Abstract：
BACKGROUND: Giant cell tumor of soft tissue (GCT-ST) is a rare soft tissue neoplasm that is morphologically similar to but genetically distinct from giant cell tumor of bone. A novel keratin-positive GCT-ST (KPGCT-ST) harboring HMGA2::NCOR2 fusions was recently discovered. Fewer than 30 cases have been described; herein is reported an additional seven.
METHODS: Cases diagnosed as GCT-ST were retrieved from institutional archives and consultation files. The histopathologic characteristics were assessed, and the electronic medical record was reviewed.
RESULTS: Seven tumors were identified in six women and one man with a median age of 23 years. All patients underwent excision; no recurrences or metastases were noted during a median follow-up period of 7 months. Histopathologically, the tumors were characterized by a multinodular proliferation of keratin-positive mononuclear cells with evenly admixed osteoclast-like giant cells and absent neoplastic bone. A fibrous capsule with lymphoid cuffing was frequently seen. Foamy macrophages, inflammation, hemorrhage, and hemosiderin were variably present. The HMGA2::NCOR2 fusion was detected in all cases.
CONCLUSIONS: Our findings support previously reported hypotheses that KPGCT-ST is a spectrum of the same entity as the recently described xanthogranulomatous epithelial tumor. Although follow-up data are limited, to date, KPGCT-ST appears to follow an indolent course.
METHODS: Cases diagnosed as GCT-ST were retrieved from institutional archives and consultation files. The histopathologic characteristics were assessed, and the electronic medical record was reviewed.
RESULTS: Seven tumors were identified in six women and one man with a median age of 23 years. All patients underwent excision; no recurrences or metastases were noted during a median follow-up period of 7 months. Histopathologically, the tumors were characterized by a multinodular proliferation of keratin-positive mononuclear cells with evenly admixed osteoclast-like giant cells and absent neoplastic bone. A fibrous capsule with lymphoid cuffing was frequently seen. Foamy macrophages, inflammation, hemorrhage, and hemosiderin were variably present. The HMGA2::NCOR2 fusion was detected in all cases.
CONCLUSIONS: Our findings support previously reported hypotheses that KPGCT-ST is a spectrum of the same entity as the recently described xanthogranulomatous epithelial tumor. Although follow-up data are limited, to date, KPGCT-ST appears to follow an indolent course.
摘要：
背景：软组织巨细胞瘤（GCT-ST）是一种罕见的软组织肿瘤，在形态上与骨巨细胞瘤相似，但在遗传上与骨巨细胞瘤不同。最近发现了一种具有HMGA2::NCOR2融合蛋白的新型角蛋白阳性GCT-ST（KPGCT-ST）。描述了不到30例；本文报告了另外7例。
方法：从机构档案和咨询档案中检索诊断为GCT-ST的病例。评估了组织病理学特征，并审查了电子病历。
结果：在6名女性和1名男性中发现了7个肿瘤，中位年龄为23岁。所有患者均接受了切除术；在7个月的中位随访期内，未发现复发或转移。组织病理学,肿瘤的特征是角蛋白阳性单个核细胞的多结节性增殖,与均匀混合的破骨细胞样巨细胞和肿瘤骨缺失.经常看到带有淋巴袖套的纤维囊。泡沫巨噬细胞，炎症,出血,和含铁血黄素的含量不同。在所有病例中均检测到HMGA2::NCOR2融合。
结论：我们的发现支持先前报道的假设，即KPGCT-ST与最近描述的黄色肉芽肿性上皮肿瘤是同一实体的光谱。尽管随访数据有限，到目前为止,KPGCT-ST似乎遵循缓慢的过程。
方法：从机构档案和咨询档案中检索诊断为GCT-ST的病例。评估了组织病理学特征，并审查了电子病历。
结果：在6名女性和1名男性中发现了7个肿瘤，中位年龄为23岁。所有患者均接受了切除术；在7个月的中位随访期内，未发现复发或转移。组织病理学,肿瘤的特征是角蛋白阳性单个核细胞的多结节性增殖,与均匀混合的破骨细胞样巨细胞和肿瘤骨缺失.经常看到带有淋巴袖套的纤维囊。泡沫巨噬细胞，炎症,出血,和含铁血黄素的含量不同。在所有病例中均检测到HMGA2::NCOR2融合。
结论：我们的发现支持先前报道的假设，即KPGCT-ST与最近描述的黄色肉芽肿性上皮肿瘤是同一实体的光谱。尽管随访数据有限，到目前为止,KPGCT-ST似乎遵循缓慢的过程。
