Primary renal leiomyomas and leiomyosarcomas are rare, and there is a paucity of data regarding the pathologic features and outcomes of patients with these tumors. The objective of this study was to review a large series of renal smooth muscle tumors, in order to more fully elucidate their natural histories. Fifty-seven renal smooth muscle tumors were reviewed for various histopathologic features, and leiomyosarcomas were graded using the French Federation of Cancer Centers (FNCLCC) system. Tumor cores in tissue microarrays were evaluated for smooth muscle actin, desmin, h-caldesmon, calponin, myogenin, cytokeratin (OSCAR), CD117, Ki67, estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor 1 (WT1). Leiomyomas were selected on the basis of preexisting diagnostic criteria, which included a lack of cytologic atypia, necrosis, and mitotic activity (0 to 1 mitoses/10 hpf). These were found to have a strong predilection for women, tended to arise from the renal capsule, were small (mean size, 4.2 cm), and had a low Ki67 proliferative rate (mean 1.4%). In addition, they uniformly expressed all smooth muscle markers and were ER/PR/WT1 positive in nearly all cases. In 10 patients with clinical follow-up, none had a tumor recurrence. In contrast, leiomyosarcomas had an equal sex distribution, were larger (mean size, 9.8 cm), had significantly higher mitotic activity (mean 8.6 mitoses/10 hpf), with most being FNCLCC grade 2. Leiomyosarcomas expressed at least 1 muscle marker, higher Ki67 proliferative activity (mean 20.4%) than leiomyomas, and most were ER/PR/WT1 negative. Tumor recurrence occurred in 65% of patients, and 35% of patients died of disease. This study therefore validates existing criteria to distinguish between leiomyomas and leiomyosarcomas.
作者重新评估了57例具有不同形态学特征的肾脏平滑肌肿瘤，按照法国联邦癌症中心（the French Federation of Cancer Centers，FNCLCC）提出的标准对平滑肌肉瘤进行分级。通过组织芯片来评估平滑肌肌动蛋白（SMA）、结蛋白（desmin）、钙调结合蛋白（h-caldesmon）、钙调蛋白（calponin）、肌浆蛋白（myogenin）、细胞角蛋白（OSCAR）、CD117、Ki67、雌激素受体（ER）、孕激素受体（PR）和Wilms tumor 1 (WT1)蛋白的表达情况。通过先前的诊断标准（包括缺乏细胞的非典型性、坏死和核分裂像0-1个/10 hpf）来筛选平滑肌瘤，结果显示：平滑肌瘤好发于女性，倾向起源于肾被膜，肿瘤较小（平均直径4.2 cm），且Ki67增殖率较低（平均1.4%）；另外一致性表达全部平滑肌源性标记物，几乎所有病例阳性表达ER/PR/WT1；10例患者获得临床随访，均无肿瘤复发。而平滑肌肉瘤发病无性别差异，肿瘤较大（平均直径9.8 cm），且具有显著的高核分裂活性（平均8.6个核分裂像/10 hpf），大多数FNCLCC分级为2级；平滑肌肉瘤表达至少一种平滑肌标记物，Ki67增殖率（平均20.4%）比平滑肌瘤相对较高，绝大多数不表达ER/PR/WT1；65%的患者发生肿瘤复发，35%的患者死于疾病。