Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimore, MD 21231, USA.
Am J Surg Pathol. 2013 Mar;37(3):344-55. doi: 10.1097/PAS.0b013e31826e0271.
In its classical form, embryonal rhabdomyosarcoma (ERMS, botryoid type) is a vaginal neoplasm occurring in infants and young girls and is often not considered in the differential diagnosis of uterine corpus and cervical spindle cell tumors in adult women. Clinicopathologic and immunohistochemical features of 25 cases of ERMS in women 20 years of age or older were analyzed. Patient age ranged from 20 to 89 years (mean, 44.4 y; median, 46 y), with 8 patients aged 20 to 39 years, 14 patients aged 40 to 59 years, and 3 patients older than 60 years of age. Tumors originated in the cervix in 20 cases and in the uterine corpus in 5. They were characterized by an edematous hypocellular spindle cell proliferation, typically with cellular condensation beneath epithelial surfaces (cambium layer), in which tightly packed hypercellular foci were scattered. Neoplastic cells had hyperchromatic nuclei and minimal cytoplasm, usually with delicate cytoplasmic processes. Occasionally, elongated or globular cells with eosinophilic cytoplasm (rhabdomyoblasts) were evident, but cytoplasmic cross-striations were only rarely identified. Apoptotic bodies and mitotic figures were usually identified in the hypercellular foci. Hemorrhage was common, often making recognition of the hypercellular foci difficult. Desmin and myogenin were coexpressed in 22 of 23 (95.6%) tumors evaluated. Proliferative activity, as assessed by Ki-67 expression, was notably elevated in all tumors evaluated, typically concentrated in the hypercellular foci. Estrogen and progesterone receptors were expressed focally in only 3 of 12 (25%) and 1 of 8 (12.5%) tumors evaluated, respectively. Follow-up was available in 7 cases. Five patients were alive without evidence of disease with follow-up of 3 to 8 years, and 1 patient was alive with disease at 5 months. One patient died at 5 months with pulmonary nodules, but it was not determined whether this was due to metastatic ERMS or the patient's known ductal breast carcinoma. ERMS has a broader clinical profile than classically expected and should be considered in the differential diagnosis of a uterine corpus or cervical spindle cell tumor, regardless of patient age. Recognition can be rendered difficult by the hypocellular background, which can suggest a benign polyp or low-grade tumor, and hemorrhage, which can obscure the characteristic hypercellular foci. Identification of hypercellular foci in which mitotic activity and apoptotic bodies are found, desmin and myogenin are coexpressed, proliferative activity is notably elevated, and hormone receptor expression is usually absent is very useful for establishing the diagnosis.
在其经典形式中，胚胎性横纹肌肉瘤（ERMS，葡萄状型）是一种发生于婴儿和年轻女孩的阴道肿瘤，通常不在成年女性子宫体和宫颈梭形细胞肿瘤的鉴别诊断中考虑。分析了 25 例 20 岁及以上女性 ERMS 的临床病理和免疫组织化学特征。患者年龄 20 至 89 岁（平均 44.4 岁；中位数 46 岁），20 岁至 39 岁 8 例，40 岁至 59 岁 14 例，60 岁以上 3 例。肿瘤起源于宫颈 20 例，子宫体 5 例。其特征为水肿性、细胞稀少的梭形细胞增生，通常在上皮表面（芽基层）下有细胞浓缩，其中散布着紧密排列的高细胞灶。肿瘤细胞有深染的核和很少的细胞质，通常有纤细的细胞质突起。偶尔，可见到有嗜酸性细胞质的长形或球形细胞（横纹肌母细胞），但很少见到细胞质横纹。凋亡小体和有丝分裂象通常在高细胞灶中被识别到。出血很常见，常使高细胞灶难以识别。desmin 和 myogenin 在 23 例中有 22 例（95.6%）被评估的肿瘤中共同表达。Ki-67 表达评估的增殖活性在所有被评估的肿瘤中均显著升高，通常集中在高细胞灶中。雌激素受体和孕激素受体在被评估的 12 例中的 3 例（25%）和 8 例中的 1 例（12.5%）中仅局灶表达。7 例可获得随访。5 例患者无疾病存活，随访 3 至 8 年，1 例患者存活，疾病持续 5 个月。1 例患者在 5 个月时死于肺结节，但无法确定这是由于转移性 ERMS 还是患者已知的乳腺导管癌所致。ERMS 的临床特征比经典预期的更为广泛，无论患者年龄如何，都应在子宫体或宫颈梭形细胞肿瘤的鉴别诊断中考虑。低细胞背景可能提示良性息肉或低度肿瘤，且出血可能使特征性的高细胞灶难以识别，这会使识别变得困难。发现高细胞灶、有丝分裂活性和凋亡小体、desmin 和 myogenin 共同表达、增殖活性显著升高以及激素受体表达通常缺失，对建立诊断非常有用。
