Leuschner I, Newton W A, Schmidt D, Sachs N, Asmar L, Hamoudi A, Harms D, Maurer H M
Children's Cancer Study Group, Children's Hospital, Columbus, Ohio 43205.
Am J Surg Pathol. 1993 Mar;17(3):221-30. doi: 10.1097/00000478-199303000-00002.
We reviewed 173 cases of paratesticular rhabdomyosarcoma (RMS) of Intergroup Rhabdomyosarcoma Studies (IRS)-I, -II, and -III for evaluation of possible histological factors that might account for the good prognosis of these patients. Almost all cases (161 of 173 cases, 93.1%) occurring in this site were of embryonal histology. A spindle-cell subtype of embryonal RMS was identified that presented a storiform growth pattern with abundant collagen between the tumor cells in most cases. Other tumors of this subtype showed an arrangement of tumor cells in bundles with a low to moderate amount of collagen, resembling a leiomyosarcoma. The other embryonal RMS in this site had the classical embryonal cytology. The spindle-cell subtype was highly differentiated by immunohistochemistry and electron microscopy. Lymph node metastasis was found in seven of 43 patients (16.3%) with a RMS of spindle-cell subtype, compared with 40 of 112 patients (35.7%) with RMS of non-spindle-cell type. Clinical data from patients with spindle-cell subtypes of the paratesticular lesions revealed that they almost always had an association with clinical groups of limited disease (32 patients, 74.4%, with Group I; 10 patients, 23.3%, with Group II disease) and a significantly better prognosis (95.5% survival at 5 years) when compared with patients with the classic embryonal variant of RMS (80% survival at 5 years, p < 0.035). The incidence and anatomic distribution of this spindle cell subtype of embryonal RMS was estimated on 800 randomly selected patients from IRS-II. It was found in the head and neck, extremities, orbit, and some other sites, but 30.6% were located in the paratesticular area. Patients with spindle cell RMS of nonparatesticular sites usually had more extensive disease compared with patients having paratesticular lesions; two thirds of the cases had gross residual tumor after surgery or metastatic tumor at diagnosis. We conclude that spindle-cell RMS is a subtype of embryonal RMS with a very favorable prognosis. The site factor of the paratesticular localization may allow earlier diagnosis of the spindle-cell lesions compared with other sites. Other unknown factors may also play a role.
我们回顾了国际横纹肌肉瘤协作组（IRS）-I、-II和-III研究中的173例睾丸旁横纹肌肉瘤（RMS）病例，以评估可能解释这些患者良好预后的组织学因素。几乎所有发生在该部位的病例（173例中的161例，93.1%）均为胚胎型组织学。我们识别出一种胚胎型RMS的梭形细胞亚型，在大多数情况下，其呈现出束状生长模式，肿瘤细胞之间有丰富的胶原纤维。该亚型的其他肿瘤显示肿瘤细胞呈束状排列，胶原纤维含量低至中等，类似平滑肌肉瘤。该部位的其他胚胎型RMS具有典型的胚胎型细胞学特征。通过免疫组织化学和电子显微镜检查发现，梭形细胞亚型高度分化。在43例梭形细胞亚型RMS患者中，有7例（16.3%）发生淋巴结转移，相比之下，112例非梭形细胞型RMS患者中有40例（35.7%）发生淋巴结转移。睾丸旁病变的梭形细胞亚型患者的临床资料显示，与经典胚胎型RMS患者相比，他们几乎总是与局限性疾病临床组相关（32例，74.4%，属于I组；10例，23.3%，属于II组疾病），且预后明显更好（5年生存率为95.5%）（经典胚胎型RMS患者5年生存率为80%，p<0.035）。我们根据IRS-II中随机选取的800例患者估计了胚胎型RMS这种梭形细胞亚型的发病率和解剖分布。在头颈部、四肢、眼眶和其他一些部位发现了该亚型，但30.6%位于睾丸旁区域。与睾丸旁病变患者相比，非睾丸旁部位的梭形细胞RMS患者的疾病通常更广泛；三分之二的病例在诊断时术后有肉眼可见的残留肿瘤或有转移瘤。我们得出结论，梭形细胞RMS是胚胎型RMS的一种亚型，预后非常良好。与其他部位相比，睾丸旁定位的部位因素可能使梭形细胞病变更早得到诊断。其他未知因素可能也起作用。
