PDF(Pubmed)
Abstract：
Somatic-type malignancy (STM) can occur infrequently within a primary or metastatic testicular germ cell tumor (TGCT) and is associated with dismal prognosis and survival. STM with chondrosarcomatous features is exceedingly rare and head and neck involvement has not been previously documented. A 39-year-old white man presented with nasal obstruction and epistaxis. Imaging disclosed a 6.9-cm expansile tumor involving the nasal cavity and skull base with intraorbital and intracranial extension. The histopathologic properties of the tumor were compatible with chondrosarcoma, grade II-III. Immunohistochemically, malignant cells were strongly and diffusely positive for S100 and epithelial markers, and showed loss of SMARCB1 expression. IDH1/2 mutations were not detected. Following whole-body PET scan, a 7.0-cm left testicular mass was discovered and diagnosed as seminoma with syncytiotrophoblastic cells, stage pT3NXM1b. Extensive retroperitoneal, mediastinal, and supraclavicular lymphadenopathy was also noticed. Histopathologic examination of the left supraclavicular lymph node revealed metastatic seminoma. By FISH, most metastatic nodal seminoma cells harbored 1 to 4 copies of isochromosome 12p, while the chondrosarcoma featured duplication of 12p. Presence of a malignant TGCT with disseminated supradiaphragmatic lymphadenopathy, the unique immunophenotypic properties of the skull-based chondrosarcoma and lack of IDH1/2 aberrations with gain of 12p strongly support the diagnosis of STM chondrosarcoma arising from metastatic TGCT. The patient did not respond to chemotherapy and succumbed three months after diagnosis. Although exceedingly uncommon, metastasis to the head and neck may occur in patients with TGCT. This case of STM chondrosarcoma demonstrated divergent immunophenotypic and molecular characteristics compared to \"typical\" examples of head and neck chondrosarcoma. High index of suspicion is advised regarding the diagnosis of lesions that present with otherwise typical histomorphology but unexpected immunohistochemical or molecular features.
摘要：
在原发性或转移性睾丸生殖细胞肿瘤（TGCT）中，体细胞型恶性肿瘤（STM）很少发生，并且与预后和生存不良有关。具有软骨肉瘤特征的STM极为罕见，并且以前没有记录过头颈部受累。一名39岁的白人男子出现鼻塞和鼻出血。影像学显示有6.9厘米的扩张性肿瘤，累及鼻腔和颅底，并伴有眶内和颅内延伸。肿瘤的组织病理学特性与软骨肉瘤一致，II-III级。免疫组织化学，恶性细胞对S100和上皮标志物呈强烈和弥漫性阳性，并显示SMARCB1表达缺失。未检测到IDH1/2突变。全身PET扫描后,发现了一个7.0厘米的左睾丸肿块，并诊断为带有合胞体滋养层细胞的精原细胞瘤，阶段pT3NXM1b。广泛的腹膜后，纵隔,并注意到锁骨上淋巴结肿大。左锁骨上淋巴结的组织病理学检查显示转移性精原细胞瘤。由FISH,大多数转移性淋巴结精原细胞瘤细胞含有1至4个拷贝的12p同工染色体，而软骨肉瘤表现为12p的重复。存在恶性TGCT伴播散性膈上淋巴结病，颅骨软骨肉瘤的独特免疫表型特性和缺乏IDH1/2像差,增益为12p,强烈支持了转移性TGCT引起的STM软骨肉瘤的诊断.患者对化疗无反应，诊断后三个月死亡。虽然非常罕见，TGCT患者可能发生头颈部转移。与头颈部软骨肉瘤的“典型”实例相比，该STM软骨肉瘤病例表现出不同的免疫表型和分子特征。对于具有其他典型组织形态学但意外的免疫组织化学或分子特征的病变，建议高度怀疑。
