儿童腺泡状横纹肌肉瘤的临床病理学特征及预后

Clinicopathological features and prognosis of pediatric alveolar rhabdomyosarcoma

目的探讨儿童腺泡状横纹肌肉瘤(alveolar rhabdomyosarcoma,ARMS)的临床病理学特征、诊断、鉴别诊断、治疗及预后。方法收集复旦大学附属儿科医院2008至2018年25例儿童ARMS的临床病理资料,进行形态学观察,荧光原位杂交(FISH)检测FOXO1基因,分析治疗及预后。结果儿童ARMS 25例,男13例,女12例,最小者19 d,最大者14岁,中位年龄6岁,平均年龄6.2岁。发生于四肢13例,头颈部4例,躯干3例,腹腔3例,阴囊1例,肛周1例,其中8例就诊时已发生淋巴结转移。组织学类型分别为经典型(18例)、实体型(5例)和胚胎性-腺泡状混合型(2例),典型的病理特征为成片分布深染的小圆细胞,肿瘤细胞排列成实性片状、腺泡状和乳头状,肿瘤细胞特征性表达间变性淋巴瘤激酶(ALK;21/25,84.0%)和肌源性标志物结蛋白(23/25,92.0%)、Myogenin(22/25,88.0%)、MYOD1(19/25,76.0%),部分病例肿瘤细胞表达神经内分泌标志物突触素(6/25,24.0%)和嗜铬粒素A(3/25,12.0%),绝大多数FOXO1基因重排检测阳性(24/25,96.0%)。结论儿童ARMS少见,具有独特的临床病理学特征,需要与儿童常见的其他恶性小圆细胞肿瘤鉴别,免疫组织化学标志物结蛋白、Myogenin、MYOD1、ALK及FISH FOXO1基因重排检测可以很好地辅助ARMS的诊断。

Objective To investigate the clinicopathological features, diagnosis, differential diagnosis, treatment and prognosis of pediatric alveolar rhabdomyosarcoma (ARMS). Methods The clinical and pathological data of 25 pediatric ARMS from 2008 to 2018 in Children′s Hospital of Fudan University were collected. This histomorphology was assessed, and FOXO1 gene rearrangement was detected with FISH. The treatment details and outcome were analyzed. Results There were 13 males and 12 females, with ages range from 19 days to 14 years (median 6 years, mean 6.2 years). The ARMS were located in the limbs (13 cases), head and neck (4 cases), trunk (3 cases), abdominal cavity (3 cases), scrotum (1 case) and perianal region (1 case). The ARMS were classified histologically as classic group (18 cases), solid group (5 cases) and embryonic-alveolar mixed group (2 cases). The typical pathological characteristics were small dark round cells arranged in solid, glandular and papillary patterns. The tumor cells expressed ALK (D5F3)(21/25, 84.0%), muscle origin DES (23/25, 92.0%), myogenin (22/25, 88.0%), MYOD1 (19/25, 76.0%), and in some cases they also expressed neurogenic marker Syn (6/25, 24.0%). FOXO1 gene rearrangement was detected by FISH in 24/25 cases (96.0%). Conclusion Pediatric ARMS is rare and has unique clinicopathological characteristics, and needs to be differentiated from other common small round cell malignancies in children. ALK, DES, myogenin, MYOD1 immunohistochemistry and FOXO1 gene rearrangement are valuable aid in the diagnosis of ARMS.