Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA.
Am J Surg Pathol. 2010 Oct;34(10):1504-13. doi: 10.1097/PAS.0b013e3181ef70b6.
Adult-type fibrosarcoma (FS) was once considered the most common adult sarcoma, but is now considered a diagnosis of exclusion. No recent series has critically reevaluated putative FSs to estimate their true incidence. One hundred ninety-five cases diagnosed as adult FS in somatic soft tissue were retrieved from our institutional archives for the period 1960 to 2008. Thirty-two cases with insufficient material were excluded. On the basis the morphology of the final 163 cases, immunohistochemical studies (IHC) was conducted using some combination of: wide-spectrum cytokeratin (CK), EMA, high molecular weight CK, S100, Melan A, HMB-45, CD34, TLE1, CD31, HHV8, smooth muscle actin, desmin, ALK1, CD99, Myo-D1, myogenin, c-kit, INI1, CD21, p63, calretinin, WT1, and TTF1. Fluorescence in situ hybridization analysis for SYT gene rearrangement was done in 6 putative CK-negative synovial sarcomas (SS). Revised diagnoses were based on clinical, morphologic, IHC, and molecular findings. The original group of putative FS occurred in 84 males and 79 females (median 52.5 y, range 2 to 99 y), and involved various anatomic sites. Only 26 cases met WHO criteria for FS, including 2 postradiation FS. These occurred in 16 males and 10 females (median 50 y, range 6 to 74 y), and involved the lower extremities (12 cases), head/ neck (5 cases), trunk (4 cases), upper extremities (3 case), and mediastinum/abdomen (2 cases). Clinical follow-up information was available for 24 of 26 (92%) cases, with a median of 5 years follow-up (range <1 to 35 y). Twelve patients (50%) died of locally aggressive and/or metastatic disease (median follow-up 1-year; range <1 to 8 y), 6 patients (25%) were alive without disease (median follow-up 11.5 y; range 2.5 to 35 y), and 6 patients (25%) died of other causes (median follow-up 10 y; range 9 to 18 y) (). Fluorescence in situ hybridization analysis was positive for SYT gene rearrangement in all cases tested. Non-FS (137 cases) were reclassified as: undifferentiated pleomorphic sarcoma (32 cases), SS (21 cases), solitary fibrous tumor (14 cases), myxofibrosarcoma (11 cases), malignant peripheral nerve sheath tumor (8 cases), FS dermatofibrosarcoma protuberans, and desmoplastic melanoma (4 cases each), low-grade fibromyxoid sarcoma, sarcomatoid carcinoma, desmoid-type fibromatosis, rhabdomyosarcoma, myofibroblastic sarcoma, spindle-cell liposarcoma (3 cases each), sclerosing epithelioid FS, fibroma-like epithelioid sarcoma, leiomyosarcoma, cellular fibrous histiocytoma (2 cases each), and others (17 cases). Using modern diagnostic criteria with ancillary IHC and molecular genetics, we have been able to reclassify 84% of putative FS. Exclusive of undifferentiated pleomorphic sarcoma, the distinction of which from FS is subjective, 64% of putative FS were reclassified, most commonly as monophasic SS and solitary fibrous tumor. We conclude that true FS is exceedingly rare, accounting for <1% of approximately 10,000 adult soft tissue sarcomas seen at our institution during this time period, and should be diagnosed with great caution.
成人型纤维肉瘤（FS）曾被认为是最常见的成人肉瘤，但现在被认为是一种排除性诊断。最近没有任何系列研究重新评估所谓的 FS，以估计其真实发病率。从我们机构的档案中检索到 195 例在体软组织中诊断为成人 FS 的病例，在 1960 年至 2008 年期间。由于材料不足，排除了 32 例。基于最终 163 例病例的形态学，使用广泛的细胞角蛋白（CK）、EMA、高分子量 CK、S100、Melan A、HMB-45、CD34、TLE1、CD31、HHV8、平滑肌肌动蛋白、结蛋白、ALK1、CD99、Myo-D1、myogenin、c-kit、INI1、CD21、p63、钙视网膜蛋白、WT1 和 TTF1 的一些组合进行了免疫组织化学研究（IHC）。对 6 例可能为 CK 阴性的滑膜肉瘤（SS）进行了 SYT 基因重排的荧光原位杂交分析。根据临床、形态学、IHC 和分子发现进行了修订诊断。原始的 FS 组发生在 84 名男性和 79 名女性中（中位数为 52.5 岁，范围为 2 至 99 岁），涉及各种解剖部位。只有 26 例符合 FS 的 WHO 标准，包括 2 例放疗后 FS。这些发生在 16 名男性和 10 名女性中（中位数为 50 岁，范围为 6 至 74 岁），涉及下肢（12 例）、头/颈（5 例）、躯干（4 例）、上肢（3 例）和纵隔/腹部（2 例）。可获得 26 例中的 24 例（92%）的临床随访信息，中位随访时间为 5 年（范围<1 至 35 岁）。12 例患者（50%）死于局部侵袭性和/或转移性疾病（中位随访时间为 1 年；范围<1 至 8 岁），6 例患者（25%）无疾病存活（中位随访时间为 11.5 年；范围 2.5 至 35 岁），6 例患者（25%）死于其他原因（中位随访时间为 10 年；范围 9 至 18 岁）。对所有测试病例均进行了 SYT 基因重排的荧光原位杂交分析呈阳性。非 FS（137 例）被重新分类为：未分化多形性肉瘤（32 例）、SS（21 例）、孤立性纤维瘤（14 例）、黏液纤维肉瘤（11 例）、恶性外周神经鞘瘤（8 例）、FS 隆突性皮肤纤维肉瘤和促结缔组织增生性黑色素瘤（各 4 例）、低度纤维黏液样肉瘤、肉瘤样癌、促结缔组织增生性纤维瘤、横纹肌肉瘤、肌纤维母细胞瘤、梭形细胞脂肪肉瘤（各 3 例）、硬化性上皮样 FS、纤维瘤样上皮样肉瘤、平滑肌瘤、细胞性纤维组织细胞瘤（各 2 例）和其他（17 例）。使用现代诊断标准、辅助 IHC 和分子遗传学，我们能够重新分类 84%的 FS。不包括未分化多形性肉瘤，因为主观上难以与 FS 区分，因此重新分类了 64%的 FS，最常见的是单相 SS 和孤立性纤维瘤。我们的结论是，真正的 FS 非常罕见，占我们机构在此期间看到的大约 10000 例成人软组织肉瘤的<1%，应谨慎诊断。
