Costa M J
Department of Pathology, University of California, Davis, Sacramento 95817.
Arch Pathol Lab Med. 1994 Feb;118(2):160-4.
Two cases of pleomorphic sarcoma with malignant fibrous histiocytoma phenotype that recurred following therapy with a distinctly different, more mature histologic appearance and immunohistochemical profile are reported. The first case recurred predominantly as extraosseous osteosarcoma at the same site 17 months after wide local excision. The second case recurred as widespread pulmonary, mediastinal, and hepatic metastatic disease 5 years after wide local excision and adjuvant local radiotherapy and chemotherapy with doxorubicin hydrochloride (Adriamycin) and cyclophosphamide (Cytoxan). Fine-needle aspiration of the pulmonary metastatic lesions showed predominantly spindle cells without any large, pleomorphic giant cells typical of malignant fibrous histiocytoma. The patient was treated by radiotherapy to the lung and mediastinum and by chemotherapy with ifosfamide and mesna. Biopsy of a metastatic scrotal skin nodule 9 months later showed a malignant spindle cell lesion with the histologic appearance and immunohistochemical phenotype of leiomyosarcoma. Retrospective immunohistochemical evaluation of the primary tumor showed focal desmin expression, suggesting focal leiomyosarcomatous differentiation. However, the large proportion of the primary tumor had the phenotype of malignant fibrous histiocytoma. These two cases illustrate an unusual finding of "differentiation" rather than "dedifferentiation" in a recurrent sarcoma. The transformation to osteosarcoma and differentiated leiomyosarcoma demonstrates the potential for phenotypic changes in soft-tissue sarcomas and suggests that the malignant fibrous histiocytoma phenotype and more-differentiated sarcomas such as extraosseous osteosarcoma or leiomyosarcoma are related in a common pathway in differentiation from a primitive mesenchymal stem cell.
报告了两例具有恶性纤维组织细胞瘤表型的多形性肉瘤，在治疗后复发，复发时具有明显不同、更成熟的组织学表现和免疫组化特征。第一例在广泛局部切除术后17个月，主要在同一部位复发为骨外骨肉瘤。第二例在广泛局部切除以及辅助局部放疗和使用盐酸阿霉素及环磷酰胺进行化疗5年后，复发为广泛的肺、纵隔和肝转移瘤。对肺部转移瘤进行细针穿刺活检显示，主要为梭形细胞，无任何恶性纤维组织细胞瘤典型的大的多形性巨细胞。该患者接受了肺部和纵隔放疗以及异环磷酰胺和美司钠化疗。9个月后对阴囊皮肤转移结节进行活检，显示为恶性梭形细胞病变，具有平滑肌肉瘤的组织学表现和免疫组化表型。对原发肿瘤进行回顾性免疫组化评估显示局灶性结蛋白表达，提示局灶性平滑肌肉瘤分化。然而，原发肿瘤的大部分具有恶性纤维组织细胞瘤的表型。这两例病例说明了复发性肉瘤中一种不寻常的“分化”而非“去分化”现象。向骨肉瘤和平滑肌肉瘤的转化证明了软组织肉瘤中表型变化的可能性，并提示恶性纤维组织细胞瘤表型与更分化的肉瘤如骨外骨肉瘤或平滑肌肉瘤在从原始间充质干细胞分化的共同途径中相关。
