Meis J M, Raymond A K, Evans H L, Charles R E, Giraldo A A
Am J Surg Pathol. 1987 Jul;11(7):516-25.
Three cases of "dedifferentiated" chordoma arising in the sacrococcygeal region are presented. In all three cases, the "dedifferentiated" component arose de novo in conjunction with conventional chordoma. Two of these patients, whose tumors had a prominent malignant fibrous histiocytoma (MFH) component, died within 6 months of diagnosis. Both patients had lung metastases, one of which was histologically documented to be MFH. The third patient, whose initial tumor contained osteosarcoma, died 76 months after diagnosis and multiple recurrences. Most notable in this case was the absence of the "dedifferentiated" component (in this instance, osteosarcoma) in all of the local recurrences as well as the lung metastases. These were composed exclusively of conventional chordoma. None of the patients had a previous history of radiation therapy. The immunohistochemical staining pattern of conventional chordoma was similar to that of previous reports, where the epithelial-like cells stained for cytokeratin and epithelial membrane antigen. In addition, they stained for alpha-1-anti-chymotrypsin and vimentin. These latter two markers were also identified in the "dedifferentiated" component. As with "dedifferentiated" chondrosarcomas and liposarcomas, "dedifferentiation" in a chordoma usually portends an accelerated clinical course.
本文报告了3例发生于骶尾骨区域的“去分化”脊索瘤。在所有3例病例中，“去分化”成分均与传统脊索瘤一起新生出现。其中2例患者的肿瘤具有显著的恶性纤维组织细胞瘤（MFH）成分，在诊断后6个月内死亡。这2例患者均有肺转移，其中1例经组织学证实为MFH。第3例患者的初始肿瘤含有骨肉瘤成分，在诊断及多次复发后76个月死亡。该病例最值得注意的是，在所有局部复发灶及肺转移灶中均未出现“去分化”成分（在本例中为骨肉瘤），这些病灶均仅由传统脊索瘤构成。所有患者既往均无放疗史。传统脊索瘤的免疫组化染色模式与既往报道相似，其中上皮样细胞细胞角蛋白和上皮膜抗原染色阳性。此外，它们α1抗糜蛋白酶和波形蛋白染色也呈阳性。后两种标志物在“去分化”成分中也有表达。与“去分化”软骨肉瘤和脂肪肉瘤一样，脊索瘤中的“去分化”通常预示着临床病程加速。
