Image of the Month—Diagnosis FREE

Figure 1. Computed tomographic scan of the abdomen demonstrating a large enhancing mass in the right hemiliver.

Figure 2. Intraoperative photograph demonstrating the nodular surface of the mass protruding from the undersurface of the right hemiliver. Scale in centimeters is shown.

The preoperative evaluation of primary hepatic tumors in children can be challenging. In young patients aged 5 to 20 years, malignant tumors outnumber benign tumors by an approximately 2:1 ratio.¹Focal nodular hyperplasia (FNH) is a benign lesion with a distinct female predominance, and it is commonly seen in adults and less commonly in children. More than 90% of the lesions are asymptomatic. Review of the literature suggests that the average size of pediatric FNH lesions that come to clinical attention is 7.5 cm, although a large range of tumor sizes has been reported.^2- 4The cause of FNH remains unclear, although vascular anomaly or injury has been theorized. In addition, oral contraceptive use may be associated with a higher rate of bleeding into FNH lesions.¹Although treatment of FNH has often consisted of surgical resection, observation alone has also been associated with a good outcome.³However, resection is advocated in symptomatic cases or in any cases of diagnostic uncertainty.

Hepatoblastoma is the most frequent primary hepatic malignancy in children from birth to 2 years of age, and most hepatoblastoma lesions are seen before the child is 5 years old.¹Typical manifestation is an abdominal mass, often identified by parents or at routine examination. Symptoms, when they occur, include weight loss, anorexia, nausea, abdominal pain, and jaundice; α-fetoprotein levels are elevated in more than 90% of cases and can be used to aid diagnosis, as well as to follow response to therapy or resection.^1,5Although half of hepatoblastoma lesions are considered unresectable at the time of diagnosis, and as many as 20% of patients may have pulmonary metastases, neoadjuvant chemotherapy can increase the resectability rate to 90%, although extensive resection and even liver transplantation may be required for larger lesions.⁶

Hepatocellular carcinoma is the most frequent primary hepatic maliganancy in patients aged 5 to 20 years, with abdominal pain and/or an abdominal mass being the most common manifestation.¹A higher prevalence of hepatocellular carcinoma has been described in both adults and children with hepatitis B virus seropositivity, with vertical transmission being an important route of exposure in the pediatric group.⁷Laboratory findings may include elevated levels of α-fetoprotein, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase. Computed tomography or magnetic resonance imaging are most useful for determining resectability, which is possible in only 10% to 30% of cases.⁸Although surgical resection, including liver transplantation when appropriate, along with chemotherapy and irradiation, are the mainstay of treatment, the long-term prognosis is poor.

Undifferentiated embryonal sarcoma is an unusual primary hepatic tumor that is most commonly seen in children. Patients usually have abdominal pain and/or an abdominal mass, often associated with anorexia, nausea, vomiting, and less often associated with chest pain, jaundice, fever, and cardiac murmur secondary to extension of tumor. Undifferentiated embryonal sarcoma tumors are typically large, with lesions as big as 35 cm in diameter.¹Although undifferentiated embryonal sarcoma may be associated with elevated levels of aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase, an elevated level of α-fetoprotein is not seen with this tumor. At computed tomography or magnetic resonance imaging, undifferentiated embryonal sarcoma may appear cystlike, although findings at ultrasonography and pathology analysis can be used to confirm the predominantly solid nature of these tumors.^8- 9As with hepatocellular carcinoma, surgical resection and various combinations of chemotherapy and radiation have been used to treat undifferentiated embryonal sarcoma, but long-term outcome remains poor.

Corresponding author: Jeffrey A. Lowell, MD, Department of Surgery, Washington University School of Medicine, 660 S Euclid Ave, Campus Box 8109, St Louis, MO 63110 (e-mail: lowellj@wustl.edu).

Submissions Due to the overwhelmingly positive response to the "Image of the Month," the Archives of Surgery has temporarily discontinued accepting submissions for this feature. It is anticipated that requests for submissions will resume in mid 2004. Thank you.