Comparison of cell surface antigen HBA71 (p30/32MIC2), neuron-specific enolase, and vimentin in the immunohistochemical analysis of Ewing's sarcoma of bone.

The HBA71 antigen is an M(r) 30,000/32,000 cell surface glycoprotein (p30/32MIC2), encoded by the pseudoautosomal MIC2 gene on chromosomes X and Y, that is expressed in Ewing's sarcomas. Immunohistochemical studies demonstrate a striking specificity for HBA71 among neoplasms of diverse histologic types. In the present study, 43 cases of Ewing's sarcoma of bone were tested for HBA71 expression and six additional immunohistochemical markers regularly used in the differential diagnosis of small round-cell tumors of childhood and adolescence (neuron-specific enolase, vimentin, leukocyte common antigen, cytokeratins, muscle-specific actin, desmin). The study design included (a) random selection of Ewing's sarcoma cases from the files of Memorial Hospital beginning in 1968, (b) blind review of the original histopathologic diagnoses of ES, (c) side-by-side immunohistochemical study of recut histologic specimens, and (d) statistical analysis of immunohistochemical findings in view of clinical outcome. Of the seven antigens studied, only HBA71, neuron-specific enolase and vimentin were expressed in a significant proportion of cases. Forty-one of the 43 cases were HBA71+ (95% sensitivity); of these, 21 were neuron-specific enolase+, 29 were vimentin+, and 15 were both neuron-specific enolase+ and vimentin+. One tumor lacked all antigens, and one was vimentin+ only. Comparison of tumor tissues in five patients obtained before and after cytostatic chemotherapy showed no change in HBA71 expression or in the other antigens tested. Product-limit survival analysis (median disease-free survival was 27.3 months for the study cohort) revealed no significance of neuron-specific enolase or vimentin marker status. These results raise doubts about the usefulness of neuron-specific enolase and vimentin immunohistochemistry to distinguish Ewing's sarcoma from other small round-cell tumors of childhood and adolescence or as prognostic indicators in Ewing's sarcoma. The positive identification of Ewing's sarcoma of bone now becomes a reality using HBA71 immunohistochemistry, either as a sole method or in combination with chromosomal breakpoint analysis. This may result in achieving uniform diagnostic criteria for evaluating the biologic, therapeutic, and prognostic aspects of Ewing's sarcoma and related neoplasms.     

Extraskeletal Ewing's sarcoma. Histologic and ultrastructural observations in three cases

The histologic and ultrastructural morphology of three cases of Ewing's sarcoma of soft tissue are described and the fine structural features of extraskeletal Ewing's sarcoma are compared to those of similar round-cell tumors that are considered in the differential diagnosis. By light microscopy, these tumors are indistinguishable from Ewing's sarcoma of bone. Ultrastructurally, the salient features are also comparable to Ewing's sarcoma of bone and include: 1) absence of surface modifications; 2) cell-contact sites in the form of small thickenings of apposed membranes and large desmosome-like specializations; 3) undifferentiated cytoplasm usually containing abundant glycogen and occasionally nonspecific microfilaments; 4) significant variation in shape and irregularity of nuclear profiles. The ultrastructural features of extraskeletal Ewing's sarcoma are sufficiently distinctive to allow separation from from other small-cell malignant neoplasms in the majority of cases.     

Extraosseous Ewing's sarcoma of the kidney

Extraosseous Ewing's sarcoma/primitive neuroectodermal tumor (EES/PNET) of the kidney is an uncommon entity and usually arises from the retroperitoneum and paraspinal region. We report a case of renal EES/PNET and discuss its clinical features, histological findings and management.     

Ewing's sarcoma/primitive neuroectodermal tumor of the ureter: a case report and review of the literature

Extraosseous Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is a rare soft tissue tumor of childhood usually found in the extremities. The authors present the case of a 17-year-old girl who presented with right flank pain and hematuria and during operation was found to have a right ureteral mass. The histopathologic, immunohistochemical, ultrastructural, and cytogenetic characteristics of the excised mass were consistent with extraosseous ES/PNET. This is the first known reported case of extraosseous ES/ PNET of the ureter. The pathologic features and clinical management of this case, as well as a review of the literature, are presented.     

Solid leukemic tumor. An uncommon presentation of a common disease

Granulocytic sarcoma of the clavicle occurred in a 17-year-old boy. The patient had a densely sclerotic bony lesion with periosteal reaction and no peripheral blood manifestations of leukemia. Supraclavicular adenopathy developed after a preliminary diagnosis of Ewing's sarcoma was made, and a second biopsy was performed. Electron microscopy of the tissue showed Auer bodies and Charcot-Leyden granules characteristic of acute myelogenous leukemia. Combination chemotherapy, local irradiation, and clavicular resection have left the patient with no evidence of disease 50 months after diagnosis. Leukemia may appear as a solitary bone tumor before hematologic changes develop. Granulocytic sarcomas can have the radiographic and histologic appearance of primary bone tumors. Bone marrow examination and electron microscopy of biopsy tissue are diagnostic of leukemia and are important in all hospital investigations of round-cell tumors of bone.     

腹膜后原始神经外胚层瘤／尤因肉瘤一例报告并文献复习

目的总结腹膜后原始神经外胚层瘤／尤因肉瘤（PNET／EWS）的临床及组织病理特点,探讨其诊疗方法及预后情况。方法分析1例罕见的腹膜后PNET／EWS的临床特征、组织病理学特点以及诊断、治疗方法,同时复习近年来的国内外相关文献。结果患者当地医院行左肾切除＋左腹膜后肿物部分切除,术后病理示PNET,并在当地医院行化疗。手术后4个月肿瘤复发,再次行手术切除并行化疗,1年后检查发现肿瘤再复发。结论腹膜后PNET／EWS是一种小圆形细胞组成的恶性肿瘤。诊断时应与其他腹腔和腹膜后软组织肿瘤相鉴别。治疗以手术切除为主,化疗效果不肯定。本病有侵袭性的临床过程,远处转移早,经常局部复发和区域淋巴结转移,肺、肝、骨和骨髓转移,预后较差。     

Pathology of Ewing��s sarcoma/PNET: Current opinion and emerging concepts

Ewing’s sarcoma/PNET are small round cell tumors showing a varying degree of neuroectodermal differentiation. They are one of the commonest tumors of childhood and occur in bone and within soft tissues. Traditionally, light microscopy with the aid of immunohistochemical stains was suitable for diagnosis. But now translocation analyses are being used not only for the diagnosis and classification of small round cell tumors, but to ascertain their prognostic significance, detect micrometastasis, and monitor minimal residual disease, with potential for targeted therapy. This article analyzes the pathology, biology, and molecular aspects of Ewing’s sarcoma/PNET and discusses their clinical and therapeutic implications.     

Neuroendocrine differentiation in the glandular peripheral nerve sheath tumor. Pathologic distinction from the biphasic synovial sarcoma with glands

We studied eight glandular peripheral nerve sheath tumors and seven biphasic synovial sarcomas with glands with the objectives of (a) characterizing the nerve sheath tumors, especially with respect to a possible neuroendocrine differentiation, and (b) identifying features that could be used to distinguish between the two lesions. In a mainly immunohistochemical study, neuroendocrine differentiation of glandular cells was observed in five of eight (62.5%) nerve sheath tumors. The neuroendocrine cell markers found included chromogranin (five of eight cases), serotonin (four of seven cases), pancreatic polypeptide (two of five cases), and gastrin (two of six cases). These findings--together with histological, histochemical, and ultrastructural observations made in this and in other studies--point to a foregut type of intestinal differentiation for the glands in a majority of glandular peripheral nerve sheath tumors. Specific histological and immunohistochemical differences between the nerve sheath tumors and the synovial sarcomas were identified. The main histological differences were a sharp distinction between the spindle and glandular cells of the former but not the latter lesion, and the presence of goblet-type cells only in the glandular peripheral nerve sheath tumors. Major immunohistochemical differences included neuroendocrine differentiation and reactivity for S-100 protein and CEA (seen only or mainly in the nerve sheath tumors), and the reactivity of spindle cells of only the biphasic synovial sarcomas for epithelial membrane antigen.     

Peripheral primitive neuroectodermal tumor after radiotherapy

A 41-year-old man had a peripheral neuroectodermal tumor develop at the distal third of the fibula 4 years after radiotherapy for relapsed villonodular synovitis. This type of sarcoma usually is classified into the heterogeneic group of small round-cell bone tumors as a subdivision of Ewing's sarcomas. The immuno-staining positivity of the neoplastic cells for the neuron-specific enolase allowed the authors to make the diagnosis of a tumor with neuroectodermal origin. When the histologic study confirmed the diagnosis, the patient was treated with chemotherapy, surgical excision of the tumor, and adjuvant radiotherapy. Radiotherapy is thought to be involved in the genesis of osteogenic sarcomas as it has been shown in several reports, but there is no evidence in the literature of a peripheral neuroectodermal tumor developing after radiotherapy.     

Massive venous thrombosis of inferior vena cava as primary manifestation of renal Ewing's sarcoma

We report an extraordinarily rare case of a 17-year-old male with an extraskeletal Ewing's sarcoma (ESS) of the kidney and a massive thrombosis involving the inferior vena cava (IVC), from the iliac axis to the right atrium. This onset resembled renal cell carcinoma (RCC), although histological examination revealed it was an extraskeletal Ewing's sarcoma/peripheral neuro-ectodermal tumor (EES/PNET). EES/PNET should benefit from neoadjuvant chemotherapy to reduce the risk of metastasis and of recurrent disease due to delay in suitable treatment. Therefore, in the presence of a renal mass with tumor extension of IVC, it is reasonable to bear in mind that other tumors, apart from RCC, could occur. In such cases, a US or CT-scan guided biopsy could be useful.     

Combined modality treatment of Ewing's sarcoma of the maxilla

BACKGROUND: Primary bone sarcomas arising in osseous structures of the head and neck are rare. These tumors are often incompletely resected and treated with radiotherapy for local control. METHODS: We report a case of a 9-year-old girl with a maxillary Ewing's sarcoma. This patient was successfully treated with neoadjuvant chemotherapy followed by surgical resection and prosthetic reconstruction of the primary site. The surgical approach that was used consisted of a subtotal maxillectomy by means of a facial degloving approach, sparing the orbital contents and the inferior orbital rim and orbital floor. RESULTS: This approach produced excellent cosmetic, functional, and oncologic outcome. The patient remains without evidence of disease recurrence more than 4 years after surgery. CONCLUSIONS: This case illustrates a novel surgical approach to the resection of a maxillary Ewing's sarcoma and highlights the need for a multidisciplinary team approach to the management of head and neck sarcomas in children.     

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.     

A primitive neuroectodermal tumor on the face: case report

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma. The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin's tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face. PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation. It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.     

儿童阴茎原始神经外胚层肿瘤/尤文氏瘤1例并文献复习

目的:探讨原发于阴茎的原始神经外胚层肿瘤/尤文氏瘤(PNET/Ewing's sarcoma)的临床表现、病理特点、治疗方法。方法:分析本院收治的1例5岁患儿原发于阴茎的PNET/EWS患者的病例资料进行文献复习。结果:病理表现为小圆细胞恶性肿瘤,免疫组化结果显示CD99(+),分子生物学检查:EWS荧光原位杂交可见易位,符合原始神经外胚层肿瘤/尤文氏肉瘤诊断,该患者经过病理确诊为阴茎PNET/EWS,经45周化疗和局部放疗,瘤灶缩小。目前停药3个月。结论:原发阴茎PNET/EWS极罕见,临床症状无特异性,以阴茎增大伴疼痛为主,免疫组化及分子生物学检查有助于对PNET/EWS的确诊。     

Metastasis from scapular Ewing's sarcoma presenting as sutural diastasis: An unusual presentation

Ewing's sarcoma is a malignant non-osteogenic primary tumor of the bone. It is one of the most common primary malignant tumors of bone. Peak incidence is noticed in second decade of life with male preponderance of 1.6:1. It occurs most frequently in long bones and flat bones of pelvic girdles. In 30% cases, Ewing's sarcoma is multicentric in origin. In 14-50%, multiple metastases are present at the time of diagnosis. CNS spread is rare and isolated CNS involvement is not seen. Skull metastasis of Ewing's sarcoma is not rare compared to primary Ewing's sarcoma of the skull, but the actual frequency is unknown. We wish to report a case of "Primary Ewing's sarcoma of scapula with metastasis to Skull Vault in a Child resulting in sutural diastasis" diagnosed by clinicoradiological examination and confirmed by histopathology.     

Peripheral primitive neuroectodermal tumor -- PNET

The authors describe three cases of peripheral primitive neuroectodermal tumor. The tumor was found in soft tissues of the crus, shoulder girdle and perineum, and was also located paravertebrally and epidurally at the level of L1-L2 vertebrae. Radiological findings were not specific for this disease. The results of imaging methods (sonography, CT, MRI, DSA) were important for the assessment of tumor size, its boundary and invasion of the surrounding tissues, and for the evaluation of tumor response to therapy and detection of recurrent disease. The PNET diagnosis was based on immunohistochemical, biochemical and cytogenetic examinations. One patient died 5 months after the first clinical signs were manifested; the two patients surviving for 2 and 1 3/4 years after first sign manifestation, respectively, remained in the care of cancer specialists. Key words: skeletal Ewing's sarcoma, extra-skeletal Ewing's sarcoma, Ewing's sarcoma family of tumors, peripheral primitive neuroectodermal tumor.     

Mammary NOS-type sarcoma with CD10 expression: a rare entity with features of myoepithelial differentiation

We present an extensive immunohistochemical analysis of 7 mammary sarcomas that did not fit into any specific soft tissue sarcoma category. Histologically, they were composed of spindle cells with highly pleomorphic nuclei and abundant mitoses. Our immunohistochemical antibody panel included pan-cytokeratin (CK), basal cell type CKs (34betaE12, CK5/6, CK14, CK17) and vimentin antibodies, antibodies to established (SMA, CD10, p63, S-100, maspin, calponin, GFAP, SM-myosin), and novel (CD29, 14-3-3sigma) myoepithelial markers, as well as antibodies to CD34, desmin, h-caldesmon, steroid receptors (estrogen, progesterone, androgen), and EGFR (Her-1). Whereas CKs, CD34, desmin, and h-caldesmon were not expressed, all tumors were positive for CD10 and vimentin. CD29 and SMA were observed in 3 cases each (43%), and p63 and calponin in 2 cases each (29%). Other myoepithelial markers and steroid receptors were absent, except androgen receptors, which were expressed in one sarcoma. Five sarcomas showed positivity for EGFR. The distinction of specific, histogenetically defined sarcoma entities (such as leiomyosarcoma, angiosarcoma, liposarcoma) from NOS-type sarcoma with CD10 expression is usually clear-cut because the former exhibit a characteristic histomorphology and immunoprofile. Phyllodes tumors with stromal overgrowth or recurrent phyllodes tumors lacking epithelial structures as well as periductal stromal sarcomas can be ruled out by their frequent expression of CD34 and negativity for myoepithelial markers. The most important differential diagnosis is sarcomatoid metaplastic carcinoma because its treatment includes axillary lymphadenectomy. Since some NOS-type sarcomas with CD10 expression and most metaplastic carcinomas show positivity for CD29, SMA, and p63, differential diagnosis can be extremely difficult and requires extensive immunohistochemical evaluation for CKs and additional myoepithelial markers such as S-100, 14-3-3sigma, and maspin. The immunophenotype of NOS-type sarcomas with CD10 expression suggests that these neoplasms represent a mammary sarcoma variant with myoepithelial features.