Yu Lin, Lao I Weng, Wang Jian
1Department of Pathology, Fudan University Shanghai Cancer Center, Fudan University 2Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Pathology. 2015 Dec;47(7):667-72. doi: 10.1097/PAT.0000000000000321.
We present our experience with seven cases of epithelioid rhabdomyosarcoma (RMS) to further characterise its clinicopathological features. There were five males and two females with ages ranging from 19 to 84 years (mean 56 years). Four tumours occurred in the somatic soft tissue, two in organs and one in the bone. The mean tumour size was 10.7 cm (range 3.5-15 cm). Histologically, six tumours were characterised by sheet-like growth of uniform epithelioid cells with large vesicular nuclei, prominent nucleoli, high mitotic activity and moderate to abundant amphophilic-to-eosinophilic cytoplasm. One tumour was composed of dyscohesive cells with rhabdoid appearance embedded in a myxoid matrix. Features suggestive of rhabdomyoblastic differentiation were absent. However, immunohistochemical study revealed skeletal muscle differentiation in all cases. Of note, focal expression of epithelial markers with co-expression of neuroendocrine markers was noted in five and three cases, respectively. Of six patients with follow-up, one experienced local recurrence and three developed metastases. To date, three patients have died of disease within 14 months. This study further demonstrates that epithelioid RMS represents a distinct variant of RMS with an aggressive behaviour. It may be misdiagnosed as poorly differentiated neuroendocrine carcinoma due to co-expression of epithelial and neuroendocrine markers.
我们介绍了7例上皮样横纹肌肉瘤（RMS）的经验，以进一步明确其临床病理特征。患者中男性5例，女性2例，年龄范围为19至84岁（平均56岁）。4例肿瘤发生于躯体软组织，2例发生于器官，1例发生于骨骼。肿瘤平均大小为10.7 cm（范围3.5 - 15 cm）。组织学上，6例肿瘤的特征为一致的上皮样细胞呈片状生长，细胞核大呈空泡状，核仁突出，有丝分裂活性高，胞质中等至丰富，呈嗜双色性至嗜酸性。1例肿瘤由散在的具有横纹肌样外观的细胞组成，包埋于黏液样基质中。未见提示横纹肌母细胞分化的特征。然而，免疫组化研究显示所有病例均有骨骼肌分化。值得注意的是，分别有5例和3例出现上皮标志物局灶性表达并伴有神经内分泌标志物共表达。在6例有随访的患者中，1例出现局部复发，3例发生转移。迄今为止，3例患者在14个月内死于该疾病。本研究进一步表明，上皮样RMS是RMS的一种独特变体，具有侵袭性。由于上皮和神经内分泌标志物的共表达，它可能被误诊为低分化神经内分泌癌。
