treating these lesions is complete surgical resection with confirmed clear margins (
Percutaneous biopsy and analysis of cystic contents have been proposed as a less invasive diagnostic option (
In summary, given the lack of consistently reliable non-invasive diagnostic methods and high tumor recurrence rate with partial resection, complete surgical excision is considered the gold standard. Even with complete removal, the recurrence rate is 5–10% in adults (
Written informed consent for the presentation and publication of this case was obtained from the patient’s legal guardian.
DF and MM drafted the manuscript. IZ edited the manuscript, and obtained and interpreted the gross pathology images. DH-G edited the manuscript and obtained and interpreted the microscopic pathology images. RG-P critically reviewed the manuscript and is the author guarantor.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer NK and handling editor declared their shared affiliation.