Miettinen Markku, Finnell Val, Fetsch John F
Department of Soft Tissue Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
Am J Surg Pathol. 2008 Jul;32(7):996-1005. doi: 10.1097/PAS.0b013e318160736a.
Ossifying fibromyxoid tumor (OFT) is a unique soft tissue tumor of uncertain histogenesis. The majority of reported cases (approximately 220) have pursued a benign clinical course. However, recent literature has emphasized the existence of morphologically atypical and clinically malignant examples of this tumor and proposed guidelines for assessment of biologic potential. In the present study, we evaluated 104 cases of OFT from the Armed Forces Institute of Pathology, accessioned between the years 1970 and 2007. Herein, OFT was strictly defined as a tumor with lobular architecture, predominantly epithelioid cell morphology, a low level of atypia, corded and trabecular growth patterns, moderate amounts of myxocollagenous matrix, and often, focal peripheral metaplastic bone formation. Tumors that lacked conventional morphology were excluded. The exclusion group included cutaneous mixed tumors, low-grade fibromyxoid sarcomas, and extraskeletal osteosarcomas. The OFTs occurred in 64 men and 40 women with a median age of 50 years (range, 21 to 81 y). The tumor size ranged from 0.7 to 17 cm (median, 3 cm). The mitotic rate varied from 0 to 41 mitotic figures per 50 HPFs (median, 2/50 HPFs). Tumor cell nuclei typically contained small, distinct nucleoli, and necrosis was infrequent (11/104). The great majority of tumors (67/71, 94%) were positive for S100 protein, whereas only occasional examples had (focal) positivity for desmin, glial fibrillary acidic protein, and an AE1/AE3 keratin cocktail. Local recurrences were documented in 9 of 41(22%) living patients, usually 10 or more years after primary surgery, but there were no metastases. A mitotic rate of >2 mitotic figures/50 HPFs was a risk factor for local recurrence, but necrosis, tumor size, the presence of satellite nodules, and positive margins were not. When OFT is strictly defined by the criteria noted above, there is potential for local recurrence, but there seems to be little or no risk for metastasis.
骨化性纤维黏液样肿瘤（OFT）是一种组织发生不明的独特软组织肿瘤。大多数已报道的病例（约220例）临床过程呈良性。然而，最近的文献强调了该肿瘤存在形态学不典型和临床恶性的病例，并提出了评估生物学潜能的指导原则。在本研究中，我们评估了武装部队病理研究所1970年至2007年间收录的104例OFT。在此，OFT被严格定义为具有小叶结构、主要为上皮样细胞形态、低异型性水平、条索状和小梁状生长模式、中等量黏液胶原基质且常伴有局灶性周边化生骨形成的肿瘤。缺乏传统形态的肿瘤被排除。排除组包括皮肤混合瘤、低级别纤维黏液样肉瘤和骨外骨肉瘤。OFT发生于64名男性和40名女性，中位年龄为50岁（范围21至81岁）。肿瘤大小范围为0.7至17厘米（中位值3厘米）。有丝分裂率为每50个高倍视野0至41个有丝分裂象（中位值2/50个高倍视野）。肿瘤细胞核通常含有小而清晰的核仁，坏死少见（11/104）。绝大多数肿瘤（67/71，94%）S100蛋白呈阳性，而仅偶尔有病例（局灶性）结蛋白、胶质纤维酸性蛋白和AE1/AE3角蛋白混合物呈阳性。41名在世患者中有9例（22%）记录有局部复发，通常在初次手术后10年或更长时间，但无转移。有丝分裂率>2个有丝分裂象/50个高倍视野是局部复发风险因素，但坏死、肿瘤大小、卫星结节的存在和切缘阳性并非风险因素。当按照上述标准严格定义OFT时，存在局部复发可能，但似乎几乎没有转移风险。
