Tenosynovial giant cell tumors in unusual locations detected by positron emission tomography imaging confused with malignant tumors: report of two cases.
Tenosynovial giant cell tumors in unusual locations detected by positron emission tomography imaging confused with malignant tumors: report of two cases.
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DOI：
10.1186/s12891-016-1050-7
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发表时间：
2016-04-26
影响因子：
2.3
通讯作者：
Tsuchiya H
中科院分区：
文献类型：
--
作者：
Takeuchi A;Yamamoto N;Hayashi K;Miwa S;Takahira M;Fukui K;Oikawa T;Tsuchiya H
腱鞘巨细胞瘤（T-GCT）是发生于滑膜、滑囊或腱鞘的良性滑膜肿瘤。它可以是关节内或关节外的，也可以是局限性或弥漫性的。弥漫性T-GCT被认为是局部侵袭性的。正电子发射断层扫描（PET）与氟-18氟脱氧葡萄糖与计算机断层扫描（FDG PET/CT）被广泛用于区分恶性和良性肿瘤，并检测远处转移。然而，FDG PET/CT受到假阳性结果的限制。在这项研究中，我们提出了两例T-GCT的发展在不寻常的位置，并与恶性肿瘤混淆。最终诊断经组织学证实为T-GCT。案例1.一名45岁的日本女性，患有左侧脉络膜黑色素瘤和PET扫描证实的第一颈椎（C1）椎板附近的异常病变（最大标准化摄取值[SUVmax] = 9.9 g/ml）。颈部MRI还检测到邻近C1椎板的软组织肿块（14.6 × 7.7 × 7 mm）。脉络膜黑色素瘤采用重碳离子放射治疗。虽然C1软组织肿瘤的大小保持不变，CT引导下活检证实了颈部肿块的诊断为T-GCT。案例2.一名15岁的日本男性，患有多发性1型神经纤维瘤病，在检查纵隔软组织肿块时，FDG PET/CT偶然发现关节外髋关节的软组织肿块（26.1 × 24.7 × 11.5 mm）。纵隔病变的SUVmax为2.6 g/ml，髋关节病变的SUVmax为12.8 g/ml。因此，必须与恶性肿瘤（如恶性外周神经鞘瘤）进行鉴别。行开放性活检，冷冻切片诊断为T-GCT。切除肿瘤，最终的组织学诊断证实了T-GCT。T-GCT可显示高FDG摄取，这可能与恶性肿瘤混淆。虽然MRI结果和位置可能有助于T-GCT的诊断，但仔细评估是必须的，特别是在不寻常的位置。
A tenosynovial giant cell tumor (T-GCT) is a benign synovial tumor arising from the synovium, bursae, or tendon sheath. It can be intra- or extra-articular and localized or diffuse. Diffuse T-GCT is considered as a locally aggressive. Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose with computed tomography (FDG PET/CT) is widely used to differentiate malignant from benign tumors and to detect distant metastasis. However, FDG PET/CT is limited by false-positive findings. In this study, we present two cases of T-GCT that developed in unusual locations and were confused with malignant tumors. The final diagnoses were histologically confirmed as T-GCTs. Case 1. A 45-year-old Japanese female presented with a left choroidal melanoma and an abnormal lesion adjacent to the first cervical (C1) lamina confirmed by a PET scan (maximum standardized uptake value [SUVmax] = 9.9 g/ml). MRI of the neck also detected a soft tissue mass (14.6 × 7.7 × 7 mm) adjacent to the C1 lamina. The choroidal melanoma was treated by heavy carbon ion radiotherapy. Although the size of the C1 soft tissue tumor remained unchanged, a CT-guided biopsy confirmed the diagnosis of the neck mass as a T-GCT. Case 2. A 15-year-old Japanese male with multiple type 1 neurofibromatosis presented with a soft tissue mass (26.1 × 24.7 × 11.5 mm) of the extra-articular hip joint that was coincidentally detected by FDG PET/CT during examination of a mediastinal soft tissue mass. SUVmax of the mediastinal lesion was 2.6 g/ml and of the hip lesion was 12.8 g/ml. Thus, differentiation from a malignant tumor, such as a malignant peripheral nerve sheath tumor, was necessary. An open biopsy was performed, and the frozen section was diagnosed as T-GCT. The tumor was excised, and the final histological diagnosis confirmed T-GCT. T-GCT can show high FDG uptake, which might be confused with malignancy. Although MRI findings and location might help in the diagnosis of a T-GCT, careful assessment is mandatory, especially in unusual locations.