Ichikawa Jiro, Kawasaki Tomonori, Onohara Kojiro, Wako Masanori, Ochiai Satoshi, Hagino Tetsuo, Haro Hirotaka
Department of Orthopedic Surgery, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Yamanashi, Japan.
Department of Pathology, Saitama Medical University International Medical Center, Hidaka 350-1298, Saitama, Japan.
Diagnostics (Basel). 2025 Jan 6;15(1):115. doi: 10.3390/diagnostics15010115.
Angiomatoid fibrous histiocytoma (AFH) is a rare intermediate tumor that is often difficult to diagnose radiologically and pathologically. Herein, we report a case of AFH in the knee that was initially misdiagnosed as a cystic lesion. The tumor was first identified eight years earlier during the patient's initial visit, when plain magnetic resonance imaging (MRI) was performed, leading to a diagnosis of a cystic lesion. At the current visit, the tumor had subsequently enlarged, and pain had appeared. Contrast-enhanced MRI was performed at our hospital, revealing enhancement suggestive of a solid tumor. A needle biopsy was performed, raising suspicion of AFH. Wide resection was performed, and AFH was diagnosed using histopathological findings and fluorescence in situ hybridization (FISH). Although there are several characteristic imaging findings of AFH, they are non-specific, and small tumors can be easily overlooked. Furthermore, histopathological findings lack specific immunohistochemical markers, making morphological appearance, combined with FISH findings recently reported as useful, important for preventing misdiagnosis. Since cystic lesions can occur in various locations besides the knee, it is recommended to perform contrast-enhanced MRI for accurate diagnosis when there is an increase in size or the appearance of symptoms, as plain MRI alone may lead to misdiagnosis.
血管外皮样纤维组织细胞瘤（AFH）是一种罕见的中间型肿瘤，在放射学和病理学上常常难以诊断。在此，我们报告一例膝关节AFH病例，该病例最初被误诊为囊性病变。该肿瘤在患者首次就诊时八年前首次被发现，当时进行了普通磁共振成像（MRI）检查，诊断为囊性病变。在本次就诊时，肿瘤随后增大并出现疼痛。我院进行了增强MRI检查，显示有强化，提示为实性肿瘤。进行了针吸活检，引发了对AFH的怀疑。进行了广泛切除，并根据组织病理学结果和荧光原位杂交（FISH）诊断为AFH。虽然AFH有一些特征性的影像学表现，但它们是非特异性的，小肿瘤很容易被忽视。此外，组织病理学结果缺乏特异性免疫组化标志物，因此形态学表现结合最近报道的有用的FISH结果对于防止误诊很重要。由于囊性病变除了膝关节外还可发生在其他各种部位，因此当病变大小增加或出现症状时，建议进行增强MRI以进行准确诊断，因为仅普通MRI可能会导致误诊。
