Department of Orthopaedic and Soft Tissue Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
Ann Diagn Pathol. 2010 Feb;14(1):8-14. doi: 10.1016/j.anndiagpath.2009.09.003. Epub 2009 Dec 8.
Mesenchymal chondrosarcoma is a rare malignant tumor in the differential diagnosis of other small, round blue cell tumors, including atypical teratoid tumor in the central nervous system (CNS) and rhabdomyosarcoma in the musculoskeletal (MSK) locations. We reviewed the morphology of CNS and MSK cases and applied a panel of immunostains. Archival cases were pulled from our files. Immunohistochemistry and follow-up were obtained. Twenty-two cases included 5 CNS (all female; mean age, 30.2) and 17 MSK (11 female and 6 male; mean age, 31.1). Both CNS and MSK examples had similar round cells, staghorn vascular pattern, increased mitotic activity, and centrally located hyaline cartilage islands. The CNS examples demonstrated more spindling and the MSK cases more necrosis. INI1 was retained in all tumors studied. Epithelial membrane antigen (EMA) and desmin were expressed focally in 35% and 50% of cases, respectively. The round cells of all cases were negative for MyoD1, myogenin, smooth muscle actin (SMA), glial fibrillary acid protein (GFAP), keratins, and estrogen receptor, as well as a panel of other antiobodies. Eighty percent of patients with follow-up had pulmonary metastases and/or died within a mean of 5 years. The CNS and MSK mesenchymal chondrosarcoma predominantly affects adult females with poor prognosis. There are only subtle morphologic differences between the CNS and MSK groups. By immunohistochemistry, mesenchymal chondrosarcoma occasionally expresses aberrant desmin and EMA but is negative for SMA, myogenin MyoD1, GFAP, and keratins, refuting true smooth or skeletal muscle, epithelial, or meningothelial phenotype. Retained INI1 separates these tumors from atypical teratoid tumor. Despite marked female predominance in our series, estrogen receptor is negative in mesenchymal chondrosarcoma.
间叶性软骨肉瘤是一种罕见的恶性肿瘤，需要与其他小圆蓝细胞肿瘤进行鉴别诊断，包括中枢神经系统（CNS）的非典型畸胎样/横纹肌样肿瘤和肌肉骨骼（MSK）部位的横纹肌肉瘤。我们回顾了 CNS 和 MSK 病例的形态学特征，并应用了一组免疫组化染色。从我们的档案中提取存档病例。获取了免疫组化和随访结果。22 例病例包括 5 例 CNS（均为女性；平均年龄 30.2 岁）和 17 例 MSK（11 例女性和 6 例男性；平均年龄 31.1 岁）。CNS 和 MSK 两个部位的肿瘤均具有相似的圆形细胞、鹿角状血管模式、增加的有丝分裂活性和中央透明软骨岛。CNS 肿瘤表现出更多的梭形，而 MSK 肿瘤则更多地发生坏死。所有研究的肿瘤均保留了 INI1。上皮膜抗原（EMA）和结蛋白在 35%和 50%的病例中分别呈局灶性表达。所有病例的圆形细胞均为 MyoD1、myogenin、平滑肌肌动蛋白（SMA）、胶质纤维酸性蛋白（GFAP）、角蛋白和雌激素受体以及一系列其他抗体阴性。80%有随访的患者在 5 年内出现肺转移和/或死亡。CNS 和 MSK 间叶性软骨肉瘤主要影响成年女性，预后不良。CNS 和 MSK 组之间仅有细微的形态学差异。免疫组化染色显示，间叶性软骨肉瘤偶尔表达异常结蛋白和 EMA，但 SMA、myogenin、MyoD1、GFAP 和角蛋白阴性，排除了真正的平滑肌或骨骼肌、上皮或脑膜上皮表型。保留的 INI1 将这些肿瘤与非典型畸胎样/横纹肌样肿瘤区分开来。尽管在我们的系列中存在明显的女性优势，但雌激素受体在间叶性软骨肉瘤中为阴性。
