Nagata Shuji, Nishimura Hiroshi, Sawano Miyuki, Shouji Yuki, Katayama Eri, Shirahama Toshihiro, Akiba Jun, Tanoue Shuichi
Department of Radiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, Fukuoka, 830-0011, Japan.
Department of Radiology, Saiseikai Futsukaichi Hospital, Chikushino, Fukuoka, Japan.
Skeletal Radiol. 2025 Jun 2. doi: 10.1007/s00256-025-04964-9.
Superficial acral fibromyxoma (SAFM) is a rare benign, slow-growing soft-tissue neoplasm with a predilection for the periungual or subungual regions of the fingers and toes. Although the histopathological and clinical features of SAFM have been extensively described, reports detailing its MRI characteristics remain limited. We present two cases of SAFM with differing MRI features and comparative histopathology. Case 1 was a 38-year-old man with a 2-year history of a painful slow-growing tumor arising on his left second finger. The tumor was hypointense on T1-weighted images (T1WI) and heterogeneously hypointense on T2-weighted images (T2WI), with faint, gradual peripheral enhancement on dynamic contrast-enhanced (DCE) MRI. The neoplasm consisted of fibroblast-type fusiform cells in a matrix of myxoid material and collagen. Case 2 was a 47-year-old man with a 10-year history of a slow-growing tumor on his right second toe. A radiograph revealed a non-calcified soft-tissue tumor with cortical erosion of the underlying distal phalanx. The tumor was hypointense on T1WI and a heterogeneous mixture of slight hyperintensity and hypointensity on T2WI, with heterogeneous enhancement on contrast-enhanced T1WI. The tumor consisted of spindle and stellate cells in an abundant myxoid matrix. Although rare, radiologists should be aware that the MRI features of SAFM are non-specific as they depend on the variable proportions of fibrous and myxoid stroma and consider them in the differential diagnosis of any slow-growing firm tumor located in the periungual or subungual regions of the fingers and toes in adult patients.
浅表性肢端纤维黏液瘤（SAFM）是一种罕见的良性、生长缓慢的软组织肿瘤，好发于手指和脚趾的甲周或甲下区域。尽管SAFM的组织病理学和临床特征已被广泛描述，但详细阐述其MRI特征的报告仍然有限。我们报告两例具有不同MRI特征和对比组织病理学的SAFM病例。病例1为一名38岁男性，左手中指出现疼痛性生长缓慢的肿瘤，病史2年。该肿瘤在T1加权像（T1WI）上呈低信号，在T2加权像（T2WI）上呈不均匀低信号，在动态对比增强（DCE）MRI上有微弱的、逐渐增强的周边强化。肿瘤由成纤维细胞型梭形细胞组成，位于黏液样物质和胶原的基质中。病例2为一名47岁男性，右足第二趾出现生长缓慢的肿瘤，病史10年。X线片显示为非钙化软组织肿瘤，伴有其下方远节指骨的皮质侵蚀。该肿瘤在T1WI上呈低信号，在T2WI上呈轻微高信号和低信号的不均匀混合，在对比增强T1WI上呈不均匀强化。肿瘤由梭形和星状细胞组成，位于丰富的黏液样基质中。尽管罕见，但放射科医生应意识到SAFM的MRI特征是非特异性的，因为它们取决于纤维和黏液样基质的不同比例，并在成年患者手指和脚趾甲周或甲下区域任何生长缓慢的实性肿瘤的鉴别诊断中考虑这些特征。
