So-called extraskeletal Ewing's sarcoma. Report of a case with ultrastructural analysis

Primary extra-skeletal Ewing's sarcoma presenting as an epidural Soft Tissue Lesion causing cauda equina syndrome in an adolescent girl: a case report

INTRODUCTION

Primary epidural Ewing's sarcoma in the lumbar spinal canal is a rare condition and very few cases are reported in the literature.

CASE REPORT

A fifteen-year-old girl presented with low backache associated with sudden onset of weakness and radiculopathy of both lower limbs for 10 days, bowel and bladder involvement for 3 days. Physical examination revealed grade 0/5 power and absent sensations below L4 dermatomal level and perianal region (ASIA A). Plantar reflex was mute bilaterally. Magnetic resonance imaging revealed an extradural lesion within the spinal canal at the L3-L4 level. The patient underwent an emergency posterior decompression, extradural lesion excision and instrumented stabilization L3-L5. Based on histopathological examination of the tissue specimen, we diagnosed the lesion as Ewing sarcoma.

DISCUSSION

Primary extra-skeletal Ewing's sarcoma presenting as an epidural lesion in the lumbar spine is a rare clinical entity that should be considered as a differential for spinal epidural lesions. Treatment for such cases is almost always an early surgical intervention due to its rapid onset and compressive neurological symptoms. Wide decompression with instrumented fusion and excision of the lesion followed by chemo and radiotherapy are recommended.

Adult Primary Spinal Epidural Extraosseous Ewing's Sarcoma: A Case Report and Review of the Literature

Background. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare malignancy, especially in adults. Case Presentation. A 40-year-old male presented with back pain and urinary hesitancy. MRI revealed a thoracic extradural mass with no osseous involvement. He underwent surgery for gross total resection of the mass, which was diagnosed as Ewing's sarcoma. He was subsequently treated with chemoradiotherapy. He remains disease-free 1 year after surgery. Review of the literature indicated only 45 previously reported cases of spinal epidural extraosseous Ewing's sarcoma in adults. Conclusions. Extraosseous Ewing's sarcoma in the spinal epidural space is a rare clinical entity that should be included in the differential for spinal epidural masses. Its treatment is multidisciplinary but frequently requires surgical intervention due to compressive neurologic symptoms. Gross total resection appears to correlate with improved outcomes.

Primary spinal extradural Ewing's sarcoma (primitive neuroectodermal tumor): Report of a case and meta-analysis of the reported cases in the literature

Background:

Primary spinal primitive neuroectodermal tumors (PNET) and/or spinal extraskeletal Ewing's sarcoma family tumors (ESET) are rare lesions appearing in the spinal extradural space. One hundred forty-one primary spinal PNETs, including 29 intramedullary lesions, have been reported in the literature. Encountering a case of primary epidural EES/peripheral PNET (pPNET) in sacral level, which is the fifth one occurring at this level in the literature, we have tried to conduct a meta-analysis of the reported cases.

Case Description:

A 44-year-old lady with epidural EES/pPNET is reported here. She was once operated for L5/S1 herniated disc, which did not ameliorate her symptoms. The clinical, imaging, surgical, and histopathologic characteristics of our case are presented and wide search of the literature is also done. All the reports were level 3 or less evidences and most of the series had missing parts. 106 cases of primary intraspinal (extradural/extramedullary-intradural) EES/pPNET and 29 cases of primary intramedullary PNET (CNS-PNET) have been reported in the literature. The most common clinical presentation in both entities was muscle weakness proportionate to the tumor location. Distant metastasis occurred in 38 of 99 (38%) cases of primary intraspinal EES/pPNET, while the rate of metastasis was 48% in patients with PNETs occurring in the intramedullary region (P > 0.05). One-year survival rate of the patients who underwent chemo-radiation after total or subtotal resection was better than those who did not receive chemotherapy or radiotherapy, or did not have total or subtotal resection. However, this difference was not repeated in 2-year survival rate in any of the tumor groups.

Conclusion:

It seems that total or subtotal removal of the tumor and adjuvant chemo- and radiation therapy can improve the outcome in these patients.

Spinal epidural extraskeletal Ewing sarcoma

A rare case of extraskeletal Ewing sarcoma, arising primarily in the spinal epidural space is reported. An 18-year-old male presented with a 2-month history of right shoulder pain progressing to complete paraplegia and urinary retention over the course of 2 days. Magnetic resonance imaging demonstrated an extradural mass extending from the C6 to T1 level. Histopathologic examination confirmed the diagnosis. The literature is reviewed and radiological differential diagnosis of this rare neoplasm is briefly discussed.

Establishment and characterization of a clonal human extraskeletal Ewing's sarcoma cell line, EES1

Ewing's sarcoma, a small round cell sarcoma arising in soft tissue as well as the bone, is one of the most malignant tumors in children and young adults. Few established cell lines of extraskeletal Ewing's sarcoma (EES) have been reported, which made it difficult to examine the biological features of EES. Therefore, we have established a new clonal cell line of EES. We report its morphological characters, results of chromosomal and immunohistochemical analysis. A piece of tumor obtained from the 18-year-old female patient with EES was xenografted in a nude mouse. In vitro subcultured cells were then obtained from this xenograft. A clonal cell line was subsequently established by limiting dilution and designated EES1. EES1 cells had a doubling time of 24 hours. In the xenografted tumor, the cells expressed vimentin, CD99 (MIC2), neuron specific enolase (NSE) and cytokeratin. The original tumor cells also expressed vimentin, CD 99, and NSE, but was negative for cytokeratin. The morphological and immunohistochemical features of this cell line established, except for cytokeratin expression, were consistent with those of the primary tumor. Cytogenetic analysis of EES1 revealed chromosomal translocation of t(11; 12)(q24;ql2). The chimeric fusion of the Ewing's sarcoma gene in band 22q12 with the Friend leukemia virus integration-1 gene in band 11q24 was also demonstrated. Fluorescence in situ hybridization further confirmed the presence of translocation involving the Ewing's sarcoma gene in both the primary tumor and EES1 cells. In conclusion, we have established a human EES cell line EES1, which will provide a useful model for studying various aspects of human EES.

[Primary lumbar epidural Ewing's sarcoma: case report]

We report a case of a 15-years old female with an acute paraparesis secondary of an epidural mass and histopathological diagnosis was consistent with an Ewing's sarcoma without bone compromise. An exaustive literature review showed only 17 cases of primary lumbar epidural extraosseus Ewing's sarcoma.

Orbital Ewing's sarcoma of the orbit

PURPOSE

Ewing's tumor is a primary tumor of bone in childhood that only rarely involves the orbit. Most such cases are metastatic from distant sites. This tumor may be confused with other small round cell malignancies of childhood, and immunohistochemical studies are essential in making the diagnosis.

METHODS

We present two cases of Ewing's tumor of the orbit. One was in a 22-year-old boy with an occult primary tumor in the frontal bone that became symptomatic after forehead trauma. The other example was in a 7-year-old boy with a known Ewing's primary of the clavicle. The clinical manifestations and diagnostic criteria are discussed.

RESULTS

In most cases with orbital involvement, ophthalmic symptoms consist of proptosis, pain, and occasionally visual loss and motility restriction. The diagnosis is typically unsuspected before histologic evaluation. Electron microscopic and immunohistochemical analyses are essential in making the diagnosis and are necessary for all such small round cell tumors.

CONCLUSIONS

Ewing's sarcoma is a rare orbital tumor of bone mainly affecting children. Local treatment relying on surgical extirpation and radiotherapy alone has proven inadequate, with 5-year survival rates of <10%. The addition of chemotherapy has improved survival rates significantly to approximately 50%.

Primary spinal epidural extraosseous Ewing's sarcoma

The case of a 7-year-old boy with a spinal epidural extraosseous Ewing's sarcoma (EES) is presented. He is in complete remission without neurologic deficit 40 months after diagnosis. Another 15 cases were found in the literature and are discussed together with this patient. Twelve of them were male patients. The mean age of the patients was 17.5 years (range, 4 to 47). Symptoms included back pain and/or radicular pain (100%), paresis of one or both legs (83%), sensory disturbances, and bladder and bowel dysfunction. The mean diagnostic delay was 5.8 months. Each patient underwent laminectomy; complete resection of the tumor was impossible in more than 50% of the cases. Most patients received radiation therapy and/or chemotherapy. Four patients suffered from local recurrence, eight from metastases. Ten (63%) patients died, 1 to 48 months (mean, 16) after diagnosis. The differential diagnosis is discussed, including disk herniation and several benign and malignant tumors.

Soft tissue Ewing's sarcoma. Characterization in established cultures and xenografts with evidence of a neuroectodermic phenotype

This study characterizes the histogenesis of soft tissue Ewing's sarcoma (StEs) based upon an analysis of three tumors. Long-term cultured cell lines and nude mice xenografts were established from original neoplasms or from their metastases. Histologically they revealed a small round cell pattern without signs of differentiation. Several ultrastructural features of neural type were found; the same were also seen on culture cell lines. Moreover, immunohistochemical study for neural markers revealed the presence of HNK-1, NSE, LIRC-LON 36, S-100 protein, glial fibrillary acidic protein, neurofilaments (70 kilodaltons), and chromogranin; some of these markers were present only in the transplants. Cytokeratin was also seen. The translocation t(11;22)(q24;q12) was found in all three neoplasms together with other chromosomal abnormalities. N-myc RNA gave negative results whereas c-myc RNA was expressed. Therefore it may be postulated that StEs displays neuroectodermal features somewhat similar to those seen in peripheral neuroepithelioma as well as in atypical Ewing's sarcoma of bone.

Radiological features of extraskeletal Ewing sarcoma

The radiological features of extraskeletal Ewing sarcoma were reviewed in 22 patients whose average age was 22 years. Tumours were located in the extremities (11 patients), abdomen or pelvis (six patients) and the chest (five patients). The tumours ranged in size from 2 cm to 20 cm, were mainly well circumscribed and showed no evidence of calcification prior to treatment. Most tumours (13 out of 14) were of low attenuation or contained areas of lower attenuation than muscle on computed tomographic examination, and in six out of seven patients studied by ultrasound the tumours were hypoechoic or partly anechoic. No distinctive post-contrast medium enhancement pattern on CT examination (11 patients) or angiographic features (three patients) were evident. Tumour haemorrhage was a frequent microscopic finding and changes consistent with this were present in one patient on magnetic resonance imaging examination. Distant metastases or local recurrence developed in 13 patients with lung being the most frequent metastatic site (eight patients). Although its radiological features are non-specific, extraskeletal Ewing sarcoma should be included in the differential diagnosis of noncalcified soft-tissue tumours especially in a young age group and where located in an extremity or paravertebral region of the chest.

Extraosseous Ewing's sarcoma. A study of 42 cases

Fifty patients at the Mayo Clinic (Rochester, MN) from 1935 to 1985 met the histologic criteria for extraosseous Ewing's sarcoma. Forty-two had soft tissue primaries without bony involvement and formed the basis for this retrospective study of the clinical behavior and management of extraosseous Ewing's sarcoma. There were 19 male and 23 female patients (mean age, 22 years). Metastases were documented in 30 of the patients, six at the time of presentation and 24 occurring up to 11 years later, most commonly to lungs or bone. Three patients were lost to follow-up. Sixteen of 35 patients (46%) had local recurrence. Overall survival was 15 of 39 (38.5%) at 5 years. Decreased survival was noted with pelvic tumors, incomplete resections, and presence of metastatic disease, whereas increased survival was associated with wide surgical resection with negative microscopic margins, adjuvant local radiation therapy, and presentation since 1970 (48% 5-year survival compared with 28% before 1970).

Primary peripheral neuroepithelioma of the orbit with intracranial extension

A 7-year-old girl with clinical signs limited to moderate unilateral proptosis of 2 weeks duration and ipsilateral disc edema was found to have a contiguous orbital and subfrontal intracranial tumor best characterized as a peripheral neuroepithelioma by recent studies. Previously this tumor would have been called an extraosseous Ewing's sarcoma. The tumor had a significant lobular component on either side of the orbital roof. The patient is still alive 24 months posttreatment with multimodal excisional surgery, radiation, and chemotherapy.

Extraskeletal Ewing's sarcoma

A well documented case of extraskeletal Ewing's sarcoma arising in a finger of a 16-year-old man was studied by light microscopy, immunohistochemistry and electron microscopy. The differential diagnoses of similar "round cell neoplasms" are discussed. Emphasis is placed on the distinction between extraskeletal Ewing's sarcoma and peripheral neuroepithelioma.

Extraosseous Ewing's sarcoma versus primitive rhabdomyosarcoma: diagnostic criteria and clinical correlation

A light and electron microscopic study of 51 cases of Ewing's sarcoma of bone (ESB) and 33 soft tissue sarcomas (carrying a variety of light microscopic diagnoses, including primitive rhabdomyosarcoma) in children and young adults was performed to clarify the similarities and differences among these tumors. Ultrastructural criteria were developed to evaluate the neoplasms. Remarkable ultrastructural uniformity was found in the cases of ESB. In contrast, the soft tissue sarcomas could be divided into two distinct groups on the basis of the ultrastructural criteria: those closely resembling primitive areas of otherwise differentiated rhabdomyosarcomas, and those indistinguishable from ESB. It is proposed that the diagnosis of soft tissue Ewing's sarcoma be reserved for lesions identical to ESB by both light and electron microscopy. The first group of sarcomas may be histogenetically related to rhabdomyosarcoma and should be distinguished from extraosseous Ewing's sarcoma, as their clinical behavior appears to be quite different.

A unified hypothesis for the histogenesis of the soft tissue sarcomas of unknown origin

At the present time there is still a group of soft tissue sarcomas with an unknown origin. These occur most frequently in the extremities and include the following sarcomas: clear cell, alveolar, synovial, epithelioid, chordoid and small round cell. Most of the studies directed to find their histogenesis are based on finding similarities between normal embryonic or mature tissues of the tenosynovial region and these tumors at the ultrastructural and immunohistochemical level searching for specific markers. In this sense, the results are confusing and the common or different cells responsible for these sarcomas have not yet been isolated. In the present hypothesis it is proposed that the common progenitor of these malignancies is an ectomesenchymal derived tissue related to the tendons, aponeuroses, synovia and menisci called chondroid tissue or pseudocartilage; the evolutionary reasons that support this hypothesis are also discussed here. This also emphasizes the possibility that these sarcomas originate in phylogenetic mature remains and not in the reactivation of embryological cellular groups (Cohnheim's theory).

Extraskeletal Ewing's sarcoma: a clinical, morphological and ultrastructural analysis of five cases with a review of the literature

In 1969 it was recognised that tumors with light microscopic appearances indistinguishable from Ewing's sarcoma of bone may arise in extraskeletal sites (extraskeletal Ewing's sarcoma). Here, we review the available literature and report five new cases. All five received combined modality therapy with combination chemotherapy and radiotherapy to the primary site followed by surgical excision in two. All attained complete remission; after a median follow-up of 26 months, three remain disease-free but two have relapsed and died. Our experience, in accord with previous series, suggests that extraskeletal Ewing's sarcoma compared with its bony counterpart tends to occur in older subjects, has a similar incidence in males and females, usually presents with a painless mass and readily responds to combined modality therapy. We detected no light or electron microscopic features to denote a histogenetic origin. However, we suspect extraskeletal Ewing's sarcoma may occur more frequently than previously supposed.

Extraskeletal Ewing's sarcoma with cutaneous involvement

We report the case of a 13-year-old girl with extraskeletal Ewing's sarcoma involving the skin and subcutaneous tissue of the upper back. The patient underwent wide local excision and right axillary node dissection, and received chemotherapy with vincristine, actinomycin D, and cyclophosphamide. There was no evidence of recurrence or metastasis in eight months of follow up. Light and electron microscopic features were typical for this neoplasm. Tumor cells contained abundant glycogen, but failed to stain for desmin, keratin, neuron-specific enolase, or S-100 protein. We discuss the differential diagnosis of extraskeletal Ewing's sarcoma as well as theories of its histogenesis.

Cutaneous extraskeletal Ewing's sarcoma

Extraskeletal Ewing's sarcoma has been recognized as being histologically indistinguishable from Ewing's sarcoma of bone. Although the occurrence of extraosseous Ewing's sarcoma in deep soft tissues has been well described, such cutaneous lesions are rare. We report the clinical history, histopathologic findings, and results of ultrastructural study of this rare variant occurring in a 12-year-old girl. She presented with a dermal and subcutaneous tumor of the left third toe, without osseous involvement. The lesion was composed of masses of round-oval cells, with perilobular fibrosis, focal hemorrhage, ill-defined pale cytoplasm containing glycogen, and absent pericellular reticulin. Ultrastructural study showed a monotonous cell population, with focal thickening of apposing membranes, high nuclear/cytoplasmic ratio, copious intracytoplasmic glycogen, and paucity of organelles except mitochondria. We present this case along with discussion of the literature and problems concerning differential diagnosis of small cell malignancies in the skin.

On the histogenesis of Ewing's sarcoma. An ultrastructural, immunohistochemical, and cytochemical study

Forty-two cases of Ewing's sarcoma (ES) have been studied with light microscopy during the 9-year period 1974 to 1982. Thirty-three patients had ES of bone, and in 9 patients the tumor was located in the extraskeletal soft tissues. Cases which fulfilled all the morphologic criteria were accepted as typical ES (31 cases), and those with some architectural or cytologic peculiarities were considered atypical forms of ES (11 cases). An immunohistochemical study (PAP method) to evaluate the presence in the tumor cells of the following markers: myoglobin, F-VIII-related antigen, lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and immunoglobulins (IgG, IgA, IgM, kappa and lambda light chains), was performed with negative results in all cases (paraffin blocks were available in 38 cases). The cytochemical study on fresh tissue imprints from five patients (PAS, Sudan Black, alpha-naphthyl acetate esterase, acid phosphatase, beta glucuronidase, myeloperoxidases, naphthol-AS-D chloroacetate esterase and alkaline phosphatase) gave no pattern of histogenetic significance, PAS being the best morphologic marker in tissue sections and touch preparations. A detailed ultrastructural study was performed on 34 cases; the main findings may be summarized as follows: medium sized cells, polygonal shape, oval nuclei, smooth nuclear envelope, abundant euchromatin, well-developed nucleolonema, scant membranous organelles, abundant hyaloplasmic glycogen, occasional lipid vacuoles, straight cell membranes, and primitive intercellular junctions. No differences were found between bone and extraskeletal ES; moreover, typical and atypical forms showed moderate quantitative differences with no qualitative change. The histogenesis is discussed; no functional or morphologic markers have been found to suggest the cell of origin; however, some cell lines may be excluded. It is the impression of the authors that they are dealing with a primitive noncommitted mesenchymal cell.

Neuroblastoma and the differential diagnosis of small-, round-, blue-cell tumors

Of the solid tumors of childhood, neuroblastoma--the prototypic small-, round-, blue-cell neoplasm--occurs in the youngest patients and has shown the least predictable biologic behavior and response to therapy. It is often confused clinically and histologically with Wilms' tumor, rhabdomyosarcoma, lymphoma, and especially, Ewing's sarcoma. Certain clinical and histologic features that may be useful in prognosis have been identified, however, and a variety of distinctive light microscopic, electron microscopic, and immunohistochemical features may be useful in differentiating this and related tumors. Many of the varied techniques useful in the differential diagnosis of these tumors can now be employed routinely in most laboratories.

Extraskeletal Ewings sarcoma

A case of Ewings sarcoma arising in the soft tissue of the thumb is described. This appears to be the first case of digital extraskeletal Ewings sarcoma. The soft tissue location, the primary rather than metastatic nature, and the tumor type in this case were well documented.

Extraskeletal Ewing sarcoma with computed tomography correlation

Extraosseous Ewing sarcoma--a rare clinical entity--is described and the radiographic and histologic features discussed. Histologically this type of tumor may be differentiated from other soft tissue malignancies, but the ultrastructural glycogen content of the cytoplasm makes it frequently inseparable from the conventional osseous form of Ewing sarcoma. In spite of the presence of a huge paraosseal mass with bone erosion or periosteal new bone, computed tomography was the only preoperative modality able to provide evidence of non-involvement of the marrow cavity. However, histologic documentation is necessary to prove that one is dealing with a totally extraosseous Ewing sarcoma.

Ultrastructural, biochemical, and cell-culture studies of a presumed extraskeletal Ewing's sarcoma with special reference to differential diagnosis from neuroblastoma

The history of a 6-year-old girl with a tumor originating from thoracic spine and finally becoming resistant to surgery, radio-, and chemotherapy is reported. Tumor-biopsy material was studied by light and electron microscopy, in cell culture, by acetylcholinesterase ultracytochemistry, and by quantitative catecholamine analysis and this led to the rejection of the initial diagnosis of a neuroblastoma. Light microscopy revealed a uniform population of undifferentiated cells incompletely lobulated by broad fibrovascular septa. Using the electron microscope, cells were characterized by large intracellular pools of glycogen, little cytoplasm with an abundance of free ribosomes and a paucity of organelles. A few cells displayed desmosome-like attachment sites. Staining for specific and unspecific acetylcholinesterase was negative with light and electron microscopy, as were the results of catecholamine histofluorescence using the glyoxylic acid method. The latter result was confirmed by the negative outcome of quantitative analyses of dopamine, noradrenaline, and adrenaline with high pressure liquid chromatography nd electrochemical detection in tissue samples. Tumor cells could easily be maintained in culture for up to 4 weeks. None of a variety of treatments that are known to favor expression of neuronal characteristics in neuroblastoma cells (serum withdrawal, nerve growth factor, dbcAMP, dexamethasone) induced morphological differentiation in cultured tumor cells. On the basis of the clinical history, morphology, and of our experiments with tumor cells, the diagnosis of a so-called extraskeletal Ewing's sarcoma is most likely. Our results strengthen the view that a cell biology approach may be valuable in neuroblastoma differential diagnosis.

Ewing's sarcoma with neuroblastoma-like features

Four tumors with the clinical and light microscopic features of Ewing's sarcoma contained cells that possessed to varying degrees ultrastructural features suggestive of neuroblastoma. These neoplasms were considered to be Ewing's sarcoma of bone by radiologic examination and on clinical grounds, and light microscopy was consistent with the diagnosis in every case. It is suggested that the ultrastructural morphology of Ewing's sarcoma is broader than had been supposed and that the presence of dendritic processes in a small cell tumor of bone should not exclude the diagnosis of Ewing's sarcoma.

Collateral venous flow through uterus caused by retroperitoneal extraosseous Ewing sarcoma

We report on a twenty-four-year-old woman with extraosseous Ewing sarcoma in the right retroperitoneum. The tumor blocked the common iliac vein, and because of an intervening pregnancy, the blood flow was shunted through the uterus and left ovarian vein back into the vena cava. She died within nine months despite radical surgery, radiotherapy, and chemotherapy.

Lumbar epidural Ewing sarcoma. Light and electron microscopic investigation

The clinicopathological findings in a child with extraskeletal Ewing sarcoma are described. The patient complained of pain in the lower back and difficulty walking. An extraskeletal, epidural, friable tumor, 2-3 cm long was removed from the epidural space. It had no relationship with the bone structures. Light and electron microscopic examination of the tumor led to the diagnosis of Ewing sarcoma. The morphological aspects of this neoplasia and the problem of the differential diagnosis with other small cell tumors of the epidural space are discussed.