Clevenger Jessica A, Foster Richard S, Ulbright Thomas M
Department of Pathology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Mod Pathol. 2009 Oct;22(10):1361-6. doi: 10.1038/modpathol.2009.108. Epub 2009 Jul 24.
To gain insight concerning prognosis, we investigated seven cases of post-chemotherapy retroperitoneal lymph-node dissections from patients with testicular germ-cell tumors that contained sizable nodules of differentiated skeletal muscle, but that lacked both a primitive cellular component and mitotic activity. The patients were 18-28 years old at the time of retroperitoneal lymph-node dissection. All had a previous non-seminomatous germ-cell tumor of the testis, five of which had a teratoma component. In one the testicular tumor had foci of embryonal rhabdomyosarcoma. The retroperitoneal lymph-node dissections were performed 0.2-4.7 years after orchiectomy, all following cisplatin-based chemotherapy, and contained rhabdomyomatous tumors that ranged from 0.8-5 cm. These consisted of nodular to diffuse aggregates of fetal-type rhabdomyocytes with central to peripheral nuclei and abundant, eosinophilic, fibrillary cytoplasm with occasional cross striations. Elongated myotubes with multiple nuclei in a common sarcoplasm occurred at least focally in all cases. Mild to moderate nuclear atypia, including nuclear enlargement and nucleolar prominence, was present, but mitotic activity, necrosis, and a primitive cellular component were absent. All but one retroperitoneal lymph-node dissection also contained other teratomatous elements. Follow-up in six patients showed three were disease free at 2.2-3.4 years; two developed recurrent teratoma at 1.3-3.7 years; and a sixth developed recurrent teratoma at 0.5 and 2 years, followed at 17 years by progressive tumor with elevated alpha-fetoprotein. No patient with available follow-up developed progressive sarcoma. We conclude that rhabdomyomatous tumors in retroperitoneal lymph-node dissection specimens after chemotherapy for metastatic testicular germ-cell tumors show clinical behavior similar to teratoma rather than rhabdomyosarcoma. We believe the most likely explanation for the finding of pure rhabdomyomatous tumors in this setting, a phenomenon sometimes termed 'cytodifferentiation,' is selective persistence of differentiated tumor cells because of chemotherapy.
为深入了解预后情况，我们研究了7例睾丸生殖细胞肿瘤患者化疗后腹膜后淋巴结清扫的病例，这些病例中含有相当大的分化型骨骼肌结节，但既缺乏原始细胞成分，也没有有丝分裂活性。腹膜后淋巴结清扫时患者年龄为18 - 28岁。所有患者既往均有睾丸非精原细胞性生殖细胞肿瘤，其中5例有畸胎瘤成分。1例患者的睾丸肿瘤有胚胎性横纹肌肉瘤灶。腹膜后淋巴结清扫在睾丸切除术后0.2 - 4.7年进行，均在以顺铂为基础的化疗后，清扫出的横纹肌瘤性肿瘤大小为0.8 - 5 cm。这些肿瘤由胎儿型横纹肌细胞的结节状至弥漫性聚集组成，细胞核位于中央至周边，细胞质丰富、嗜酸性、呈纤维状，偶尔可见横纹。所有病例中至少局灶性出现了含有多个细胞核的细长肌管，位于共同的肌浆中。存在轻度至中度核异型性，包括核增大和核仁突出，但没有有丝分裂活性、坏死和原始细胞成分。除1例腹膜后淋巴结清扫外，其他清扫标本中还含有其他畸胎瘤成分。6例患者的随访结果显示，3例在2.2 - 3.4年无疾病；2例在1.3 - 3.7年出现复发性畸胎瘤；第6例在0.5年和2年出现复发性畸胎瘤，17年后出现肿瘤进展，甲胎蛋白升高。所有有随访资料的患者均未发生进展性肉瘤。我们得出结论，转移性睾丸生殖细胞肿瘤化疗后腹膜后淋巴结清扫标本中的横纹肌瘤性肿瘤，其临床行为类似于畸胎瘤而非横纹肌肉瘤。我们认为，在这种情况下发现纯横纹肌瘤性肿瘤这一有时被称为“细胞分化”的现象，最可能的解释是化疗导致分化型肿瘤细胞的选择性存活。
