Department of Radiology, Salmaniya Medical Complex, Manama, Bahrain.
Department of Pathology, Salmaniya Medical Complex, Manama, Bahrain.
Skeletal Radiol. 2023 Apr;52(4):797-801. doi: 10.1007/s00256-022-04176-5. Epub 2022 Sep 7.
Most of the foot and ankle soft tissue tumors are benign. Although lipomas are the most common soft tissue tumors, intra-articular lipomas are an extremely rare entity. The majority of described cases of intra-articular lipomas occur in the knee joint. In particular, an intra-articular true lipoma of the ankle has not been reported.
We report the case of a 45-year-old woman who presented with a progressively growing ankle mass over 5 years, which started to restrict the range of motion. It was not preceded by any trauma or sports activity. On examination, a non-tender firm mass was evident on the lateral aspect of the right ankle joint with no signs of inflammation. It was non-compressible, non-mobile, and did not transilluminate. The clinical diagnosis was probable for a soft tissue ganglion. A radiograph revealed a soft tissue opacity over the anterolateral aspect of the tibiotalar joint. Magnetic resonance imaging (MRI) demonstrated a well-defined, multilobulated, encapsulated lesion located at the lateral aspect of the tibiotalar joint; with intra- and extra-articular components and an analogous signal intensity to fat. The patient underwent surgical excision of the tumor, and the histopathological examination showed mature adipose tissue representing an intra-articular lipoma. At the follow-up visit, the patient had complete resolution of symptoms and no active complaints.
An intra-articular true lipoma of the ankle is an extremely rare tumor. MRI is an invaluable diagnostic tool to make a reliable diagnosis of intra-articular masses.
大多数足踝部软组织肿瘤为良性。尽管脂肪瘤是最常见的软组织肿瘤，但关节内脂肪瘤极为罕见。已描述的大多数关节内脂肪瘤发生于膝关节。特别是，踝关节内的真正脂肪瘤尚未有报道。
我们报告了 1 例 45 岁女性病例，其 5 年来逐渐出现踝关节肿块，且逐渐限制了踝关节活动范围。发病前无任何创伤或运动活动史。体格检查发现右侧踝关节外侧有一触诊无触痛的硬结性肿块，无炎症迹象。肿块不可压缩、不活动且不透光。临床诊断为可能为软组织腱鞘囊肿。X 线片显示胫距前外侧关节有软组织不透光影。磁共振成像（MRI）显示位于胫距关节外侧的界限清楚、多分叶、有包膜的病变，具有关节内和关节外成分，信号强度与脂肪相似。患者接受了肿瘤切除术，组织病理学检查显示为关节内脂肪瘤，为成熟的脂肪组织。随访时，患者症状完全缓解，无活动性疼痛。
踝关节内真正的脂肪瘤是一种极为罕见的肿瘤。MRI 是诊断关节内肿块的一种非常有价值的诊断工具。
