Undifferentiated (embryonal) liver sarcoma: synchronous and metachronous occurrence with neoplasms other than mesenchymal liver hamartoma.

Undifferentiated (embryonal) liver sarcoma (UELS) is a rare tumor that typically occurs in children. The association of UELS with neoplasm other than mesenchymal liver hamartoma is exceedingly rare. The aim of the study was to report 3 cases of UELS, 2 of them being interesting because of their association with another neoplasm, vaginal embryonal rhabdomyosarcoma in a teenage girl and B-acute lymphoblastic leukemia in a middle-aged woman. Besides, one of our cases of UELS, in a 58-year-old woman, is an extremely rare presentation of such a tumor in a middle-aged adult. The patient's clinical features, therapy, and pathologic results were reviewed; immunohistochemical analysis and, in 2 cases, electron microscopy were performed. In this study, all 3 patients were females aged 13, 13, and 58 years. Histopathologic evaluation of resected liver tumors confirmed the diagnosis of UELS in all of them. In 2 of the cases, metachronous occurrence of UELS with vaginal embryonal rhabdomyosarcoma in a teenage girl and B-acute lymphoblastic leukemia in a middle-aged woman is described. Careful clinical analysis, histologic studies, and immunohistochemistry are mandatory to distinguish UELS from other hepatic malignancies with similar or overlapping features and to exclude the possibility of other tumors that may be considered in the differential diagnosis. The association of UELS with another neoplasm is exceedingly rare.