den Bakker M A, Hegt V Noordhoek, Sleddens H B F M, Nuijten A S M, Dinjens W N M
Stichting Laboratorium Pathologie en Cytologie (PATHAN), St Franciscus Gasthuis, Erasmus Medical Care Rotterdam, Rotterdam, The Netherlands.
Histopathology. 2002 Jan;40(1):65-70. doi: 10.1046/j.1365-2559.2002.01290.x.
To document and find evidence for the rare occurrence of malignant progression of a benign uterine leiomyoma with divergent mesenchymal differentiation. In a 54-year-old female a large pedunculated tumour was encountered which had suddenly increased in size and had apparently arisen at the site of a subserosal uterine leiomyoma first described 19 years earlier. The tumour seemed histologically diverse in its composition. The possibility of malignant progression of the benign leiomyoma with divergent mesenchymal differentiation was entertained.
In the resected tumour, smooth muscle, osseous and adipose components were identified and these were assessed using recognized histological criteria of malignancy. In addition to a benign smooth muscle component, malignant leiomyosarcomatous tissue was seen in addition to a malignant osseous component and a malignant adipose component. The tumour thus met the criteria of a malignant mesenchymoma. The relationship of the different components of the tumour was analysed by immunohistochemistry and with molecular loss of heterozygosity (LOH) analysis. In the osseous and leiomyosarcomatous components a similar LOH pattern was observed. The adipose component showed a distinct LOH pattern. Retention of smooth muscle differentiation in the osseous component was demonstrated by desmin immunostaining.
Malignant transformation of benign uterine leiomyoma may rarely occur. Mesenchymal stem cells underlying these tumours may show divergent mesenchymal differentiation.
记录并寻找具有不同间充质分化的良性子宫平滑肌瘤罕见发生恶性进展的证据。在一名54岁女性中，发现了一个大的带蒂肿瘤，其大小突然增加，显然起源于19年前首次描述的浆膜下子宫平滑肌瘤部位。该肿瘤在组织学上似乎成分多样。考虑到具有不同间充质分化的良性平滑肌瘤发生恶性进展的可能性。
在切除的肿瘤中，识别出平滑肌、骨和脂肪成分，并使用公认的恶性组织学标准对其进行评估。除了良性平滑肌成分外，还发现了恶性平滑肌肉瘤组织，以及恶性骨成分和恶性脂肪成分。因此，该肿瘤符合恶性间叶瘤的标准。通过免疫组织化学和分子杂合性缺失（LOH）分析来分析肿瘤不同成分之间的关系。在骨和平滑肌肉瘤成分中观察到相似的LOH模式。脂肪成分显示出独特的LOH模式。骨成分中结蛋白免疫染色证实保留了平滑肌分化。
良性子宫平滑肌瘤可能很少发生恶性转化。这些肿瘤潜在的间充质干细胞可能表现出不同的间充质分化。
