A Case of Adult Undifferentiated Sarcoma of the Liver with Intraatrial Metastasis

A 24-year-old woman was admitted to the hospital for abdominal pain. Abdominal contrast-enhanced computed tomography( CT)revealed a cystic mass measuring 11×8 cm in the left lobe of the liver with extravasation. Vascular embolization was performed, but extravasation remained on CT images. She was then transferred to our hospital. We performed an emergency extended left hepatectomy. Histopathological examination revealed solid proliferation of spindle-shaped cells. Immunohistochemical staining showed that the tumor cells were positive for vimentin and negative for AE1/AE3. Thus, a diagnosis of undifferentiated sarcoma was confirmed. Multiple recurrent tumors were recognized on CT images of the lung and right atrium taken 1 year and 10 months post-surgery. Partial resection of the tumor was performed for the right atrial mass, the left lingular segment, the left inferior lobe, and the right middle lobe. Pathological diagnosis confirmed metastasis of undifferentiated sarcoma from the liver. Chemotherapy consisting of vincristine, actinomycin D, and cyclophosphamide(VAC) was not effective, and the patient died 31 months after the primary surgery. Undifferentiated sarcoma of the liver is a rare malignant mesenchymal tumor, whose occurrence is extremely rare in adults. Although surgical treatment is the first choice, outcomes remain poor. Multimodality treatment should be used to improve the outcome.