One case of misdiagnosis of giant cell tumor of the tendon sheath
腱鞘巨细胞瘤误诊1例

摘要

目的 报告1例足趾腱鞘巨细胞瘤的误诊病例，分析其临床特征、影像学表现及鉴别诊断要点。方法 22岁男性患者，既往痛风病史，因“右足第2趾包块1年余”就诊。首次就诊查体示包块1.5*1.0 cm，质韧、压痛，局部红肿，实验室检查血尿酸升高，超声提示低回声肿块，误诊为骨巨细胞瘤，MRI提示软组织肿胀，炎症可能。临床按“皮下肿物、高尿酸血症”对症治疗。一年后复查，肿块增大至2.0*2.0 cm，疼痛加剧。超声探及大小约2.83*2.23*1.75 cm低回声包块，内见粗大钙化及丰富低阻血流，与趾伸肌腱分界清，提示腱鞘巨细胞瘤可能。结果 肿块行手术切除，病理确诊为腱鞘巨细胞瘤，复诊超声与病理结果相符。结论 腱鞘巨细胞瘤易因不典型超声表现及痛风病史干扰导致误诊，需注意与腱鞘纤维瘤、色素沉着绒毛结节性滑膜炎、骨巨细胞瘤及痛风石鉴别。

Abstract

Objective To report a misdiagnosed case of giant cell tumor of the tendon sheath of the toe, and analyze its clinical characteristics, imaging manifestations and key points of differential diagnosis.
Methods A 22-year-old male patient with a previous history of gout presented with a "lump in the second toe of the right foot for more than one year". First visit physical examination showed a lump of 1.5*1.0 cm, tough and tender, with local redness and swelling. Laboratory tests indicated elevated blood uric acid levels. Ultrasound suggested a hypoechoic lump, which was misdiagnosed as giant cell tumor of bone. MRI suggested soft tissue swelling and possible inflammation. Clinically, symptomatic treatment is given based on "subcutaneous masses and hyperuricemia". During the re-examination after one year, the lump increased to 2.0*2.0 cm, and the pain intensified. Ultrasound revealed a hypoechoic lump of 2.83*2.23*1.75 cm, with coarse calcification and abundant low-resistance blood flow observed inside. The boundary with the extensor digital-toes tendon was clear, suggesting the possibility of a giant cell tumor of the tendon sheath. Result The lump was surgically removed. The pathological diagnosis was giant cell tumor of the tendon sheath. The follow-up ultrasound results were consistent with the pathological findings.
Conclusion   Giant cell tumor of the tendon sheath is prone to misdiagnosis due to atypical ultrasound manifestations and interference from a history of gout. Attention should be paid to differentiating it from fibroma of the tendon sheath, pigmented villonodular synovitis, giant cell tumor of bone and tophi.