Plečko Mihovil, Knežević Igor, Dimnjaković Damjan, Josipović Mario, Bojanić Ivan
Department of Orthopaedic Surgery, University Hospital Centre Zagreb, Šalata 6-7, 10 000 Zagreb, Croatia.
School of Medicine, University of Zagreb, Šalata 2, 10 000 Zagreb, Croatia.
Case Rep Orthop. 2020 Sep 14;2020:8851920. doi: 10.1155/2020/8851920. eCollection 2020.
Accessory soleus muscle (ASM) is a rare supernumerary anatomical variant that commonly presents as a posteromedial ankle swelling, which may become painful during physical activity. As it may mimic a soft tissue tumor, it is essential to differentiate this condition from ganglion, lipoma, hemangioma, synovioma, and sarcoma. However, ASM may also present with a painful syndrome, characterized by pain and paresthesia of the ankle and foot, mimicking the tarsal tunnel syndrome (TTS). Two cases of ASM are presented in this article. The first case had a typical presentation with painful posteromedial ankle swelling. After the initial assessment, the diagnosis was confirmed by magnetic resonance imaging (MRI), and ASM was treated by complete resection. The second case presented with pain and paresthesia in the right ankle and foot, but no swelling was noticeable. It was initially misdiagnosed by a rheumatologist and afterward overlooked on an MRI by a musculoskeletal radiology specialist and therefore mistreated by numerous physicians before being referred to our outpatient clinic. After further assessment, the diagnosis has been confirmed, and ASM was treated by complete resection combined with tarsal tunnel decompression. To the best of our knowledge, this is the first case reported in which ASM caused symptoms but presented without posteromedial swelling. This might be due to a proximally positioned belly of the ASM, followed by a tendinous insertion on the medial side of the calcaneus.
副比目鱼肌（ASM）是一种罕见的多余解剖变异，通常表现为踝关节后内侧肿胀，在体力活动时可能会疼痛。由于它可能类似于软组织肿瘤，因此将这种情况与腱鞘囊肿、脂肪瘤、血管瘤、滑膜瘤和肉瘤区分开来至关重要。然而，ASM也可能表现为一种疼痛综合征，其特征是踝关节和足部疼痛及感觉异常，类似于跗管综合征（TTS）。本文介绍了两例ASM病例。第一例有典型表现，踝关节后内侧疼痛肿胀。经过初步评估，磁共振成像（MRI）确诊后，ASM通过完全切除进行治疗。第二例表现为右踝关节和足部疼痛及感觉异常，但未发现肿胀。最初由一名风湿病学家误诊，后来一名肌肉骨骼放射科专家在MRI上也未发现，因此在转诊到我们门诊之前，多名医生都误诊误治了。经过进一步评估后确诊，ASM通过完全切除并结合跗管减压进行治疗。据我们所知，这是首例报道的ASM引起症状但无后内侧肿胀的病例。这可能是由于ASM的肌腹位置较近端，随后肌腱附着于跟骨内侧。
