A single-institution retrospective cases series of childhood undifferentiated embryonal liver sarcoma (UELS): success of combined therapy and the use of orthotopic liver transplant.

BACKGROUND/INTRODUCTION: Undifferentiated embryonal liver sarcoma (UELS) makes up 9% to 15% of all malignant liver tumors in children. UELS is characteristically diagnosed between the ages of 6 and 10 years and presents with abdominal pain, vomiting, and an abdominal mass. There is currently no standardized treatment for UELS except attempt at complete surgical resection. There have been only about 150 cases of UELS reported in the literature all with historically poor overall survival of <37.5% at 5 years. This report is one of the largest single-institution reports of UELS consisting of 5 patients over 2 decades. The purpose of this study is to characterize presentation and to report treatment success in UELS in children, adolescents, and young adults and the use of liver transplantation and, lastly, to suggest a use of positron emission tomography/computed tomography (PET/CT) in monitoring of this disease process.

METHODS: We conducted an Institutional Review Board-approved retrospective chart review. Data were collected from UELS patients younger than 21 years seen at the University of California Los Angeles over the past 20 years (January 2001 to September 2011). Descriptive analysis was conducted including multiple parameters of patient demographics, tumor characteristics, treatment modalities, and morbidity and mortality.

RESULTS: Five patients with UELS were identified. Patients initially presented with fever, abdominal pain, or nausea. Ages ranged from 10 to 19 years old (median age 13 y old), and there was a 4:1 male-to-female predominance. Tumor size ranged from 6 to 22 cm in largest diameter. One patient presented with metastatic disease to the lungs and heart and 1 patient recurred 2 years from diagnosis with bilateral paraspinal masses. Treatment included local control surgery with neoadjuvant and adjuvant chemotherapy with an anthracycline/alkylating agent combination. One patient with recurrent and refractory disease achieved local control with an orthotopic liver transplantation (OLT). Metastatic disease was controlled with surgery and radiation therapy. 18-Fluorodeoxyglucose PET/CT was a useful imaging tool for judging response to therapy with complete loss of metabolic activity in tumor after neoadjuvant chemotherapy in 2 representative cases. Although follow-up is short for some patients, overall survival in these 5 patients was 100% with follow-up ranging from 21 to 68 months. Disease-free survival ranged from 8 to 46 months with no patients with residual disease.

CONCLUSIONS: UELS is an aggressive high-grade primary liver sarcoma with high metastatic potential. This report represents one of the largest single-institution studies of UELS. Using multimodality therapy, patients have achieved 100% overall survival even in the setting of extensive disease, metastases, and recurrence. In cases of unresectable primary tumor or recurrent and refractory disease isolated to the liver, OLT is a potential therapeutic option. We report success with adjuvant chemotherapy and complete surgical resection with OLT as an alternative in unresectable or refractory cases. We also suggest a possible utility of PET/CT in monitoring treatment response in this disease.