Tajima Shogo, Waki Michihiko, Fukuyama Masashi
Department of Pathology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
Med Mol Morphol. 2016 Dec;49(4):238-242. doi: 10.1007/s00795-015-0103-6. Epub 2015 Apr 25.
Although primary leiomyosarcoma of the kidney is extremely rare, it is the most common sarcoma of the kidney. Leiomyosarcoma with a large pleomorphic component is designated as pleomorphic leiomyosarcoma. The pleomorphic component is usually similar to undifferentiated high-grade pleomorphic sarcoma, although it variably expresses smooth muscle markers on immunohistochemistry. In the few reported cases of pleomorphic leiomyosarcoma of the kidney, cases with the pleomorphic component showing distinct nodularity similar to dedifferentiated leiomyosarcoma have not been described, to the best of our knowledge. Herein, we present a case of a 49-year-old woman with pleomorphic leiomyosarcoma in the kidney showing distinct nodularity of smooth muscle marker-expressing pleomorphic cells within a background of classic leiomyosarcoma. Along with the classification as a pleomorphic leiomyosarcoma, suggesting aggressive clinical behavior, the renal origin itself might also be a predictor of poor prognosis, as shown in a previous study. This case also involved concomitant distant metastases, already present during the initial detection of the renal tumor.
尽管原发性肾平滑肌肉瘤极为罕见，但它却是肾脏最常见的肉瘤。具有大量多形性成分的平滑肌肉瘤被称为多形性平滑肌肉瘤。多形性成分通常类似于未分化的高级别多形性肉瘤，不过在免疫组织化学上它可不同程度地表达平滑肌标志物。据我们所知，在少数已报道的肾多形性平滑肌肉瘤病例中，尚未描述过其多形性成分呈现出与去分化平滑肌肉瘤相似的明显结节状的情况。在此，我们报告一例49岁女性的肾多形性平滑肌肉瘤病例，在经典平滑肌肉瘤背景下，表达平滑肌标志物的多形性细胞呈现出明显的结节状。除了归类为多形性平滑肌肉瘤提示侵袭性临床行为外，正如先前一项研究所显示的，肾脏起源本身也可能是预后不良的一个预测因素。该病例还伴有远处转移，在最初检测到肾肿瘤时就已存在。
