Undifferentiated (Embryonal) Sarcoma of the Liver in Childhood: Results of a Retrospective Italian Study

Embryonal sarcoma of the liver in pediatric and young adult patients: A report from Children's Oncology Group study ARST0332

BACKGROUND

Embryonal sarcoma of the liver (ESL) is a rare mesenchymal tumor most common in childhood; the optimal treatment approach is uncertain. The clinical features and outcomes of patients with ESL enrolled in a Children's Oncology Group (COG) clinical trial that evaluated a risk-based strategy for treating soft tissue sarcomas in patients aged <30 years were evaluated.

METHODS

This subset analysis included patients with ESL enrolled in COG study ARST0332. Central review of records, pathology, and imaging confirmed the diagnosis, presenting features, and surgery extent and complications. All patients received dose-intensive ifosfamide/doxorubicin chemotherapy, with cycle timing dependent on surgery and radiotherapy. Tumor resection occurred before study entry or after four cycles of chemotherapy; radiotherapy for residual tumor was optional.

RESULTS

Thirty-nine eligible/evaluable patients with ESL were analyzed. All tumors were >10 cm in diameter; four were metastatic. Tumor resection was performed upfront in 23 and delayed in 16. Positive surgical margins (n = 6) and intraoperative tumor rupture (n = 6) occurred only in upfront resections. Eight patients received radiotherapy. Estimated 5-year event-free and overall survival were 79% (95% confidence interval [CI], 65%-93%) and 95% (95% CI, 87%-100%), respectively. Positive margins increased the local recurrence risk. One of 13 patients with documented hemorrhagic ascites and/or tumor rupture developed extrahepatic intra-abdominal tumor recurrence.

CONCLUSIONS

The treatment strategy used in ARST0332 achieved favorable outcomes for patients with ESL despite a substantial proportion having high-risk disease features. Deferring tumor resection until after neoadjuvant chemotherapy may decrease the risk of intraoperative tumor rupture and improve the likelihood of adequate surgical margins.

Case report: Undifferentiated sarcoma with multiple tumors involved in Lynch syndrome: Unexpected favorable outcome to sintilimab combined with chemotherapy

Background

Patients with Lynch syndrome are at an increased risk of developing simultaneous or metachronous tumors, while sarcomas have been occasionally reported. Sarcomas are generally not considered part of the common Lynch syndrome tumor spectrum. However, more and more studies and case reports suggested that sarcoma could be a rare clinical manifestation of Lynch syndrome, leading to new treatment strategies for sarcoma.

Case summary

We report the case of a 74-year-old male patient with Lynch syndrome who had rectal mucinous adenocarcinoma and prostate adenocarcinoma and then developed undifferentiated sarcoma of the left neck two years later. Mismatch repair deficiency (dMMR) was confirmed by immunohistochemical staining for the mismatch repair proteins MSH2, MSH6, MLH1 and PMS2. The result of polymerase chain reaction (PCR) microsatellite instability (MSI) testing of sarcoma showed high-level microsatellite instability (MSI-H). Additionally, a pathogenic germline mutation in MSH2 (c.2459-12A&gt;G) was detected by next-generation sequencing (NGS). Taking into account HE morphology, immunohistochemical phenotype, MSI status, NGS result, medical history and germline MSH2 gene mutation, the pathological diagnosis of left neck biopsy tissue was Lynch syndrome related undifferentiated sarcoma with epithelioid morphology. The patient has been receiving immunotherapy (sintilimab) combined with chemotherapy (tegafur, gimeracil and oteracil potassium capsules) and currently has stable disease. We also reviewed the literature to understand the association between sarcoma and Lynch syndrome.

Conclusion

Sarcoma may now be considered a rare clinical manifestation of Lynch syndrome. Attention and awareness about the association between Lynch syndrome and sarcoma need to be increased. Therefore, timely detection of MMR proteins and validation at the gene level for suspicious patients are the keys to avoiding missed or delayed diagnosis and to identifying patients suited for immunotherapy, which may also help to provide appropriate genetic counseling and follow-up management for patients.

A case of adult undifferentiated embryonal sarcoma of the liver successfully treated with right trisectionectomy: a case report

Background

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant mesenchymal tumor that usually occurs in children and is rarely diagnosed in adults.

Case presentation

Here, we describe the case of a 65-year-old woman who presented with a huge cystic lesion in the liver. Laboratory studies performed on admission showed modest inflammation, poor nutrition, and elevated levels of total bilirubin, alkaline phosphatase, and γ-glutamyl transferase. Computed tomography showed a well-defined, heterogeneous tumor with multiple cysts involving the right lobe and the medial segment of the liver, with a maximum diameter of 16 cm. Positron emission tomography/computed tomographic scans showed the uptake of 2-(fluorine-18)-fluoro-2-deoxy-d-glucose in a part of the cyst. The patient was diagnosed with mucinous cystadenocarcinoma or sarcoma of the liver and underwent right trisectionectomy. Histopathological studies revealed that the tumor was composed of pleomorphic and polynuclear dyskaryotic cells with eosinophilic globules in the cytoplasm. Mesenchymal hamartoma-like tissue was observed in the peripheral part of the tumor. Immunohistochemical analyses showed the tumor stained with vimentin, α-smooth muscle actin, desmin, α1-antitrypsin, and α1-antichymotripsin. Therefore, a histological diagnosis of UESL was made. Eighteen months following treatment, two recurrent tumors in the remnant liver were detected and resection of the recurrent tumors was performed.

Conclusions

A UESL should be considered in the differential diagnosis of large cystic hepatic lesions. Although the prognosis of UESL is extremely unfavorable, aggressive surgical resection should be the most important factor for ensuring long-term survival.

Undifferentiated Embryonal Sarcoma of the Liver (UESL): A Single-Center Experience and Review of the Literature

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare and aggressive pediatric malignancy. The purpose of this study was to review the clinical, radiologic, and pathologic features and outcome of children with UESL at our institution, in the United Network of Organ Sharing database and to review the existing literature to define the state of the art for children with UESL. Six children were diagnosed with UESL at the Texas Children's Cancer Center between 1993 and 2014, 12 children underwent liver transplantation registered in the United Network of Organ Sharing database, and 198 children with UESL were described in 23 case series during 1978 to 2014. Patients were treated with multimodal treatment approaches including primary surgical resection, neoadjuvant and/or adjuvant chemotherapy, and liver transplantation resulting in overall survival reported between 20% and 100% with significant improvement over the recent years. We show that complete tumor removal remains the key element of treatment and our single-institutional experience and data in the published literature suggest that combination chemotherapy with ifosfamide and doxorubicin to facilitate complete surgical resection is an effective approach to cure children with UESL.

Spontaneous hepatic haemorrhage: a review of pathogenesis, aetiology and treatment

BACKGROUND

A spontaneous hepatic haemorrhage (SHH) is a rare condition that presents acutely to both hepatobiliary and general surgeons. Management of the condition is challenging because of the emergent presentation requiring immediate intervention, the presence of underlying chronic liver disease and the multiple potential underlying aetiological conditions.

METHODS

A literature search on a spontaneous hepatic haemorrhage was instituted on Medline (1966-2014), Cochrane Register of Controlled Trials, EMBASE (1947-2014), PubMed, Web of Science and Google Scholar. The specific topics of interest were causes - including rare causes, pathophysiological mechanisms and management options. A narrative review was planned from the outset.

RESULTS

After 1546 abstracts were reviewed, 74 studies were chosen for inclusion. Hepatocellular carcinoma (HCC) is the commonest cause of a spontaneous haemorrhage with 10% of HCC presenting with bleeding. Other causes are benign hepatic lesions (hemangioma, adenoma, focal nodular hyperplasia, nodular regenerative hyperplasia, biliary cystadenoma and angiomyelolipoma), malignant hepatic tumours (angiosarcoma, haemangioendothelioma, hepatoblastoma and rhabdoid sarcoma), peliosis hepatis, amyloid, systemic lupus erythematosis, polyarteritis nodosa, HELLP syndrome and acute fatty liver of pregnancy. Treatment practice emphasizes arterial embolization to obtain haemostasis with a hepatectomy reserved for tumour-bearing patients after staging and assessment of liver function.

CONCLUSION

A spontaneous hepatic haemorrhage is an acute presentation of a spectrum of conditions that requires early diagnosis and multidisciplinary management.

Embryonal sarcoma of the liver

PURPOSE

Embryonal sarcoma accounts for 6 % of liver tumors. This study reviews its features and the results of treatment in a referral center.

METHODS

We retrospectively reviewed liver tumors treated between 1995 and 2011. PRETEXT staging and biopsy were used to tailor chemotherapy according to SIOP protocols. Radical surgery was performed when possible. Complications and cumulative survival were the outcome endpoints.

RESULTS

Six out of 156 primary liver tumors (four males and two females) were sarcomas. The mean age at diagnosis was 81 ± 8.5 months. The most frequent finding was abdominal mass. Alfa-fetoprotein was normal. Imaging depicted heterogeneous tumors with septa, necrosis, and hemorrhagic areas. The diagnosis was ascertained by biopsy. Three tumors were located in the right lobe (PRETEXT II): two were bilobar (PRETEXT III) and one was in the left lobe (PRETEXT I). Two children had metastases at diagnosis and high-risk chemotherapy (vincristine, carboplatin, epirubicin) was administered with poor response. They died without operation 4 and 10 months later. Four patients with local disease underwent typical liver resections after chemotherapy (iphosphamide, vincristine, actinomycin D, and doxorrubicin). Overall actuarial survival at 70 months was 66.6 %.

CONCLUSIONS

Extended and metastatic embryonal sarcoma do poorly whereas localized tumors amenable to complete surgical removal after chemotherapy can cure.

Rare case of adult undifferentiated (embryonal) sarcoma of the liver treated with liver transplantation: excellent long-term survival

We present the case of a 54-year-old gentleman who presented with abdominal distension and a CT scan of his abdomen revealed a large (25 cm) left hepatic lobe tumor. He received chemotherapy for over 1.5 years. The CT scans at the completion of this therapy revealed that the tumor had actually slightly grown in size. He underwent orthotopic liver transplantation without any major complications. The explant histopathology revealed an undifferentiated embryonal cell sarcoma (UECS) composed of relatively bland spindled cells arranged in short fascicles. It is now 10 years and 3 months since his last transplant and the patient remains well with no tumor recurrence.

Undifferentiated sarcoma of the liver: a rare pediatric tumor

Undifferentiated embryonal sarcoma of the liver (UESL) is an uncommon hepatic tumor of mesenchymal origin recognized as a unique clinicopathologic entity since 1978. UESL has historically been considered an aggressive neoplasm with an unfavorable prognosis. Survival has improved using recent multimodal approaches, designed for patients with soft tissue sarcomas at other sites. Several small series have reported survival of up to 70% of children. We report a case of a 12-year-old boy from the United Arab Emirates who relapsed after complete surgical resection and was then successfully treated with re-resection followed by chemotherapy and radiotherapy. With a follow-up of 5 years, he is well and asymptomatic, and is leading a healthy life. This case emphasizes the fact that these poorly prognostic tumors may benefit from post-surgery chemotherapy. This case illustrates the improved survival of UESL patients following the multimodality therapy with a relatively long follow-up. This is the first case of UESL reported in this region of the world.

Childhood undifferentiated embryonal liver sarcoma: clinical features and immunohistochemistry analysis

PURPOSE

The aim of the study was to report on 3 cases of childhood undifferentiated embryonal liver sarcoma (UELS) and to highlight the clinical features, laboratory findings, diagnosis, and management of this rare disease.

METHODS

The patients' age, sex, clinical features, laboratory findings, pathologic results, and therapy were reviewed. Immunohistochemistry analysis was performed on the resected mass sections.

RESULTS

In this study, 2 cases were female (aged 8 and 12 years) and 1 was male (aged 9 years). The causes of hospitalization were mainly abdominal pain, mass, or fever. An elevated erythrocyte sedimentation rate was noted in 2 available cases, and alpha fetoprotein (AFP) was within the normal range. Imaging findings indicated a well-defined heterogeneous large mass in the right lobe. Histopathologic evaluation of the mass confirmed the diagnosis of UELS. Immunohistochemical staining showed that vimentin and CD68 antigen were positive in all samples, whereas desmin was positive in one sample. Surgery with chemotherapy was performed in 2 cases.

CONCLUSION

The diagnosis of UELS depends mainly on the pathologic findings. Undifferentiated embryonal liver sarcoma should be included in the differential diagnosis of mass in the liver, especially with well-defined heterogeneous imaging findings and normal AFP. Diagnosis and management should be made early as UELS is a potentially treatable tumor.

[Hepatic undifferentiated (embryonal) sarcoma in an adult: a case report and literature review]

Undifferentiated (embryonal) sarcoma of the liver (USL) is a rare malignant hepatic tumor in adults. We report the case of a 40-year-old man with USL who was successfully treated with surgical resection and chemotherapy using ifosfamide and adriamycin. To our knowledge, only 70 cases of USL in adults have been reported worldwide in the 40 years since this clinicopathological entity was defined. Although the prognosis of the disease remains generally poor, long term survival has been achieved in patients with a combination of surgery and chemotherapy.

Immunohistochemical analysis of embryonal sarcoma of the liver

Embryonal sarcoma of the liver is a rare, aggressive malignant tumor that typically occurs in children and teenagers. Microscopic features include spindle, oval, or stellate cells with poorly defined cell borders, nuclear pleomorphism and multinucleation, and variable immunoreactivity to cytokeratin, vimentin, and alpha-1-antitrypsin. Intracellular and extracellular PAS-positive, diastase-resistant hyaline globules are commonly present. The authors evaluated a panel of IHC stains to better define the pattern of immunoreactivity in this tumor. Embryonal sarcomas of the liver were identified from archival files and were immunostained with antibodies: cytokeratin AE1/3, hepatocyte, SMMS, myogenin, calponin, h-caldesmon, desmin, S100, vimentin, CD34, C-kit (CD117), CD10, ALK-1, PE10, Bcl2, p53, and Ki-67. Six cases were identified. Patient age ranged from 6 to 24 years. Tumors ranged from 10 to 20 cm and contained spindled and epithelioid areas with PAS-positive, diastase-resistant globules and atypical cells with focal multinucleation. All cases showed immunoreactivity with vimentin and five showed immunoreactivity with Bcl2. Focal immunoreactivity was seen with cytokeratin AE1/3 in three cases, CD10 in four, calponin in two, desmin in one, and p53 in four. All tumors were negative with hepatocyte, myogenin, CD34, SMMS, h-caldesmon, PE10, ALK-1, and S100. No cytoplasmic staining was seen with C-kit. The proliferation index ranged from 30% to 95%. The diagnosis of embryonal sarcoma is based on typical morphologic features in a large liver tumor occurring in a young patient. The most useful IHC stains help to exclude tumors such as hepatoblastoma, hepatocellular carcinoma, embryonal rhabdomyosarcoma, and other sarcomas.

Undifferentiated sarcoma of the liver in childhood: a curable disease

BACKGROUND

Undifferentiated (embryonal) sarcoma of the liver (UESL) is a rare childhood hepatic tumor, and it is generally considered an aggressive neoplasm with an unfavorable prognosis.

METHODS

The Soft Tissue Sarcoma Italian and German Cooperative Groups enrolled 17 children with UESL in studies conducted between 1979 and 1995. They were treated using the same multimodal approach as for patients with sarcomas including conservative surgery at diagnosis, multiagent chemotherapy, and second-look operation in cases of residual disease. Radiotherapy was occasionally used (2 of 17 patients).

RESULTS

Twelve patients are alive with follow-up ranging from 2.4 to 20 years. Eight underwent complete tumor resection either at diagnosis or after preoperative chemotherapy, and all are currently alive. After initial chemotherapy tumor reduction was evident in six of nine evaluable cases. Overall three patients died of disease and one of a surgical complication. One child died in second complete remission for a non-disease-related cause.

CONCLUSIONS

The current prognosis of UESL no longer should be regarded as poor. Modern multimodal treatment and supportive therapy have improved survival.

Mesenchymal tumors of the liver

Primary angiosarcoma of the liver accounts for up to 2% of all primary liver tumors and is the second most common primary malignant neoplasm of the liver. Approximately 10 to 20 new cases are diagnosed every year in the United States and the prevalence varies from 0.14 to 0.25 per million. In an autopsy series from Chicago, one hepatic angiosarcoma was noted for every 30 cases of hepatocellular carcinoma.

Undifferentiated (embryonal) sarcoma of the liver: fine-needle aspiration cytology and preoperative chemotherapy as an approach to diagnosis and initial treatment. A case report

The present report describes the case of a 9-year-old girl with an undifferentiated (embryonal) sarcoma of the liver diagnosed by fine-needle aspiration cytology (FNAC). The smears revealed pleomorphic cells, some with cytoplasmic vacuoles and eosinophilic inclusions, as well as spindle cells and myxoid tissue, cytologic features which appear to be distinctive from any other malignant tumor of the liver. Preoperative chemotherapy was then given using a protocol for high-grade soft-tissue sarcomas (MMT95 953 branch B, SIOP). This scheme induced very good response allowing complete surgery 8 months after diagnosis. The patient is alive and well 11 months after surgery. The combined FNAC-preoperative chemotherapy approach may prove useful for this highly malignant tumor.

Primary multilocular cystic undifferentiated (embryonal) sarcoma of the liver in childhood resembling hydatid cyst of the liver

Undifferentiated (embryonal) sarcoma (UES) is a very rare primary malignant tumour of the liver; typically presenting in later childhood. This tumour usually appears on CT and ultrasound as a predominantly solid mass with or without cystic areas. We report a case of primary UES which had a multilocular cystic appearance resembling a hydatid cyst on imaging.

Cytopathology of undifferentiated (embryonal) sarcoma of the liver

We have studied one undifferentiated (embryonal) sarcoma of the liver (USL) by fine-needle aspiration cytology (FNAC) and have correlated the cytologic findings with those seen in the histologic sections. The main cytologic and immunocytochemical features were: cellular aspirates, mesenchymal clusters, disparity in individual cell size (small round cells, and multinucleated giant cells, sometimes bizarre), absence of biliary pigment, AFP-negative and vimentin-negative tumor cells, AFP-negative and PAS-positive hyaline globules, and apoptotic cells. Only immunostaining for alpha-1-antitrypsin, alpha-1-antichymotrypsin, and carcinoembryonic antigen were positive in tumor cells in histologic sections. The differential diagnosis should be carried out with rhabdomyosarcomas, hepatoblastomas, malignant fibrous histiocytomas, and poorly differentiated hepatocarcinomas. We think that the cytologic features observed in this case, evaluated both in the appropriate clinical context and in the light of the laboratory findings, may permit the correct diagnosis of this infrequent liver tumor. Nevertheless, more cases need to be studied to assess the reliability of our findings.

Undifferentiated embryonal sarcoma of the liver treated with chemotherapy: CT imaging in four patients

BACKGROUND

The purpose of this study was to describe the computed tomography (CT) findings of undifferentiated embryonal sarcoma after chemotherapy and to correlate the CT imaging findings with pathologic findings.

METHODS

Ten CT images obtained before and after chemotherapy in four patients with hepatic undifferentiated embryonal sarcoma were retrospectively reviewed and correlated with pathologic findings.

RESULTS

After chemotherapy, tumor volume decreased by 50-90% and initially nonresectable tumor or gross residual tumor was successfully excised in three patients. In all patients, enhancing peripheral solid portions and septations changed to low-attenuation areas, and in three patients increased or de novo calcifications were found at the periphery of the tumor. Resected pathologic specimen after chemotherapy showed well-encapsulated masses with central necrosis, fibrosis, and dystrophic calcifications.

CONCLUSIONS

These CT findings will be useful in monitoring the treatment response of hepatic undifferentiated embryonal sarcoma during chemotherapy.

Primitive malignant nonepithelial hepatic tumors in children

Primary intrahepatic malignant nonepithelial tumors are very rare in children and account for 2% of all malignant mesenchymatous tumors under the age of 15 years. Clinical presentation, radiologic features, and histologic types are not unequivocal. The predominant role of surgery takes place either initially in small localized tumors or later, after initial reductive chemotherapy. In all cases, complete resection is the necessary but not sufficient condition for cure. Additional radiotherapy seems ineffective. High-dose chemotherapy and/or liver transplantation can be proposed for resistant cases. The disease-free survival rate is 37% at 2 years for the whole series.

The hepatic malignant mesenchymoma: a case report

We report a case of hepatic mesenchymoma in an 8-year-old girl who presented with abdominal pain and ultrasonographic diagnosis of hepatic echinococcosis. Due to the good general condition of the patient and the diagnostic confirmation of liver hydatid disease by the CT scan, antiparasitic therapy with albendazole was started. After 1 month of therapy the girl's general condition worsened as did the ultrasonographic picture. On laparatomy a large cystic mass was observed within the right hepatic lobe and was removed. Pathological examination of the mass excluded an echinococcal cyst and demonstrated a malignant hepatic mesenchymoma.

Undifferentiated (embryonal) sarcoma of the liver. Pathologic findings and long-term survival after complete surgical resection

Undifferentiated (embryonal) sarcoma of liver is a rare tumor with a reputed poor prognosis. Four patients with this tumor are reported, of whom three were alive without recurrence 1.5, 2.5, and 12 years after initial complete surgical resection, and two of whom received no adjuvant therapy. The fourth patient, in whom complete surgical resection of tumor was not achieved, died with recurrent tumor at 13 months. The latter tumor differed histologically and consisted mainly of closely packed smaller undifferentiated cells with a higher mitotic and apoptotic rate. Eosinophilic globules, characteristic of embryonal sarcoma, were found in some cases to contain condensed nuclear chromatin, evidence of origin from tumor cells dying by apoptosis. One tumor mainly contained large cysts lined by biliary-type epithelium; this suggested an origin from a multipotent precursor cell able to differentiate along both stromal and epithelial lines.

Undifferentiated (embryonal) sarcoma of the liver: report of three cases

Undifferentiated (embryonal) sarcoma is a rare malignant tumor of the liver. It typically presents in late childhood and its prognosis is poor. We experienced three cases of such a tumor during the period of 1976-1989; two of these patients are still alive without disease. Each case was independently treated with a combination of surgery and pre- and/or postoperative chemotherapy, which was found to be effective. In one surviving patient, cyclophosphamide and vincristine were found to be effective, while in the other a combination of cisplatin, Adriamycin (ADM), vincristine and cyclophosphamide was observed to induce a rapid reduction in the size of the recurrent tumor. Thus, an adequate combination of surgery and chemotherapy may improve the prognosis of this tumor.

Undifferentiated sarcoma of the liver in childhood: morphology, flow cytometry, and literature review

Nine cases of undifferentiated sarcoma of the liver in childhood were investigated by conventional light microscopy, immunohistochemistry, and DNA flow cytometry. Different histologic patterns were discernible. In some cases, areas resembling poorly differentiated rhabdomyosarcoma were present. This histologic diversity was supported by the immunohistologic detection of desmin and cytokeratins in five cases. When evaluated by flow cytometry, four of five cases investigated were diploid; only one was aneuploid, and this patient had the most aggressive course. Follow-up investigations of our patients and those described in the literature revealed that the prognosis of this type of tumor is not as bad as is generally assumed. Of the patients reported in the literature with detailed follow-up information, 37.5% survived without evidence of disease for an average of 37.5 months, death occurred in 47.5% after an average of 11.9 months, and 15.0% were alive with disease.

Undifferentiated (embryonal) sarcoma of the liver: ultrastructure, immunohistochemistry, and DNA ploidy analysis of two cases

We describe the histopathologic, immunohistochemical, electronmicroscopic features, and DNA flow cytometric analysis of 2 cases of undifferentiated (embryonal) sarcoma of the liver. The tumor cells were found to be uniformly nonreactive to antibodies that identify cells belonging to the macrophagic-monocytic system. Focal expression of cytokeratin was an unexpected finding. We conclude that the observations are compatible with origin of this sarcoma from primitive mesenchyme. Uncertainty still exists about histogenesis, but the morphologic features of this neoplasm are quite characteristic. Both tumors demonstrate aneuploid stem lines with high S phase. Whether these findings are prognostically significant remains to be seen.

Undifferentiated (embryonal) sarcoma of the liver. Epithelial features as shown by immunohistochemical analysis and electron microscopic examination

The cell differentiation properties of two undifferentiated (embryonal) sarcomas of the liver (USL), one in a 9-year-old boy and one in a 23-year-old man, were studied by immunohistochemistry and electron microscopic examination. Both tumors showed a part pleomorphic pattern and a part myxoid spindle cell sarcomatous pattern. An electron microscopic examination showed some tonofilament-like bundles of intermediate filaments and cell junctions in one case, suggesting the presence of epithelial differentiation in that tumor. An immunohistochemical analysis showed a large number of cytokeratin-positive neoplastic cells in both cases as studied with two different monoclonal antibodies, and most cells were positive for vimentin. No cells showed desmin, glial fibrillary acidic protein, or epithelial membrane antigen (EMA). Due to the presence of cytokeratin immunoreactivity, the possibility was considered that these tumors would represent anaplastic sarcomatoid variants of hepatocellular carcinoma. The tumor cells showed cytoplasmic alpha-1-antitrypsin (AAT) positivity, and were negative for alpha-fetoprotein. Because the immunoreactivity of AAT is widespread in different types of tumors, it is not possible to conclude that the AAT positivity would indicate the hepatoma nature of USL; however, this remains a possibility, especially when considering that in vitro transformed hepatocytes have been shown to be capable of forming sarcomatous tumors.

Undifferentiated (embryonal) sarcoma of the liver. A clinicopathologic study of a survivor treated with combined technique therapy

Undifferentiated (embryonal) sarcoma is one of the less common primary malignant tumors of the liver that typically, although not exclusively, presents in later childhood. It has come to be recognized as an aggressive neoplasm with the potential for local recurrence and distant metastasis, despite a seemingly successful total surgical resection. This report documents our experience with an 8-year-old boy who had an 80% hepatectomy for an undifferentiated (embryonal) sarcoma, followed by cisplatin (90 mg/m2), doxorubicin (20 mg/m2/d), and radiation therapy (1950 cGy) to the tumor bed. Residual microscopic tumor was very likely present in the region of the inferior vena cava, but exploratory laparotomies for the purpose of "second-look" biopsies were performed with negative results after the completion of each course of chemotherapy. The patient is off of treatment and disease-free 30 months after the diagnosis. Because the survival at this time has been so poor for this highly malignant tumor, we suggest that the combination of therapeutic techniques and second-look laparotomy(s) to identify any subclinical tumor may be a reasonable approach. Ultrastructural and immunohistochemical studies by us and other investigators indicate that the neoplastic cells are primitive mesenchymal cells by electron microscopic study and have immunoreactivity limited to vimentin, alpha-1-antitrypsin, and alpha-1-antichymotrypsin.