Extraskeletal Ewing's sarcoma of the nose

A 20-year-old woman presented with nasal obstruction and slight epistaxis. The obstructing lesion was excised and microscopy showed a neoplasm composed of comparatively uniform undifferentiated cells forming solid nests. The cytoplasm of the cells was clear but poorly demarcated, partly vacuolated and contained much glycogen. Although widespread in the nasal mucosa, the cells did not penetrate into the underlying bone. The cells expressed the MIC2 gene (using the CD99 marker). Electron microscopy showed simple cells with a small number of mitochondria, many glycogen particles; there were no neurosecretory granules present. Early surgical treatment followed by chemo- and radiotherapy have greatly improved the prognosis of EWS: extraskeletal Ewing's sarcoma (EWS/PNET).

Immunohistochemical detection of FLI-1 protein expression: a study of 132 round cell tumors with emphasis on CD99-positive mimics of Ewing's sarcoma/primitive neuroectodermal tumor

The histologic and immunohistochemical differentiation of Ewing' s sarcoma/primitive neuroectodermal tumor (ES/PNET) from other small, blue, round cell tumors may be difficult. Despite initial promise, CD99 (MIC2) has not proven to be a specific marker. Approximately 90% of ES/PNET have a specific t(11; 22)(q24;q12) that results in fusion of the EWS and FLI-1 genes, and overexpression of FLI-1 protein. A recent study has shown immunohistochemical FLI-1 expression in five of seven of the ES/PNET cases tested. We evaluated FLI-1 expression in 132 well-characterized small, blue, round cell tumors. All tumors were immunostained for FLI-1 (1:40, Sc 356 polyclonal, Santa Cruz Biotechnology) using steam heat for epitope retrieval. Only nuclear staining was accepted as positive. Endothelial cells were strongly positive in all cases and served as an internal control. In many cases, a subset of lymphocytes also stained positive. No staining was seen in any other normal tissue. FLI-1 expression was seen in 29 of 41 (71%) ES/PNET, 7 of 8 (88%) lymphoblastic lymphomas, 0 of 8 poorly differentiated synovial sarcomas (PDSS), 0 of 32 rhabdomyosarcoma (RMS), 0 of 30 neuroblastomas, 0 of 8 esthesioneuroblastomas, 0 of 3 Wilms' tumors, 0 of 1 mesenchymal chondrosarcoma, and in 1 of 1 desmoplastic round cell tumor. This last case was known to have an EWS/WT-1 fusion. Although the EWS/FLI-1 fusion gene is specific for ES/PNET, FLI-1 protein expression is not. Significantly, the great majority of lymphoblastic lymphomas (also CD99-positive) are strongly FLI-1-positive. Immunohistochemical detection of FLI-1 may be valuable in confirming the diagnosis of ES/ PNET in cases in which molecular genetic evaluation is not feasible. FLI-1 protein expression is also helpful in distinguishing ES/PNET from other tumors that may be CD99-positive, such as PDSS and RMS. It is not surprising that some ES/ PNET are FLI-1-negative, because not all ES/PNET have the classic EWS/FLI-1, and some cases of ES/PNET may produce either low levels of protein or idiotypically different protein.

[Detection of minimal residual disease in Ewing's sarcoma using RT-PCR]

BACKGROUND

More than 90% of Ewing's sarcomas (ES) contain a fusion of the EWS and FLI-1 genes, due to the t(11;22)(q23;q12) translocation. At the molecular level, the EWS-FLI-1 rearrangement shows great diversity. Specifically, many different combinations of exons from EWS-FLI-1 encode in-frame fusion transcripts and result in differences in length and composition of the chimeric protein, which function as an oncogenic aberrant transcription factor. The finding of this translocation gives evidence for the presence of ES cells. The aim of this prospective study was to verify applicability of the RT-PCR method for the detection of minimal residual disease in patients with ES.

METHODS AND RESULTS

Conditions for the detection of Ewing's sarcoma cells by means of the reverse-transcriptase polymerase chain reaction (RT-PCR) at fusion transcripts in peripheral blood, bone marrow (BM) and autologous hematopoietic stem cell grafts in patients with ES were appointed. 31 samples of BM, 5 samples of blood and 7 peripheral blood grafts obtained from 23 patients were investigated. Presence of tumor cells was identified in 7 BM samples from 7 different patients (31 samples from 16 patients), all the peripheral blood and graft samples were negative.

CONCLUSIONS

The high sensitivity of RT-PCR method in detection of cells bearing t(11;22)(q23;q12) was demonstrated in the experimental model and clinical samples. Likewise the literary statements, the RT-PCR method was found to be more sensitive than cytology.

Malignant round cell tumours of bone: atypical clinical and imaging features

OBJECTIVE

To describe the clinical, radiological and MRI features of six atypical cases of histologically proven appendicular Ewing sarcoma/primitive neuroectodermal tumour (PNET).

DESIGN

Retrospective review of case notes and available imaging was carried out.

PATIENTS

Six patients (4 male, 2 female; mean age 27 years, range 19-44 years), presenting over a 77-month period, were identified from the Bone Tumour Register. All had unusual clinical and imaging features for Ewing sarcoma/PNET.

RESULTS AND CONCLUSIONS

Four tumours were centred on the distal femoral metaphysis, one in the proximal tibial metaphysis and one in the distal tibial metaphysis. Plain radiographs were available in four cases and showed minor cortical changes. MRI demonstrated a relatively small, eccentrically located intraosseous component with a large, eccentric extraosseous component. Extension into the epiphysis was seen in three cases and into the adjacent joint in two cases. Intraosseous "skip" metastases were present in three cases. The clinical and imaging features were atypical for conventional intraosseous Ewing sarcoma/PNET and the exact site of origin (intraosseous, periosteal or soft-tissue) was unclear.

Numb chin syndrome in Ewing sarcoma

The numb chin syndrome consists of unilateral hypesthesia of the chin and lower lip. In adults, it is often associated with metastatic disease to the mandible, base of the skull, or leptomeninges. In children, it has been associated with infiltration of the inferior alveolar nerve by leukemic cells. We describe two cases of numb chin syndrome in children with Ewing sarcoma. In a child with a solid tumor, this symptom seems to have an ominous meaning and should lead to the investigation of progressive skeletal involvement.

[A case of extraskeletal Ewing's sarcoma of the thoracic wall]

The Authors report a case of extraskeletal Ewing's sarcoma of thoracic wall in a 15-year-old sport-man, who complained about pain in the left upper extremity. The diagnosis was performed by radiology (ultrasound study, TC, RM) and pre-operative needle-aspiration biopsy. The patient was treated by neoadjuvant chemotherapy, wide surgical resection and, then, radiotherapy. Neither local recurrence nor metastases have developed for 8 months.

WT1 staining reliably differentiates desmoplastic small round cell tumor from Ewing sarcoma/primitive neuroectodermal tumor. An immunohistochemical and molecular diagnostic study

Differentiating desmoplastic small round cell tumor (DSRCT) from another similar small round cell tumor of childhood, the Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET), can be difficult because morphologic and immunohistochemical features overlap. We studied the predictive value of immunohistochemistry with an antibody to the C-terminal region of the Wilms tumor (WT1) protein for differentiating DSRCT from EWS/PNET in 24 malignant small round cell tumors that had been previously diagnosed as DSRCT or EWS/PNET by standard methods. We performed reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in cases with available tissue as a confirmatory measure: 6 of 13 DSRCTs were informative by RT-PCR, and 6 of 6 showed an EWS-WT1 fusion; all 13 DSRCTs showed strong, definitive nuclear staining with the WT1 antibody. All 11 EWS/PNETs were WT1 antibody negative; 7 of 11 cases classified as EWS/PNET were informative by RT-PCR, and 7 of 7 showed an EWS-FLI-1 fusion. For cases in which the morphologic and immunohistochemical features are consistent with a diagnosis of DSRCT, WT1 antibody staining predicts the EWS-WT1 translocation with high sensitivity and specificity and is, therefore, useful for differentiating DSRCT from EWS/PNET when genetic information is unavailable.

Prognostic impact of INK4A deletion in Ewing sarcoma

BACKGROUND

The primary genetic alteration in > 95% of Ewing sarcomas (ES) is a specific fusion of EWS with FLI1 or ERG. Secondary genetic alterations possibly involved in progression of ES are not well understood. A recent study found loss of the negative cell cycle regulator gene INK4A in 8 of 27 ES samples (30%). To confirm these findings and evaluate their prognostic significance, the authors studied INK4A deletion in 41 ES samples from 39 patients.

METHODS

Using Southern blot analysis with an INK4A p16 cDNA probe, the intensity of the INK4A bands in ES DNA samples was normalized to that of a control probe and compared with nondeleted control DNA; > 50% signal reduction was scored as evidence of deletion. All ES tumor DNA samples previously were confirmed to have EWS rearrangements on the same Southern blots, using a cDNA probe spanning the EWS breakpoint region.

RESULTS

Tumors from 7 patients (18%) showed INK4A deletion independent of disease stage (localized or metastatic) or sample source (primary tumor or metastasis). INK4A was a strong negative factor for disease specific survival in univariate analysis (P = 0.001) and in multivariate analysis including stage (relative risk = 6; P = 0.001).

CONCLUSIONS

INK4A deletions appear to be the most frequent secondary molecular genetic alteration found to date in ES. Their possible clinical usefulness in identifying a subset of ES patients with poor prognosis merits systematic prospective analysis. [See related article on pages 783-92.]

Immunohistochemistry of small round-cell tumors

The term "small round-cell tumor" describes a group of highly aggressive malignant tumors composed of relatively small and monotonous undifferentiated cells with high nuclear to cytoplasmic ratios. This group includes Ewing's sarcoma (ES), peripheral neuroepithelioma (aka, primitive neuroectodermal tumor or extraskeletal ES), peripheral neuroblastoma ("classic-type"), rhabdomyosarcoma, desmoplastic small round-cell tumor, lymphoma, leukemia, small-cell osteosarcoma, small-cell carcinoma (either undifferentiated or neuroendocrine), olfactory neuroblastoma, cutaneous neuroendocrine carcinoma (aka, Merkel-cell carcinoma), small-cell melanoma, and mesenchymal chondrosarcoma. Their clinical presentations often overlap, thus making a definitive diagnosis problematic in some cases. Yet, a clear understanding of their clinicopathologic features usually allows for a confident diagnosis, especially if immunohistochemistry is used. The following is a review of the immunohistochemistry of this small round-cell tumor group.

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%.

[Follow-up of patients with osteosarcoma and Ewing's sarcoma: a retrospective cost-benefit analysis]

PURPOSE

Determination of the respective roles of clinical investigation, laboratory tests and various imaging techniques in the follow up of children and adolescents with osteosarcoma and Ewing's sarcoma.

METHODS

In a retrospective monocenter analysis, charts of 72 patients with osteosarcoma and 47 patients with Ewing's sarcoma were reviewed with respect to ability of different diagnostic methods to detect the relapse, and correlated outcome.

RESULTS

In about 25% of relapses, a second remission could be achieved. The most sensitive methods to detect a potentially curable relapse were clinical investigations and chest x-ray in the case of osteosarcoma and chest x-ray and whole body scintigraphy in the case of Ewing's sarcoma.

CONCLUSIONS

The different value of diagnostic methods in the follow-up of the two illnesses may be explained by the different tumor biologies and by distinct therapeutic strategies for the treatment of relapses in the two tumor entities. However, an ongoing evaluation of current follow-up strategies is necessary to take into account new therapeutic developments which may shift the importance of certain imaging techniques.

Incidence of occult cancer in children presenting with musculoskeletal symptoms: a 10-year survey in a pediatric rheumatology unit

OBJECTIVES

To assess the frequency and types of cancer found in children presenting to our Unit with musculoskeletal symptoms over a 10-year period.

METHODS

The medical records of patients with musculoskeletal symptoms and a final diagnosis of cancer were reviewed. In each case age, gender, presenting symptoms, laboratory data, diagnostic procedures, provisional and final diagnoses, and time between clinical onset and correct diagnosis were reviewed.

RESULTS

An underlying neoplasia was found in 10 of 1,254 patients (<1%) complaining of musculoskeletal symptoms. The types of malignancies found included acute lymphocytic leukemia (ALL) (6 cases), lymphoma (2 cases), neuroblastoma (1 case), and Ewing's sarcoma (1 case). The mean time between disease onset and final diagnosis was 3.2 months. The most common presenting feature was monoarthritis, involving the larger joints such as the elbows, knees or ankles. Juvenile idiopathic arthritis (JIA) was the most frequent provisional diagnosis. In the preliminary hematologic evaluation, eight patients had an increased erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) value. White blood cell (WBC) count was normal in almost all children, with a normal differential count. Lactic dehydrogenase (LDH) was raised in all children. Bone marrow aspirates and lymph node or bone biopsies were necessary to reach the final diagnosis.

CONCLUSIONS

A malignancy should always be excluded in children with musculoskeletal symptoms, especially when the clinical pattern is not characteristic of a specific rheumatic disease. Routine laboratory tests may be misleading. The simultaneous presence of high LDH or alpha-hydroxybutyric dehydrogenase (alpha-HBDH) levels and raised ESR or CRP, even with normal blood cell counts, should lead to additional investigations.

RELEVANCE

All patients presenting with arthritis or other musculoskeletal symptoms should have a thorough clinical examination. Disproportionate pain levels and an atypical pattern of "arthritis," especially in the presence of systemic manifestations, suggest a possible underlying malignancy.

Detection of areas with viable remnant tumor in postchemotherapy patients with Ewing's sarcoma by dynamic contrast-enhanced MRI using pharmacokinetic modeling

An approach is presented for monitoring the effects of neoadjuvant chemotherapy in patients with Ewing's sarcoma using dynamic contrast-enhanced perfusion magnetic resonance (MR) images. For that purpose, we modify the three-compartment pharmacokinetic permeability model introduced by Tofts et al. (Magn Reson Med 1991;17:357-67) to a two-compartment model. Perfusion MR images acquired using an intravenous injection with Gadolinium (Gd-DTPA) are analyzed with this two-compartment pharmacokinetic model as well as the with an extended pharmacokinetic model that includes the (local) arrival time t(0) of the tracer as an endogenous (estimated) parameter. For each MR section, a wash-in parameter associated with each voxel is estimated twice by fitting each of the two pharmacokinetic models to the dynamic MR signal. A comparison of the two wash-in parametric images (global versus local arrival time) with matched histologic macroslices demonstrates a good correspondence between areas with viable remnant tumor and a high wash-in rate. This can be explained by the high number and permeability of the (leaking) capillaries in viable tumor tissue. The novel pharmacokinetic model based on a local arrival time of tracer results in the best fit of the wash-in rate, the most important factor discerning viable from nonviable tumor components. However, parameter estimates obtained with this model are also more sensitive to noise in the MR signal. The novel pharmacokinetic model resulted in a sensitivity between 0.22 and 0.60 and a specificity between 0.61 and 1. The model based on a global arrival time gave sensitivities between 0.33 and 0.77 and specificities between 0.58 and 0.99. Both statistics are computed as the fraction of correctly labeled voxels (viable or nonviable tumor) within a specified ROI, which delineates the tumor. We conclude that the added value of estimating the local arrival time of tracer first manifests itself for moderate noise levels in the MR signal. The novel pharmacokinetic model should moreover be preferred when pharmacokinetic modeling is applied on the average signal intensity within a ROI, where noise has less effect on the fitted parameters.

Ewing's sarcoma of the facial zygomatic area bones in a young child: a case presentation

We present the case of a young patient with Ewing's sarcoma of the facial zygomatic area bones. This type of tumor in a very young child is a rare event and poses significant diagnostic and therapeutic challenges for the attending physician. In this case, the diagnosis was made by a computed tomography scan with subsequent histological confirmation. The differential diagnoses and therapeutic options are discussed.

Fine needle aspiration cytology of the Ewing's sarcoma family of tumors

OBJECTIVE

To study the cytomorphologic features of the Ewing's sarcoma (ES) family of tumors.

STUDY DESIGN

During a period of eight years (1990-1997), 123 soft tissue tumors and 65 bone tumors were evaluated by fine needle aspiration cytology (FNAC); 14 cases were diagnosed as in the ES family of tumors. The ages of the patients ranged from 8 to 30 years. All the cases were histologically confirmed.

RESULTS

Of 14 cases of the ES family of tumors, 7 were ES, 3 extraosseous ES (EOE), 2 peripheral primitive neuroectodermal tumor (PPNET) and 2 Askin tumor. Cytologically, smears from all the cases showed round tumor cells with a high nuclear/cytoplasmic ratio. On detailed examination, subtle differentiating features were observed. The cells in ES had finer nuclear chromatin in comparison to those of PPNET and Askin tumor, and punched-out clear cytoplasmic vacuoles were present. PPNET showed nuclear molding, unipolar cytoplasmic tags and Homer-Wright rosettes. Histologically, all cases of ES and EOE and one case of Askin tumor showed periodic acid-Schiff-positive inclusions.

CONCLUSION

FNAC features coupled with clinical findings enable a rapid diagnosis of the ES family of tumors, from which treatment modalities can be determined.

Ewing's family of tumors involving structures related to the central nervous system: a review

This review consolidates information gleaned from several case reports and larger series on Ewing's sarcoma family of tumors (EFT) involving structures related to and found in the central nervous system (CNS). These tumors involve the skull, the spinal column, adjacent soft tissues, the meninges, and the brain. We have separated the cases by skull region and spinal column level, and we discuss the attendant differences in prognosis following treatment by neurosurgery, radiation, and chemotherapy. Light and electron microscopic features can be used to differentiate EFT from other small round blue cell tumors that involve the CNS (central primitive neuroectodermal tumor, lymphoma, etc.). Recent molecular and genetic findings in EFT provide new diagnostic methods. We conclude that EFT involving the CNS and adjacent structures is not so rare as previously stated and that the prognosis is more favorable, as a rule, than for the more common examples arising in the long bones and pelvis.

Initial symptoms and clinical features in osteosarcoma and Ewing sarcoma

BACKGROUND

The time between the initial symptoms of osteosarcoma and Ewing sarcoma and the correct diagnosis and treatment is long. Over the last two decades, the prognosis for patients with these diseases has dramatically improved due to a new chemotherapy regimen. As a consequence, a limb-sparing operation has become an alternative to amputation. The aim of this study was to establish the initial symptoms and physical signs of osteosarcoma and Ewing sarcoma from the records of the first medical visit and to identify early characteristics of the diseases to shorten the delay to diagnosis.

METHODS

A group of patients with osteosarcoma or Ewing sarcoma was identified from the Swedish Cancer Register of patients thirty years old and younger. Records from the first medical visit due to symptoms related to the bone tumor were obtained for 102 patients with osteosarcoma and forty-seven patients with Ewing sarcoma.

RESULTS

Pain related to strain was reported by eighty-seven (85 percent) of the patients with osteosarcoma and thirty (64 percent) of those with Ewing sarcoma, but only twenty-one (21 percent) of the patients with osteosarcoma and nine (19 percent) of those with Ewing sarcoma reported pain at night. Forty-eight (47 percent) of the patients with osteosarcoma and twelve (26 percent) of those with Ewing sarcoma related the onset of symptoms to minor trauma occurring around the same time. A palpable mass was noted in forty (39 percent) of the patients with osteosarcoma and sixteen (34 percent) of those with Ewing sarcoma at the first visit, and in most cases the tumor diagnosis was suspected. There was a broad spectrum of misdiagnoses; the most common was tendinitis, which was the initial diagnosis in thirty-two (31 percent) of the patients with osteosarcoma and ten (21 percent) of those with Ewing sarcoma. The doctor's delay (the period from the first medical visit due to the symptoms to the correct diagnosis) was longer for Ewing sarcoma than for osteosarcoma (nineteen weeks and nine weeks, respectively; p < 0.0001).

CONCLUSIONS

An initial symptom of both osteosarcoma and Ewing sarcoma was pain, which was intermittent and often related to strain but not frequently felt at night. A history of trauma was common, but the clinical course often diverged from what was expected from trauma. The clinical course of osteosarcoma and particularly of Ewing sarcoma was not steadily progressive but intermittent, which often misled the doctor into believing that the condition was temporary. The most important clinical feature was a palpable mass, which was noted in more than one-third of the patients at the first visit. This finding emphasizes that a thorough physical examination is absolutely necessary.

Osseous lesions of the distal ulna: atypical location--unusual diagnosis. Report of three cases with similar imaging and different pathologic diagnoses

Three cases with destructive bone lesions of the distal end of the ulna caused by different pathologic entities (Ewing's sarcoma, osteosarcoma, rheumatoid pseudotumoral synovitis) are presented, all with similar clinical and comparable x-ray and magnetic resonance imaging features. Although the distal end of the ulna may be resected without significant functional impairment, careful evaluation of treatment strategies compatible with oncologic standards is warranted.

Endometrial endometrioid carcinomas associated with Ewing sarcoma/peripheral primitive neuroectodermal tumor

Three uterine tumors, each consisting of endometrioid carcinoma and Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) are described. The diagnosis of ES/pPNET in each case was first established in the hysterectomy specimen because each ES/pPNET was misinterpreted on the endometrial biopsy specimens as a high-grade homologous sarcoma. The ES/pPNET element in each case consisted of solid masses of small- to medium-sized round cells without Homer-Wright pseudorosettes, glial or ganglion cells, true rosettes with central lumens, or medulloepithelial tubules. Each ES/pPNET exhibited focal positive immunostaining for neuron-specific enolase, diffuse staining for vimentin, and strong cell membrane immunoreactivity for O13 (CD99), the last finding providing the first clue to the diagnosis of ES/pPNET in each case. The diagnosis in each case was confirmed by detection of EWS/FLI-1 fusion transcript through reverse transcription polymerase chain reaction. We also examined O13 immunoreactivity retrospectively in 40 cases of malignant mixed mullerian tumors (MMMT) with homologous or heterologous elements. O13 immunoreactivity was not observed in the malignant epithelium or in the homologous or heterologous sarcomas. The immunoreactivity of O13 in round cell endometrial sarcomas provides a clue to the diagnosis of ES/pPNET.