Hepatic undifferentiated (embryonal) sarcoma arising in a mesenchymal hamartoma

Treatment of Undifferentiated Embryonal Sarcoma of the Liver in Children

Undifferentiated embryonal sarcoma of the liver is a rare mesenchymal tumor with a highly malignant potential. It occurs almost exclusively in the pediatric population and typically has a poor outcome. Although previous studies have reported dismal prognoses, recent advances in combined treatment modalities, e.g., surgery and chemotherapy, have given cause for optimism. Even in those diseases not amenable to complete surgical resection or refractory diseases, other treatment modalities, such as liver transplant, have yielded promising results. This paper provides a review of the current treatment modalities for hepatic undifferentiated embryonal sarcoma in children.

Case Report of Undifferentiated Hepatic Embryonal Sarcoma with Mesenchymal Hamartoma: A Rare Entity

Undifferentiated embryonal sarcoma (UES) is a highly malignant hepatic neoplasm, which occurs mostly in pediatric population. There is a link between embryonal sarcoma and mesenchymal hamartoma as evidenced by clinicopathological overlap and similar genetic abnormality. Here, we report a case of UES in a young female in a background of mesenchymal hamartoma of liver.

Undifferentiated embryonal sarcoma of the liver: A rare hepatic tumor and its related characteristic radiological features

The undifferentiated embryonal sarcoma of the liver is a rare tumor with a poor prognosis, with improved outcomes being reported with more recently multimodality treatments. We report a case of a 6-year-old girl with an incidentally diagnosed and histologically proven localized undifferentiated embryonal sarcoma of the liver. The divergence between solid appearance at US and cystic-like appearance on CT/MRI, which has been attributed to the presence of myxoid component frequently described with this tumor, was crucial for the diagnosis and subsequent treatment.

Mesenchymal hamartoma and undifferentiated embryonal sarcoma: diagnostic keys that radiologists need to know

OBJECTIVE

Hepatic tumors are uncommon in pediatric patients. Among the most common of these uncommon tumors are mesenchymal hamartoma and undifferentiated embryonal sarcoma, which have different origins but similar appearance on imaging studies. This paper reviews the characteristic findings and differential diagnosis of these entities. Ultrasonography is the first-line imaging test to study these tumors. Magnetic resonance imaging and computed tomography are useful for further characterizing the tumors and planning surgery.

CONCLUSION

Radiologists need to be familiar with the imaging findings of the different disease entities and to evaluate them together with the patient's age, personal history, and bloodwork.

Undifferentiated sarcoma of the liver: Multicenter international experience of the Cooperative Soft-Tissue Sarcoma Group and Polish Paediatric Solid Tumor Group

BACKGROUND

Undifferentiated embryonal sarcomas of the liver (UESL) are extremely rare and continue to pose a diagnostic and therapeutic challenge. The aim of the study was to present a multicenter experience of the German CWS and Polish PPSTG groups in the treatment of UESL in children.

PROCEDURE

Twenty-five patients were treated according to the CWS-96, CWS-2002, and CYVADIC protocols. Distant metastases were observed in four cases (16%). In four cases, an initial disease presentation mimicked other entities. A pure cystic appearance of liver mass led to misdiagnosis of hydatid cyst in three cases. In one case, laparotomy was performed due to the signs of appendicitis, and bleeding from ruptured liver tumor was found. All these patients were finally diagnosed as UESL.

RESULTS

Thirteen patients received preoperative chemotherapy. Partial response was observed in 10 cases. Tumor resection was performed in 20 patients (primary resections, 12; delayed resections-, 8). In five patients, the primary tumor never became operable. The macroscopically complete resection rate was 95% (19/20). Postoperative chemotherapy was given to 20 children. Local radiotherapy was used in three children. After a median follow-up time of 136 months, 17 patients (68%) were alive with no evidence of disease. All children with unresectable tumor and three out of four patients with distant metastases died. The five-year overall survival (OS) rate was 72%.

CONCLUSIONS

In summary, a complete tumor excision plays the central role in the treatment of UESL. A cystic presentation of the liver lesion on imaging does not exclude the diagnosis of malignant tumor.

Undifferentiated embryonal sarcoma of the liver: Clinical characteristics and outcomes

BACKGROUND

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare liver malignancy originating from primary mesenchymal tissue. The clinical manifestations, laboratory tests, and imaging examinations of the disease lack specificity and the preoperative misdiagnosis rate is high. The overall prognosis is poor and survival rate is low.

AIM

To investigate the diagnosis, treatment, and prognosis of UESL.

METHODS

We performed a retrospective, single-center cohort study in Shengjing Hospital of China Medical University, which is a central hospital in northeast China. From 2005 to 2017, we recruited 14 patients with pathologically confirmed UESL. We analyzed the clinical manifestations, laboratory tests, imaging examinations, pathological examinations, therapy, and prognosis of these patients.

RESULTS

There were nine males and five females aged 2-60 years old included in the study. The major initial symptoms were abdominal pain (71.43%) and fever (57.14%). Preoperative laboratory tests revealed that seven patients had increased leukocyte levels, four showed a decrease in hemoglobin levels, seven patients had increased glutamyl transpeptidase levels, nine had increased lactate dehydrogenase levels, and three showed an increase in carbohydrate antigen 199. There was no difference in the rate of misdiagnosis in preoperative imaging examinations of UESL between adults and children (6/6 vs 5/8, P = 0.091). The survival rate after complete resection was 6/10, while that after incomplete resection was 0/4 (P = 0.040), suggesting that complete resection is important to improve survival rate. In total, five out of the eight children achieved survival. During the follow-up, the maximum survival time was shown to be 11 years and minimum survival time was 6 mo. Six adult patients relapsed late after surgery and all of them died.

CONCLUSION

Preoperative imaging examination for UESL has a high misdiagnosis rate. Multidisciplinary collaboration can improve the diagnostic accuracy of UESL. Complete surgical resection is the first choice for treatment of UESL.

Undifferentiated Embryonal Sarcoma of the Liver Identified after the Initial Diagnosis of a Hepatic Cyst

Abdominal ultrasound in a 50-year-old Japanese man revealed a cystic lesion on the caudate lobe of the liver. Four-month follow-up imaging showed a rapid increase in the size of the cystic lesion. The patient underwent laparoscopic partial hepatectomy because of a suspicion and perceived risk that the lesion might be malignant. The initial histological diagnosis was a hepatic cyst. Eleven months later, computed tomography showed a giant cystic lesion in the abdominal cavity and multiple liver metastases. The patient underwent excision of the giant cystic lesion and a partial hepatectomy. Immunohistochemistry for the recurring lesion revealed undifferentiated embryonal sarcoma of the liver.

Hepatic mesenchymal hamartoma and undifferentiated embryonal sarcoma of the liver: a pathologic review

This review highlights two rare entities that are predominantly seen in children: hepatic mesenchymal hamartoma (HMH) and undifferentiated embryonal sarcoma of the liver (UESL). HMH is a benign lesion predominantly seen in the first 2 years of life, while UESL is malignant and usually identified in patients between 6 and 10 years of age. UESL may arise in the background of HMH, and the association has been supported by similar chromosomal aberrations (19q13.4). The diagnosis of both lesions is primarily based on histologic evaluation, as the clinical and radiological features are not always typical. The clinicopathologic characteristics, pathogenesis, differential diagnoses and treatment for both lesions are discussed.

Atypical Hepatic Mesenchymal Hamartoma: Histologic Appearance, Immunophenotype, and Molecular Findings

Hepatic mesenchymal hamartoma is a rare benign neoplasm principally encountered in young children. Its origin is unknown. We report an unusual hepatic mesenchymal hamartoma in a 7-month-old girl, including histopathologic findings, immunophenotype, and karyotype. Chromosomal microarray analysis of tumoral tissue and circulating lymphocytes found 4 copies of a segment at 1q44 and fluorescence in situ hybridization indicated tandem triplication, ascribed to expansion of a paternal tandem duplication. This genetic abnormality may have played a role in pathogenesis.

Undifferentiated embryonal sarcoma of the liver in adult patient: A report of two cases

Primary sarcomas of the liver are unusual neoplasms developing in adults. They constitute a heterogeneous group of neoplasms including undifferentiated embryonal sarcoma. Patients usually present with an abdominal mass and abdominal pain. Case 1: A 53-year-old woman presented with abdominal pain. Computed tomography showed an occupying mass in the right lobule and an intra-auricular multi-lobulated mass suggestive of a secondary deposit. Biopsy of the hepatic lesion revealed undifferentiated embryonal sarcoma. Despite radiotherapy and supportive measures, her overall status progressively worsened until cardiac arrest. Case 2: A 41-year-old woman presented with hepatomegaly. Abdominal imaging showed cystic lesions in the right hepatic lobule with multiple septae. The patient underwent extended right hepatectomy and a histopathological study reported high-grade undifferentiated embryonal sarcoma. Two years after surgery, a new cystic lesion in the surgical site was recorded and chemotherapy was scheduled. The lesion remained stable for three years when disease progression was observed and second-line chemotherapy was initiated. Although undifferentiated embryonal sarcoma of the liver has poor prognosis, early diagnosis is essential to increase the chances of survival. Currently, surgical resection and chemotherapy are the primary treatment modalities.

Unexpected Liver Embryonal Sarcoma in the Adult: Diagnosis and Treatment

Undifferentiated embryonal sarcoma of the liver is a malignancy with poor prognosis observed more frequently in children between 6 and 10 years old and very rarely found in adults. We present a case of embryonal sarcoma of the liver in a 60-year-old woman without significant medical history who presented to our attention with constitutional symptoms. Preoperative assessments did not show alterations in blood chemistry or tumor markers. Imaging studies showed a huge mass lying in the right abdominal quadrants, strictly adherent to the liver. The tumor was partially cystic with a thickened wall, sporadic contrast enhancement, and solid component. The patient underwent excision of the mass with associated liver bisegmentectomy S5-S6. Postoperative course was uneventful. The definitive histological diagnosis revealed the presence of embryonal sarcoma of the liver. We describe the clinical, histopathological, and therapeutic options adopted in the multimodal treatment of this disease.

A 4 and a half years old boy with mesenchymal hamartomas in the left lateral lobe of the liver: A case report and literature review

RATIONALE

Mesenchymal hamartomas of the liver is one type of rare liver tumor.

PATIENT CONCERNS

Mesenchymal hamartomas of the liver (MHL) is rarely reported in the left lobe of the liver in children who are more than 2 years old. It is difficult to distinguish it from liver lesions such as hepatoblastoma in children, and hepatocellular carcinoma and focal nodular hyperplasia in adults. In addition, it is hard to correctly diagnose it without pathological examination.

DIAGNOSES

Mesenchymal hamartomas of the liver.

INTERVENTIONS

This patient underwent an operation assisted by the Da Vinci surgical system and the tumor was completely resected.

OUTCOMES

No tumor recurrence or metastasis was observed 14 months after operation.

LESSONS

MHL is a benign tumor that is difficult to diagnose due to the lack of specific clinical symptoms and signs. The management of MHL remains controversial. To achieve a good long-term outcome, complete resection of MHL is recommended.

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.

Imaging features of undifferentiated embryonal sarcoma of the liver: a series of 15 children

BACKGROUND

Undifferentiated embryonal sarcoma of the liver is a rare malignant mesenchymal tumour occurring mostly in children ages 6-10 years. The discrepancy between its solid appearance on US and cystic-like appearance on CT has been described.

OBJECTIVE

To study the imaging particularities and similarities among our cases of undifferentiated embryonal sarcoma and to report the errors in initial diagnoses.

MATERIALS AND METHODS

We conducted a retrospective study of 15 children with undifferentiated embryonal sarcoma diagnosed or referred to our hospital during 1997-2015 and analysed the clinical, biological and imaging data.

RESULTS

We identified eight boys and seven girls ages 9 months to 14 years. Ten children presented with abdominal pain. Alpha-fetoprotein was slightly increased in one. Initial US and CT had been performed for all, while additional MRI had been done in two children. Initial CT demonstrated a hypoattenuated mass in all. Rupture was seen in five and intratumoural bleeding in seven children. Tumour volumes reduced during neoadjuvant chemotherapy in 10 children.

CONCLUSION

Undifferentiated embryonal sarcoma might be suggested in a non-secreting unifocal tumour with well-defined borders, fluid-filled spaces on US, hypoattenuation and serpiginous vessels on CT, and if there are signs of internal bleeding or rupture on CT or MRI.

Mesenchymal Hamartoma of the Liver in Older Children: An Adult Variant or a Different Entity? Report of a Case With Review of the Literature

Mesenchymal hamartoma of the liver (MHL) is an uncommon benign hepatic tumor typically affecting children under 2 years of age. Only 5% of MHL occur after 5 years and are very rarely observed in adults. According to age, MHL may differ in their morphologic features. We report a case of an 11-year-old boy with MHL, resembling a malignant lesion from a clinical point of view, characterized by unusual histologic features: a prominent myxoid stroma, with a minimal ductular component, and absent cystic spaces. The present case and others reported in older children or adults demonstrate that these lesions may represent a potential diagnostic pitfall when occurring outside their classic clinical context especially because of their peculiar histologic findings. Moreover, it may be hypothesized that variation in morphology might be related to different evolutive stages of the cell of origin. To support this hypothesis, we therefore studied the presence of components of the Notch pathway inside and outside the lesion. Their absence inside the tumor and, in contrast, the expression of Notch2 and HES1 evident in overrepresented bile ducts present at the periphery might explain not only the lack of bile ducts, but also indicate a more adult phenotype compared with classic pediatric MHL, which show more bile ducts and liver trabeculae embedded in the mesenchymal matrix.

Pathologic Features of Primary and Metastatic Hepatic Malignancies

In the mammalian liver, 60 % of the cellular components are hepatocytes while the remainder (35 %) includes biliary epithelium, Kupffer cells, endothelial cells, fat storing cells and connective tissue cells. Although neoplasms of hepatocytes are the most common, a significant number of both benign and malignant primary liver neoplasms arising from other cell types can develop, such as tumors of bile duct epithelium (Table 1). In addition, the liver is one of the most susceptible sites for metastatic tumors arising from other organs of the body. Not too long ago, liver tumors were left untreated because the liver was considered a complex and mysterious organ inaccessible to surgery. Advances in imaging procedures and surgical techniques over the past 40 years have revolutionized the approaches to the treatment of benign and malignant liver tumors. Subsegmentectomy, segmentectomy, lobectomy, and transplantation are routinely performed for the treatment of primary and metastatic liver tumors with minimal morbidity and mortality. Since accurate diagnosis remains the key to clinical and surgical management, the emphasis of this chapter is on classification, morphological features and differential diagnosis of malignant neoplasms of the liver.

Undifferentiated Embryonal Sarcoma of Liver

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant hepatic tumor. A 47 year old male presented with symptoms of sour taste in his mouth, occasional nausea, indigestion and 15-pound weight loss over two months. He had an unremarkable upper gastrointestinal endoscopy. Imaging showed a large liver mass in the left hepatic lobe that was resected and then reported as UESL. He went on to develop lung metastases and was initially treated with doxorubicin and ifosfamide followed by switching of therapy to gemcitabine and docetaxel due to progression of disease. He had a good response after two cycles and went on to receive four more cycles, achieving stable disease. We can therefore conclude that the combination of gemcitabine and docetaxel is a potential therapeutic option for patients with UESL.

Undifferentiated embryonal sarcoma of the liver: a concise review

Undifferentiated embryonal sarcoma of the liver is an aggressive mesenchymal tumor that occurs predominantly in children. Although this entity has been described for decades, its pathogenesis is still obscure. Its association with mesenchymal hamartoma has been well described on the basis of identical chromosomal abnormalities. The clinical and radiological diagnoses are often difficult, and the diagnosis of undifferentiated embryonal sarcoma of the liver is based on its histology and immunophenotype. It is essential to recognize the characteristic histologic findings and the pattern of the immunohistochemistry staining to rule out other hepatic lesions. Multimodal therapy with surgery, chemotherapy, and radiation therapy has drastically improved the prognosis of patients with undifferentiated embryonal sarcoma of the liver. This successful management requires timely diagnosis for superior outcome.

Mesenchymal hamartoma or embryonal sarcoma of the liver in childhood: a difficult diagnosis before complete surgical excision

BACKGROUND

Clinical experience shows that the primary diagnosis of mesenchymal hamartoma (MHL) and embryonal sarcoma of the liver (ESL) recurrently is mistaken, leading to inadequate managements. We evaluated the accuracy of the primary diagnosis of those liver tumors, compared with the final histological diagnosis.

METHODS

Records of 25 children (0-16 years, treated 01/1989-01/2013) with final diagnosis of MHL or ESL were analyzed.

RESULTS

Final diagnosis was MHL in 18/25 children (10 solid-cystic, 2 cystic, 6 solid) and ESL in 7/25 (4 solid-cystic, 1 cystic, 2 solid). Only 3/7 ESL patients and 15/18 MHL patients fell into the "typical" age group. In 13/25 children primary diagnosis was based on imaging only. Overall, primary diagnosis was concordant with the final diagnosis in 17/25 patients. Of 99/25 biopsied cases, 4/9 biopsy results exposed the wrong final diagnosis; of cystic-solid masses 4/14 were mistaken, of cystic masses 1/3, of solid masses 3/8.

CONCLUSION

Preoperative diagnosis of MHL and ESL is challenging because of atypical clinical presentation, misleading "typical" radiological findings, and difficult interpretation of biopsies. If feasible, complete surgical resection of, in particular, solid-cystic liver masses in the pediatric age group must be aimed for, to get a definitive, final diagnosis, followed by an adequate treatment strategy.

Activation of the chromosome 19q microRNA cluster in sporadic and androgenetic-biparental mosaicism-associated hepatic mesenchymal hamartoma

Recurrent genetic alterations found in hepatic mesenchymal hamartoma include either androgenetic-biparental mosaicism or chromosomal rearrangements involving chromosome 19q13.4, in the vicinity of the chromosome 19q microRNA cluster (C19MC). Abnormal activation of C19MC, which is subject to paternal imprinting and is normally expressed only in placenta, could account for both genetic associations because androgenetic cells carry only paternal chromosomes. In this study, a 4.2-Mb deletion involving the 5'-end of C19MC was detected in a sporadic mesenchymal hamartoma by chromosomal microarray. Fluorescence in situ hybridization studies showed that the deletion localized to mesenchymal cells in the stroma of the hamartoma. Quantitative real-time polymerase chain reaction analysis of this tumor, 9 other sporadic hepatic mesenchymal hamartomas, and 3 hamartomas associated with androgenetic-biparental mosaicism demonstrated C19MC microRNA expression in all but 2 sporadic cases, with no significant expression in control liver. The findings support a pathogenetic model for mesenchymal hamartoma as a consequence of "ectopic" activation of C19MC in hepatic stroma, due to either chromosomal rearrangements or paternal uniparental disomy.

Characterization of translocations in mesenchymal hamartoma and undifferentiated embryonal sarcoma of the liver

BACKGROUND

Mesenchymal hamartoma of the liver (MHL) is an uncommon benign primary liver tumor that typically occurs in the pediatric population, although cases have been described in adults. MHL is sometimes associated with the highly malignant undifferentiated embryonal sarcoma (UES), and the synchronous or metachronous occurrence of MHL and UES suggests they share a common genetic link. Although the exact mechanism of tumorigenesis has not been identified, MHL cases harbor recurring chromosomal rearrangements involving 19q13.

DESIGN

In order to provide more details on the genetic events of MHL tumorigenesis, capture-based next generation sequencing (NGS) targeted to loci recently shown to be involved in a translocation in a case of UES arising in MHL (specifically, the MALAT1 gene on chromosome 11 and a gene poor region termed MHLB1 on chromosome 19) was performed on formalin fixed paraffin embedded tissue from seven cases of MHL.

RESULTS

Chromosome rearrangements involving the MHLB1 locus were identified in three of the seven cases, including the translocation t(11,19)(q13.1;q13.42) involving the MALAT1 gene; the translocation t(2,19)(q31.1;q13.42) involving AK023515, an uncharacterized noncoding gene; and the inversion inv(19,19)(q13.42;q13.43) involving the PEG3 gene encoding a Kruppel-type zinc-finger protein. Rearrangements were exclusively identified in pediatric tumors. In each case, the presence of the rearrangement was confirmed by PCR and interphase FISH. Interphase FISH also demonstrated that the arrangements occur within the spindle cell component but not within the epithelial components of the tumor.

CONCLUSIONS

Since the MHLB1 locus contains a CpG-rich region whose methylation regulates C19MC miRNA genes, rearrangements that disrupt this region may contribute to MHL development through alteration of miRNA expression. The demonstration that the loose stromal cells harbor the rearrangements indicates that (some cases of) MHL are a neoplastic process due to a somatic genetic change and not a germline abnormality.

Undifferentiated sarcoma of the liver: a case study of an erythropoietin-secreting tumor

Undifferentiated embryonal sarcoma of the liver (UESL) is an uncommon hepatic tumor usually found in children, with rare cases reported in adults. We present a case of a 53-year-old woman with an undifferentiated sarcoma of the liver (USL), which resembles UESL, who initially presented with a markedly elevated hematocrit (61.2%). Cytogenetic studies for polycythemia vera were negative, but the patient's erythropoietin (EPO) was elevated. A computed tomography scan and subsequent partial hepatectomy revealed a well-circumscribed, partially cystic mass in the right lobe of the liver measuring 34 cm. Following surgery, the patient's EPO level and hematocrit dropped to within normal range and remained so for 1 year, at which point it rose again. A subsequent magnetic resonance imaging scan showed a liver mass at the previous resection margin, consistent with a recurrence. In this case study, we describe the first reported USL resembling an UESL that secretes EPO, which was a useful marker of tumor recurrence.

Hepatic mesenchymal hamartoma in a neonate with a Bochdalek diaphragmatic hernia: a case report

The Bochdalek diaphragmatic hernia (BDH) is a common birth defect that is associated with other congenital malformations. Hepatic mesenchymal hamartoma (HMH) is the second most common benign hepatic tumor in children. The association between BDH and HMH or ectopic hepatic tissue is uncommon. We report a case of a female newborn with a left BDH that at surgery was incidentally found to have a tumor of 3.5 cm in maximum dimension with a serous muscular membrane. The histopathological study revealed vascular-mesenchymal stroma with bile ducts entrapped and peripheral normal hepatic tissue. These findings correlate with the diagnosis of hepatic mesenchymal hamartoma (HMH) in ectopic hepatic tissue. Our objective is to report a case of a rare association between HMH and BDH as well as discuss its differential diagnosis.

Undifferentiated embryonal sarcoma of the liver with focal osteoid picture-a case report

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare primary liver tumor. Less than 100 adult cases were reported. It has female and right lobe preponderance. In pathological features, focal osteoid picture in UESL is never reported. We present a 63-year-old male patient with left lobe UESL with focal osteoid picture. He was admitted for a palpable solid mass, with left upper quadrant abdominal pain for 4 months. Abdominal computed tomography showed a huge well-circumscribed mass at left upper quadrant, 21.3 × 13 × 27.9 cm(3) in size, with multiple septa in delayed phase. En bloc resection including lateral segmentectomy, splenectomy, and cholecystectomy were performed, but tumor rupture was noted. The pathologic diagnosis was ruptured UESL. The postoperative course was uneventful, and adjuvant radiotherapy without chemotherapy was performed. Peritoneal seeding with massive ascites was noted in the 9(th) month after operation. Even after receiving salvage chemotherapy, he died 1 year after operation. Early complete surgical resection with adjuvant chemotherapy may improve prognosis of UESL. But the overall survival of UESL did not improve until recently. We present this case along with a literature review of the clinical pictures, diagnosis, pathology presentation, pathologicogenesis of focal osteoid picture, treatment, and prognosis for UESL of another 23 new reported cases since 2007.

Soft tissue tumors of uncertain origin

Many soft tissue tumors of childhood lack obvious differentiation toward a defined mesenchymal tissue type or have a phenotype that does not correspond to any defined normal tissue. These challenging tumors are currently regarded as neoplasms of uncertain differentiation. Nonetheless, there have been great strides in the understanding of their pathologic and genetic features and biologic underpinnings. The application of new genetic information to the pathologic diagnosis among this group of tumors is an emerging area in diagnostic pediatric pathology. This article reviews the clinicopathologic features of tumors of uncertain and/or miscellaneous origin, with an emphasis on the unique aspects of these neoplasms in children and adolescents, use of diagnostic adjuncts, and differential diagnosis.

Molecular cytogenetic characterization of undifferentiated embryonal sarcoma of the liver: a case report and literature review

Undifferentiated embryonal sarcoma of the liver (UESL) represents a heterogeneous group of tumors derived from mesenchymal tissues. Earlier cytogenetic studies in limited cases demonstrated that UESL is associated with a recurrent translocation t(11;19)(q11;q13.3-q13.4) or add(19)(q13.4). In this report, we present our array comparative genomic hybridization (aCGH), fluorescence in situ hybridization (FISH) findings, and a missense mutation of TP53 gene by DNA sequencing in a 19-year-old patient with UESL. The data were compared to laboratory findings reported by previous studies.

Expression of glypican-3 in undifferentiated embryonal sarcoma and mesenchymal hamartoma of the liver

Glypican-3 (GPC3) is an oncofetal protein that has been demonstrated to be a useful diagnostic immunomarker for hepatocellular carcinoma and hepatoblastoma. Its expression in mesenchymal tumors of the liver, particularly undifferentiated embryonal sarcoma (UES) and mesenchymal hamartoma (MH), has not been investigated. In this study, a total of 24 UESs and 18 MHs were immunohistochemically stained for GPC3 expression. The results showed cytoplasmic staining for GPC3 in 14 (58%) UESs, of which 6 exhibited diffuse immunoreactivity and the remaining 8 showed focal positivity. The patients with GPC3-positive UES tended to be younger (mean 18 years; median 11 years) than those with GPC3-negative tumors (mean 39.4 years; median 27 years), although the difference did not reach statistical significance (P = .06). Eight MHs also exhibited GPC3 immunoreactivity (44%; 4 diffuse and 4 focal). Positive staining in all 8 cases was primarily seen in entrapped nonlesional hepatocytes with a canalicular and cytoplasmic staining pattern. In only 4 cases (22%) was GPC3 immunoreactivity also observed in the mesenchymal component. The patients with positive staining also tended to be younger (mean 2.6 years; median 1.1 years) compared with those with negative staining (mean 16.3 years; median 4.5 years), but the difference was not statistically significant (P = .15). Our data demonstrate that GPC3 is expressed in a subset of UES and MH of the liver. Caution should thus be exercised when evaluating a GPC3-expressing hepatic neoplasm, particularly on a needle biopsy when the differential diagnosis includes poorly differentiated hepatocellular carcinoma or hepatoblastoma.

Occult androgenetic-biparental mosaicism and sporadic hepatic mesenchymal hamartoma

The incidence of hepatic mesenchymal hamartoma (HMH) is increased in patients with placental mesenchymal dysplasia (PMD), which appears to be caused by androgenetic-biparental mosaicism (ABM). We hypothesized that occult ABM might underlie cases of HMH with no known history of PMD. Formalin-fixed, paraffin-embedded HMH specimens from 10 such patients and liver specimens from 6 non-HMH controls were identified retrospectively from the surgical pathology records of a pediatric hospital. The relative abundance of maternal and paternal alleles was assessed by quantitative polymerase chain reaction amplification of polymorphic short tandem repeats and single nucleotide polymorphisms located on 15 different chromosomes. Androgenetic-biparental mosaicism was diagnosed in one patient based on global allelic imbalances at all informative loci. In that patient, the greatest imbalances were observed in stroma-rich portions of the hamartoma, with no significant imbalance in histologically normal liver or epithelium-rich portions of the hamartoma. A retrospective, unbiased review of the histology and clinical records from all 10 patients revealed no morphologic or clinical correlates to distinguish the affected patient, except that she had multiple cutaneous hemangiomas, which like HMH, appear to be more common in patients with PMD. Our findings suggest that other patients with apparently sporadic HMH, hemangioma, or other lesions seen more frequently with PMD may harbor occult ABM. Recognition of ABM may be important because its long-term consequences are unknown but may be significant.

Mesenchymal hamartoma of the liver with inversion of chromosome 19

ABSTRACT A mesenchymal hamartoma of the liver (MHL) from a 20-month-old girl was studied cytogenetically. The karyotype was 46,XX,inv(19)(p13q13.4)[38], and fluorescence in situ hybridization using bacterial artificial chromosome probes refined the breakpoints to 19p13.11 and the subtelomeric region of 19q. This is the first report of inversion (19) in MHL, and the q-arm breakpoint is different from that reported previously in other rearrangements.

Hepatobiliary tumors

The investigation of hepatobiliary tumors, in the pediatric population, usually begins with an ultrasonographic (US) examination. It is readily available without ionizing radiation and does not need sedation. Therefore US is an outstanding imaging modality for screening and follow-up. Doppler and color Doppler interrogation are part of the examination to assess vascularity of the lesions and vascular anatomy. Magnetic resonance imaging is a comprehensive imaging modality with multiplanar capability to assess the liver parenchyma, gallbladder, and biliary tree and is free of ionizing radiation. This article highlights the current status of imaging of the most common hepatobiliary tumors in children.

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.

Undifferentiated embryonal sarcoma of the liver is associated with mesenchymal hamartoma and multiple chromosomal abnormalities: a review of eleven cases

Undifferentiated embryonal sarcoma (UES) of the liver is a primitive mesenchymal, malignant neoplasm occurring in children. The link between UES and mesenchymal hamartoma (MH) is controversial. Whether they share the same histiogenesis, representing 2 ends of a spectrum, or are distinct entities is unclear. The genetic aberrations of these neoplasms are not well understood, although a common breakpoint (19q13.4) was recently identified. The purpose of this study was to elucidate immunohistochemical markers that may establish a link between the 2 tumors by reviewing cases of UES and MH. Cases of UES from 1990 to 2008 were identified. Clinical demographics were reviewed. Hematoxylin and eosin staining and immunohistochemical staining for vimentin, alpha-1 antitrypsin, and alpha-fetoprotein were performed. Eleven children were diagnosed with UES. Five cases were seen arising in association with MH, and transitional zones were evident. The mean age at presentation was 10 years. To our knowledge, the 11-month-old patient is the youngest reported case of UES in concurrence with MH. All UES tumor cells were positive for vimentin, diastase-resistant periodic acid-Schiff stain, and alpha-1 antitrypsin. Chromosomal analysis of 3 UES cases, 2 arising with MH, showed complex karyotypes with no involvement of 19q13.4. We suggest a continuum between UES and MH. Although a chromosomal anomaly of 19q13.4 was not identified, a submicroscopic involvement of this locus cannot be excluded. Additionally, our analyses suggest that multiple chromosomal aberrations may be associated with the MH/UES spectrum.

ARTEMIS stabilizes the genome and modulates proliferative responses in multipotent mesenchymal cells

Background

Unrepaired DNA double-stranded breaks (DSBs) cause chromosomal rearrangements, loss of genetic information, neoplastic transformation or cell death. The nonhomologous end joining (NHEJ) pathway, catalyzing sequence-independent direct rejoining of DSBs, is a crucial mechanism for repairing both stochastically occurring and developmentally programmed DSBs. In lymphocytes, NHEJ is critical for both development and genome stability. NHEJ defects lead to severe combined immunodeficiency (SCID) and lymphoid cancer predisposition in both mice and humans. While NHEJ has been thoroughly investigated in lymphocytes, the importance of NHEJ in other cell types, especially with regard to tumor suppression, is less well documented. We previously reported evidence that the NHEJ pathway functions to suppress a range of nonlymphoid tumor types, including various classes of sarcomas, by unknown mechanisms.

Results

Here we investigate roles for the NHEJ factor ARTEMIS in multipotent mesenchymal stem/progenitor cells (MSCs), as putative sarcomagenic cells of origin. We demonstrate a key role for ARTEMIS in sarcoma suppression in a sensitized mouse tumor model. In this context, we found that ARTEMIS deficiency led to chromosomal damage but, paradoxically, enhanced resistance and proliferative potential in primary MSCs subjected to various stresses. Gene expression analysis revealed abnormally regulated stress response, cell proliferation, and signal transduction pathways in ARTEMIS-defective MSCs. Finally, we identified candidate regulatory genes that may, in part, mediate a stress-resistant, hyperproliferative phenotype in preneoplastic ARTEMIS-deficient MSCs.

Conclusions

Our discoveries suggest that Art prevents genome damage and restrains proliferation in MSCs exposed to various stress stimuli. We propose that deficiency leads to a preneoplastic state in primary MSCs and is associated with aberrant proliferative control and cellular stress resistance. Thus, our data reveal surprising new roles for ARTEMIS and the NHEJ pathway in normal MSC function and fitness relevant to tumor suppression in mesenchymal tissues.

From the archives of the AFIP: Pediatric liver masses: radiologic-pathologic correlation part 1. Benign tumors

Benign hepatic tumors in children include lesions that are unique to the pediatric age group and others that are more common in adults. Infantile hemangioendothelioma, or infantile hepatic hemangioma, is a benign vascular tumor that may cause serious clinical complications. It is composed of vascular channels lined by endothelial cells. At imaging, large feeding arteries and draining veins and early, intense, peripheral nodular enhancement with centripetal filling on delayed images are characteristic features. Mesenchymal hamartoma of the liver occurs in young children and is characterized pathologically by mesenchymal proliferation with fluid-containing cysts of varying size and number. The mesenchymal component or cystic component may predominate; this predominance determines the imaging appearance of the tumor. Benign epithelial tumors that are common in adults may infrequently occur in childhood. These include focal nodular hyperplasia (FNH), hepatocellular adenoma, and nodular regenerative hyperplasia. All are composed of hyperplastic hepatocytes similar to surrounding liver parenchyma and may be difficult to discern at imaging. Preferential hepatic arterial phase enhancement helps distinguish FNH and hepatic adenoma from uninvolved liver. Hepatic adenoma often has intracellular fat and a propensity for intratumoral hemorrhage, neither of which are seen in FNH. Unlike adenoma, FNH often contains enough Kupffer cells to show uptake at sulfur colloid scintigraphy. Nodular regenerative hyperplasia is often associated with portal hypertension, which may be evident at imaging. Knowledge of how the pathologic features of these tumors affect their imaging appearances helps radiologists offer an appropriate differential diagnosis and management plan.

Adult Mesenchymal Hamartoma of the Liver: Case Report and Literature Review

Mesenchymal hamartoma of the liver (MHL) is a rare benign lesion occurring primarily in the pediatric population. While the precise pathogenesis of the tumor is not certain, the most common theory relates to aberrant mesenchyme development in the portal tract likely related to the bile ducts. A 53-year-old female was evaluated for an incidental liver mass. Initial CT scan showed a cystic lesion in the right lobe of the liver and follow-up imaging revealed an increase in size and the percent solid component within the mass. In view of these changes, a nondiagnostic biopsy was obtained followed by extirpation of the lesion. Gross pathological review of the lesion identified a 9 × 9 × 7.5 cm, pink-yellow-tan, gelatinous mass, with a >1 cm clear surgical margin. Histologically, the mass consisted of benign dilated bile ducts, as well as myxoid stroma with spindle cells showing smooth muscle differentiation. The patient was discharged home on postoperative day five. A review of the literature for MHL in adults reports 30 previous cases, predominantly published as individual case reports describing the size, lobe(s) of the liver affected, and the cystic/solid nature of the tumor. MHL in adults may represent a potentially premalignant lesion, as the emerging literature supports a potential relationship between MHL and malignant undifferentiated embryonal sarcoma in regards to cytogenetic analysis. Aggressive surgical management of MHL in adults is mandated when feasible.

Imaging of paediatric liver tumours with pathological correlation

Paediatric hepatic tumours are relatively rare with malignant lesions being twice as frequent as benign neoplasms and are mostly metastases. Imaging has a significant role in the evaluation of most paediatric liver tumours. Differentiating benign from malignant tumours is important as it significantly affects treatment decisions. We present the characteristic radiological and pathological features of the most common paediatric liver tumours.

Giant mesenchymal hamartoma of the liver in an adult

We report a case of hepatic mesenchymal hamartoma in an adult; this condition is extremely rare, with only 15 cases having been reported in the English-language literature worldwide. The patient was a 36-year-old woman who was seen at her local hospital for upper abdominal distension. A giant multilocular cystic tumor, which had almost entirely replaced the normal parenchyma of the right lobe of the liver, was diagnosed. She was referred to our hospital, where, with a diagnosis of biliary cystadenoma, the tumor was successfully removed by right hemihepatectomy. After an uneventful postoperative course, the patient was discharged from our hospital. On histological examination, the tumor consisted of numerous cystic lesions without epithelial lining cells; hepatocytes, bile duct, and vascular components, without either lobular structure or atypia, were observed in the pseudocyst wall, leading to a diagnosis of hepatic mesenchymal hamartoma. There have been a few previously reported cases of multifocal hepatic mesenchymal hamartoma reappearing in the remaining liver after hepatectomy, although these cases are considered to be extremely rare. Therefore, periodic follow-up will be necessary for the patient.

Undifferentiated embryonal sarcoma of the liver: case report and literature survey

Undifferentiated embryonal sarcoma (UES) of the liver was first identified as an independent clinicopathologic type of sarcoma in 1978. It is an uncommon hepatic tumor, of mesenchymal origin, usually observed in children, and cases in adults are rare: to our best knowledge, reports of only 51 cases have been published in the past 50 years. We present a case of UES of the liver in a previously healthy 22 year-old woman, admitted to our hospital due to a palpable mass in the right upper abdomen. On admission, laboratory studies showed mildly elevated aspartate aminotransferase, alkaline phosphatase, and gamma-GPT. Hepatitis and tumor markers were negative. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) showed a large mass involving the right lobe and the medial segment of the liver, with compression of the bile duct. Right trisectionectomy with bile duct resection and reconstruction was performed. Microscopically, the tumor was composed of pleomorphic spindle cells in a myxoid stroma with focal staining of S-100 by immunohistochemistry. The histologic diagnosis was UES. Adjuvant therapy with vincristine, actinomycin-D, and cyclophosphamide was performed, and at 14 months of follow-up, the patient is alive without any evidence of recurrence. The clinical and histopathological features, as well as the therapeutic choices for adult UES, are described for this patient and in the literature of the past 50 years.

Pediatric liver: focal masses

Imaging is a standard part of the evaluation of pediatric liver disease. Advances in MR imaging have improved detection, characterization, and staging of hepatic lesions. This article addresses the MR imaging appearances of various focal hepatic lesions that can present in children. Techniques for performing hepatic MR imaging also are reviewed.

Pediatric liver tumors--a pictorial review

Hepatic masses constitute about 5-6% of all intra-abdominal masses in children. The majority of liver tumors in children are malignant; these malignant liver tumors constitute the third most common intra-abdominal malignancy in the pediatric age group after Wilms' tumor and neuroblastoma. Only about one third of the liver tumors are benign. A differential diagnosis of liver tumors in children can be obtained based on the age of the child, clinical information (in particular AFP) and imaging characteristics. The purpose of this review is to report typical clinical and imaging characteristics of benign and malignant primary liver tumors in children.

Hepatic mesenchymal hamartoma: cytogenetic analysis of a case and review of the literature

Hepatic mesenchymal hamartoma (HMH) is a rare benign liver tumor generally occurring in young children. Abnormalities of chromosome 19q13.4 and chromosomal aneuploidy detected by flow cytometry have been reported in HMH. We recently analyzed a HMH in a 14-month-old girl and identified additional novel chromosome abnormalities, including hypodiploidy with deletions of several chromosomes, without rearrangement of 19q13.4 on both routine chromosome analysis and fluorescent in-situ hybridization analysis using subtelomere probes for chromosome 19q. This case underscores the need for chromosome analysis of all HMH and the need to report these changes to better understand the pathophysiology and the entire spectrum of cytogenetics of this uncommon tumor.

Undifferentiated embryonal sarcoma of the liver in adults

BACKGROUND

Undifferentiated embryonal sarcoma of the liver (UESL), a rare tumor that predominantly affects children, generally has been considered an aggressive neoplasm with an unfavorable prognosis. More recent reports have indicated that modern multimodal treatment and supportive care improve the survival of children with UESL. Data regarding the treatment and survival of adults have not been reviewed comprehensively, and only a few adult patients with UESL have been reported in the literature.

METHODS

The authors analyzed demographics, treatment, and actuarial survival of all reported cases of UESL in patients aged >or=15 years (n = 67 patients). In addition, 1 case is presented of a patient with UESL who was treated successfully at the authors' institution.

RESULTS

The median survival of all patients with UESL who were analyzed was 29 months. Patients who underwent complete tumor resection followed by adjuvant chemotherapy survived over a median follow-up of 28.5 months and had significantly better survival compared with patients who underwent surgical treatment alone. Patients who underwent an incomplete tumor resection had a tendency toward poorer outcomes.

CONCLUSIONS

To the authors' knowledge, this is the first report to demonstrate a significant effect on survival for adjuvant chemotherapy after complete surgical resection of UESL in adults. The role of neoadjuvant chemotherapy was not evaluated in this study. In the case study presented herein, combined therapy with surgery and chemotherapy led to a complete, sustained remission that has lasted for >6 years to date.

Mesenchymal hamartoma of the liver mimicking hepatoblastoma

Mesenchymal hamartoma of the liver is a cystic benign liver mass occurring in children. Diagnostic confusion with hepatoblastoma may arise when alpha-feto-protein (AFP) level is elevated. We report an extremely rare case of mesenchymal hamartoma in an 11-month-old boy. Serum AFP was elevated and fine-needle aspiration biopsy suggested the lesion as hepatoblastoma, so he received preoperative chemotherapy. At the end of the preoperative chemotherapy, the tumor size and AFP level decreased. A right hepatectomy was performed. The pathologic examination of the specimen revealed mesenchymal hamartoma. Mesenchymal hamartoma of the liver with increased serum AFP levels may mimic hepatoblastoma if a cytological examination samples only the hepatocellular component of mesenchymal hamartoma. According to our knowledge, this is the first case of the mesenchymal hamartoma of the liver, which showed reduction in serum levels of AFP and involution of the tumor size by preoperative chemotherapy.

[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.