Extraskeletal mesenchymal chondrosarcoma of the mediastinum

Extraskeletal mesenchymal chondrosarcoma is a rare tumour with a predilection for the meninges and lower limb, especially the thigh region. This paper reports an extraskeletal mesenchymal chondrosarcoma occurring in the posterior mediastinum, a previously undocumented site.     

鼻腔间叶性软骨肉瘤一例

患者男,19岁,左鼻出血反复发作4个月逐渐加重.并伴有左鼻塞左眼溢泪症状出现,上般治疗无效于2008年2月入院.     

Extraskeletal mesenchymal chondrosarcoma of the pleura: report of a rare case

Mesenchymal chondrosarcoma is a rare aggressive variant of chondrosarcoma that frequently occurs in extraskeletal location. A 28-year-old female presented with a history of dyspnea and fever and succumbed to her illness before a conclusive diagnosis was established. An autopsy performed revealed the presence of an extraskeletal mesenchymal chondrosarcoma (ESMC) involving the pleura. Only one case of ESMC of the pleura has been reported previously. Herein, we report the second case of ESMC of the pleura.     

Extraskeletal myxoid chondrosarcoma with neuroendocrine differentiation

We describe a case of extraskeletal myxoid chondrosarcoma with neuroendocrine differentiation. The tumor occurred in subcutaneous tissue of the right popliteal region in a 50-year-old man. It measured 5 cm in diameter, was well circumscribed, lobular and gelatinous, and lacked any necrosis or hemorrhage. Histologically, the tumor structure was a typical of extraskeletal myxoid chondrosarcoma. The lesion was lobulated and contained small to medium-sized chondroblast-like cells with ovoid hyperchromatic nuclei and without prominent nucleoli. The cells created cords and nests and showed focally a perivascular rosette-like arrangement. A few of the tumor cells were spindle shaped. The myxoid matrix was stained with alcian blue and this reaction was resistant to prior treatment with hyaluronidase. PAS-positive glycogen was found in the cytoplasm of some tumor cells. Immunohistochemically, the tumor cells were diffusely positive for neuron specific enolase, monoclonal synaptophysin and vimentin. Following antibodies gave negative results: desmin, actins, S-100 protein, pancytokeratin, epithelial membrane antigen, chromogranin A, neurofilament protein, myelinic basic protein, glial fibrillary acidic protein. The patient is well four years after the wide excision of tumor and radiotherapy. Neuroendocrine differentiation in extraskeletal myxoid chondrosarcoma was described at first by Chhieng et al. in 1998 (1). Our observation confirms this interesting finding.     

Extraskeletal myxoid chondrosarcoma of the nasopharynx

Extraskeletal myxoid chondrosarcoma is a rare but distinct entity with special clinicopathological, immunohistochemical, cytogenetical and outcome features. This tumor developed from soft tissues. A few cases have been reported in the head and neck in the literature. We report two new cases of extraskeletal myxoid chrondrosarcoma presenting in such an unusual site: one involved the left nasal cavity of a 67-year-old man and the second the sphenoidal sinus of a 71-year-old woman. The microscopic examination revealed nests of round small cells dispersed in a myxoid stroma. The myxoid material was stained with Alcian Blue with and without hyaluronidase application whereas no PAS staining was observed. The immunohistochemical staining showed reactivity with S-100 protein and vimentin in two cases and with EMA in one case. These results allowed us to exclude other differential diagnoses: soft tissue tumors with a myxoid stroma (myxoma, myxoid liposarcoma and myxofibrosarcoma). No staining with anti-KL1 allowed us to exclude chordoma. Curative surgery was not possible. Both patients were given radiotherapy and the tumor regressed in one.     

Extraskeletal myxoid chondrosarcoma: a histochemical and immunohistochemical study

In reviewing a large series of soft tissue sarcomas, nine cases of extraskeletal myxoid chondrosarcoma have been retrieved. These tumours, which principally presented in middle-aged adults, have been examined histochemically to determine the heteroglycan content of their myxoid matrix and immunohistochemically for the presence of S-100 protein. The principal mucopolysaccharides identified were chondroitin-4 and 6-sulphate and keratan sulphate; each of the tumours was S-100 positive. The relevance of these findings to the histogenesis and differential diagnosis of these uncommon neoplasms is discussed.     

Extraskeletal myxoid chondrosarcoma arising from the retroperitoneum

A case of extraskeletal myxoid chondrosarcoma is presented. The tumor occurred in the retroperitoneum and systemic metastases were found at autopsy. The primary and metastatic tumors were soft and strikingly myxoid on gross appearance. Microscopic observation revealed undifferentiated malignant tumor having large amounts of myxoid substance and a small amount of well-differentiated chondrosarcoma element in the primary lesions. The authors obtained an immunohistochemical result that the tumor cells showed positivity for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Regarding S-100 protein, the well-differentiated chondrosarcoma element revealed intense positivity, whereas the poorly differentiated myxoid areas were not positive except for a few tumor cells. This is the first case, to our knowledge, of extraskeletal myxoid chondrosarcoma arising from the retroperitoneum, and immunohistologic findings suggest that alpha-1-antitrypsin and alpha-1-antichymotrypsin may be available markers in poorly differentiated chondrosarcomas showing a negative reaction for S-100 protein.     

Extraskeletal myxoid chondrosarcoma: Fine-needle aspiration biopsy findings

Extraskeletal myxoid chondrosarcoma (EMC) is a malignant soft tissue tumor which typically presents as an enlarging mass in an extremity. In this location it is amenable to sampling and diagnosis by fine-needle aspiration biopsy. We present our experience with three cases of EMC and discuss the differential diagnosis of myxoid soft tissue tumors. Diagn Cytopathol 1994; 11:363–366. © 1994 Wiley-Liss, Inc.     

Extraskeletal myxoid chondrosarcoma: a clinicopathological study of six cases]

The clinicopathologic, ultrastructural, and immunohistochemical features of six cases of extraskeletal myxoid chondrosarcoma are described. Light microscopic examination disclosed a lobulated neoplasm consisting of cells that tended to be round or polygonal with plenty of eosinophilic cytoplasm. The tumor cells were arranged in strands and small nests surrounded by abundant myxoid extracellular matrix. Ultrastructurally, these tumor cells displayed the signs of chondroblastic differentiation. The cytoplasm contained numerous rough endoplasmic reticulum, mitochondria and scattered glycogen granules. The intercellular matrix showed amorphous material and electronic dense and fine granules. The tumor cells in all these six cases showed diffuse immunostaining for S-100 protein but were negative for keratin. The data obtained tend to support the chondroblastic origin of this tumor.     

Extraskeletal myxoid chondrosarcoma: a study using a quick-freezing and deep-etching method

A case of extraskeletal myxoid chondrosarcoma (ESMC), which developed in the right thigh of a middle-aged Japanese woman, was studied using immunohistochemistry, conventional electron microscopy, and the quick-freezing and deep-etching (QF-DE) method. In addition to typical light microscopic findings of ESMC, conventional electron microscopy indicated that the tumor cells had features of chondrocytes. Immunohistochemically, the tumor cells showed a positive immunoreaction for S100 protein. A diagnosis of ESMC was made. An interesting observation was the ultrastructural features of collagen fibrils in the myxoid matrix highlighted by the QF-DE method. These collagen fibrils consisted of relatively thin collagen (20–35 nm) with pleated surface structures. The surface striation at 65 nm was obscure. We consider that such a finding of collagen fibrils identified by the QF-DE method is one of the characteristics of the myxoid matrix of ESMC, and this is useful for the differential diagnosis of myxoid soft tissue tumors.     

Intracerebral mesenchymal chondrosarcoma

The current case report deals with a 14-year-old girl with an intracerebral mesenchymal chondrosarcoma which has been recognized in two males and two females varying from 25 to 59 years of age. Three of the five patients had an associated malignant glioma. The present girl died eight years after her initial neurologic deficits and never received any definitive treatment for her deep seated neoplasm. These unique sarcomas may be confused with vascular lesions and have not been found to spread through the neuraxis. This unusual primary intracerebral mesenchymal chondrosarcoma appears to represent a field phenomenon with cartilaginous differentiation of glial and mesenchymal elements in the central nervous system.     

Extraskeletal myxoid chondrosarcoma. An analysis of 34 cases

Myxoid chondrosarcoma arising from extraskeletal soft tissues is a comparatively rare neoplasm characterized by ill defined nodular masses composed of cords and strands of small acidophilic cells separated by abundant mucoid stroma. Cartilaginous origin of the cells is suggested by their close resemblance to developing chondroblasts, the staining reactions of the mucoid ground substance indicating the presence of large amounts of sulfated mucopolysaccharides, and the electron microscopic findings.     

Primary meningeal mesenchymal chondrosarcoma

A primary meningeal mesenchymal chondrosarcoma initially resembled an angioblastic meningioma because the typical chondroid islands were not demonstrable. Cartilage was seen only in an intracerebral recurrence and in subsequent extracranial metastases. Ultrastructural examination of noncartilaginous regions of the tumor demonstrated mesenchymal cells with features suggestive of cartilaginous differentiation, viz, scalloped cell membranes, sac-like distension of abundant rough endoplasmic reticulum, and a matrix containing fibrillary and finely granular material. Features of meningeal or pericytic cells were not seen.     

骨外黏液样软骨肉瘤病理与鉴别诊断附4例报道并文献复习

目的 探讨骨外黏液样软骨肉瘤(extraskeletal myxoid chondrosarcoma,EMC)的临床病理特点、免疫表型及病理诊断与鉴别诊断要点.方法 收集4例EMC,对其临床、病理组织学及免疫表型进行观察并复习相关文献.结果 4例患者均为成年男性,平均年龄40.2岁,平均病程约30.3个月.主要表现为无痛性或有触痛性软组织肿块,3例发生于下肢,1例发生于胸壁.病理检查:(1)眼观见瘤体最大径平均6.5 cm,切面呈多结节状,有黏液感,界清.(2)镜检见肿瘤呈分叶状生长,瘤细胞排列呈索状、簇状或纤细网状.3例间质富于黏液样基质,1例富于软骨样基质,血管较稀疏.免疫组化:4例均表达Vim(4/4),3例表达S-100蛋白(3/4),2例表达NSE(2/4),2例表达CgA和Syn(2/4),1例表达CKpan(1/4),1例Ki-67阳性率为50%,3例Ki-67阳性率均<5%,4例均不表达SMA和EMA.结论 EMC是一种罕见的软组织肿瘤,其诊断主要依靠发生部位和组织病理学特征,免疫组化标记可帮助诊断和鉴别诊断.     

Extraskeletal myxoid chondrosarcoma: updated clinicopathological and molecular genetic characteristics

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft-tissue sarcoma characterized by distinctive morphological and cytogenetical features. As its name implies, EMC was believed to represent a variant of soft-tissue chondrosarcoma owing to its histological resemblance to chondroblastic tissue in the early stages of cartilage development or chondroid tumors such as skeletal chondrosarcoma. However, the chondroid nature has been a subject of controversy, and its line of differentiation remains to be determined. Consequently, the tumor is provisionally classified into a group of tumors of uncertain differentiation in the revised World Health Organization classification of tumors of soft tissue and bone. Moreover, immunohistochemical and ultrastructural features of neural or neuroendocrine differentiation have been recently reported in a subset of EMC, providing a new insight into their histogenetic nature. Chromosomal rearrangements involving 9q22, such as t(9;22)(q22;q12), and resultant NR4A3 fusion genes are tumor-type specific or pathognomotic for this entity and are assumed to play an important role in the development of EMC. Although the biological mechanisms and functions are largely unknown, the NR4A3-related pathway is considered a potential molecular target for future therapeutic intervention. Because of its protracted but resilient nature, a tenacious and long-term follow up is necessary for any patient.     

CD99 reactivity in mesenchymal chondrosarcoma

CD99 reactivity has been reported to be a sensitive and specific marker for Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET). However, within the group of “small round blue cell tumors,” the specificity has not been extensively examined. We investigated the immunoreactivity of mesenchymal chondrosarcoma to CD99 using the 013 antibody and found reactivity in 11 of 11 (100%) of cases, specifically in the “small round blue cell” component. All cases showed strong reactivity involving more than 50% of the small round blue cells with a distinct membrane pattern of staining. Staining was either absent or focal and weak in cartilaginous areas. We conclude that mesenchymal chondrosarcoma cannot be distinguished from ES/PNET on the basis of CD99 immunoreactivity.