Yu Lin, Wang Jian
Department of Pathology, Fudan University, Shanghai, China.
Zhonghua Bing Li Xue Za Zhi. 2013 Mar;42(3):147-52. doi: 10.3760/cma.j.issn.0529-5807.2013.03.002.
To investigate the clinicopathologic characteristics, differential diagnosis and biologic behaviors of pleomorphic rhabdomyosarcoma (PRMS).
The clinical findings, pathological features and immunophenotypes were reviewed in 44 cases of PRMS (encountered during the period from 2005 to 2012). The clinical outcome was analyzed.
There were 33 males and 11 females with age ranging from 2 to 85 years (mean, 51 years; median, 55 years). Of 44 tumors, 22 occurred in the extremities (50.0%), 16 in the trunk (36.4%), 5 in the internal organs (11.4%), and 1 in the head and neck (2.2%). Histologically, 40 tumors showed features of pleomorphic sarcoma with striking resemblance to undifferentiated pleomorphic sarcoma (UPS)/malignant fibrous histiocytoma(MFH). However, variable amount of pleomorphic rhabdomyoblasts (PRMB) were identified in most cases. The remaining 4 tumors were composed predominantly of fascicles of spindle cells with interspersed PRMBs. Immunohistiochemically, tumor cells showed diffuse staining of desmin (41/41,100%), with variable expression of myogenin (18/32, 56.3%), MyoD1 (10/21, 47.6%) and MSA (21/29, 72.4%), whereas α-SMA was negative in most cases. Follow-up data (range, 2 to 51 months) available in 29 cases showed 12 patients were alive with unresectable or recurrent disease and 17 patients were alive with no evidence of disease. The median disease-free and overall survivals was 6.0 months (mean, 9.1 months) and 8.0 months (mean, 11.2 months) respectively. Thirteen patients (44.8%) exhibited progression of disease with recurrence in 4 cases and metastasis in 9 cases. The median interval to progression was 6.0 months (mean, 5.9 months).
The presence of pleomorphic cells with strong eosinphilic cytoplasm in a pleomorphic sarcoma is suggestive of a PRMS. Diffuse, strong expression of desmin and negative staining for α-SMA further facilitate the diagnosis of PRMS and its differential diagnosis from pleomorphic leiomyosarcoma. Although PRMS may affect children or adolescents, it should be cautious not to misdiagnose anaplastic rhabdomyosarcoma as PRMS. PRMS is a high-grade sarcoma with a poor prognosis.
探讨多形性横纹肌肉瘤（PRMS）的临床病理特征、鉴别诊断及生物学行为。
回顾性分析2005年至2012年期间收治的44例PRMS患者的临床资料、病理特征及免疫表型，并分析其临床预后。
44例患者中男性33例，女性11例，年龄2～85岁（平均51岁，中位数55岁）。44例肿瘤中，22例发生于四肢（50.0%），16例发生于躯干（36.4%），5例发生于内脏器官（11.4%），1例发生于头颈部（2.2%）。组织学上，40例肿瘤表现为多形性肉瘤特征，与未分化多形性肉瘤（UPS）/恶性纤维组织细胞瘤（MFH）极为相似。然而，大多数病例中可见数量不等的多形性横纹肌母细胞（PRMB）。其余4例肿瘤主要由梭形细胞束组成，其间散在PRMB。免疫组化结果显示，肿瘤细胞弥漫性表达结蛋白（41/41，100%），肌生成素表达不一（18/32，56.3%），MyoD1表达不一（10/21，47.6%），肌动蛋白表达不一（21/29，72.4%），而大多数病例中α-SMA呈阴性。29例患者有随访资料（随访时间2～51个月），12例患者存活但有不可切除或复发性疾病，17例患者存活且无疾病证据。无病生存期和总生存期的中位数分别为6.0个月（平均9.1个月）和8.0个月（平均11.2个月）。13例患者（44.8%）出现疾病进展，其中4例复发，9例转移。疾病进展的中位间隔时间为6.0个月（平均5.9个月）。
多形性肉瘤中出现具有强嗜酸性细胞质的多形性细胞提示PRMS。结蛋白弥漫性强表达及α-SMA阴性染色有助于PRMS的诊断及其与多形性平滑肌肉瘤的鉴别诊断。虽然PRMS可发生于儿童或青少年，但应注意避免将间变性横纹肌肉瘤误诊为PRMS。PRMS是一种预后较差的高级别肉瘤。
