Rhabdoid tumor of the liver: Report of 6 pediatric cases treated at a single institute.

Background: Rhabdoid tumors (RTs) of the liver are rare, aggressive and nonsecreting malignancies occurring mainly during the first year of life. Definition of RT relies on characteristic morphology and on the inactivation of the SMARCB1 tumor suppressor gene. The aim of this study was to analyze clinical data, treatments and outcomes in our patients.
Patients and Methods: 6 cases of patients treated in our institution for RT of the liver between January 2007 and January 2015 are reported. Variables examined included age at diagnosis, tumor stage, treatment and long-term survival.
Results: Median age at diagnosis was 5months (range: 4-23). Normal for age serum AFP levels was observed in all patients. No patient presented with metastasis at diagnosis. The diagnosis of RT based on the loss of SMARCB1 was made early in 4 patients. The 2 others were initially diagnosed as nonsecreting hepatoblastomas. Median follow-up was 6years (range: 2-9). All patients received chemotherapy, with variable regimens depending on initial diagnosis, followed by surgical resection. Three patients (50%) died of disease. Two of them were mistaken for nonsecreting hepatoblastomas at diagnosis and had recurrence shortly after completion of treatment. The third one presented a cardiac right atrium thrombus. Three patients (50%) are long-term survivors; they received multimodal therapy including chemotherapy according to protocol EpSSG NRSTS consisting of doxorubicin and surgical removal of the tumor performed within 3months after diagnosis. One patient had adjuvant radiotherapy.
Conclusion: According to our results, search of SMARCB1 mutation or alternatively immunohistochemical assay for SMARCB1 in nonsecreting hepatoblastomas is mandatory to exclude RT. Chemotherapy according to EpSSG NRSTS protocol together with a surgical treatment seems justified to improve long-term survival.
Type of Study: Retrospective study.
Level of Evidence: Level IV.
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