Lim Chiao Yee, Duski Suryasmi, Chye Ping Ching
Department of Orthopaedic Surgery, Kuala Lumpur Hospital, 50586 Kuala Lumpur, Malaysia.
Case Rep Orthop. 2019 Aug 14;2019:5156032. doi: 10.1155/2019/5156032. eCollection 2019.
Intramuscular myxomas are rare, benign mesenchymal tumors. Tumor location in the forearm is very rare among all the intramuscular myxomas. To the best of our knowledge, there were two cases of supinator intramuscular myxoma reported in the literature, and we intend to report the third case of supinator myxoma with encasement of the posterior interosseous nerve (PIN). A 67-year-old lady presented with history of left proximal forearm swelling for the past 5 years. Magnetic resonance imaging showed a lobulated multiseptated lesion seen within left supinator muscle, which was hyperintense on T2-weighted images (T2WI) and hypointense on T1-weighted images (T1WI), with peripheral enhancement post contrast. The tissue diagnosis of myxoma was confirmed via an open biopsy. She underwent en bloc resection of the tumor. The PIN was encased by the tumor; it was preserved and carefully released from the tumor. The nerve sheath served as an excision margin. In conclusion, we present a rare case of an intramuscular myxoma in the supinator muscle. In view of the location, extra attention should be paid during excision surgery to locate the PIN and to avoid damaging the surrounding structures.
肌内黏液瘤是一种罕见的良性间叶组织肿瘤。在前臂的肿瘤位置在所有肌内黏液瘤中非常罕见。据我们所知，文献中报道了两例旋后肌肌内黏液瘤，我们打算报告第三例伴有骨间后神经（PIN）包绕的旋后肌黏液瘤。一名67岁女性，有左侧前臂近端肿胀5年的病史。磁共振成像显示在左侧旋后肌内可见一个分叶状多分隔病变，在T2加权像（T2WI）上呈高信号，在T1加权像（T1WI）上呈低信号，增强后周边强化。通过开放活检确诊为黏液瘤组织学诊断。她接受了肿瘤整块切除。PIN被肿瘤包绕；予以保留并小心地从肿瘤中游离出来。神经鞘作为切除切缘。总之，我们报告了一例罕见的旋后肌肌内黏液瘤病例。鉴于其位置，在切除手术过程中应格外注意定位PIN并避免损伤周围结构。
