CASE HISTORY
一名35岁的肥胖男性被录取为Tri-Service综合医院(台北,台湾)进一步检查在医学检查期间获得的胸部射线照片的异常不透明度。病人已经无症状,从未接受过任何用类固醇治疗。体检是不起眼的。实验室数据,包括完整的血统和肿瘤标志物,在正常限制范围内。血清学测试的异常实验室结果如下:胆固醇225 mg·DL−1;天冬氨酸氨基转移酶45 IU·L.−1;和丙氨酸氨基转移酶61 IU·L.−1。在图1中可以看到初始胸部X线和计算机断层扫描(CT)扫描⇓and 2⇓, respectively.
The patient underwent mass resectionvia胸骨术。传播过大的肿瘤胸腺(第一个标本)in toto。However, the resected tumour was not comparable in size to the lesion discovered on CT imaging. A decision was made to incise the mediastinal pleura for confirmation of the pre-operative CT findings. A sizeable, whitish soft mass (the second specimen) was uncovered in the mediastinum, adjacent to the aortic arch. No attachment was found between the tumour and either the bronchial tree or oesophagus. Surgical excision of the tumour was performed. The histological findings of both specimens are shown in figures 3⇓and 4⇓。
在转动页面之前,解释患者的历史,胸部X线片,计算机断层摄影扫描和显微照片,并建议诊断。
INTERPRETATION
胸部radiograph
The initial chest radiograph (fig. 1⇑) revealed a mass lesion superimposed on the aortic arch.
Computed tomography scan
On unenhanced CT scan, the mass appeared well circumscribed, oval and had a soft-tissue attenuation of about 35–60 HU. It was located in the left anterior mediastinal compartment and was adjacent to both the aortic arch and the thymus. After injection of contrast media (fig. 2⇑), the mass itself was not enhanced.
组织病理学图片
在切除的胸腺肿瘤(第一个样品)的病理研究中,其总特征在稠度和灰黄色中柔软。肿瘤的尺寸测量8×5×1.5cm,重64.2克。组织病理学检查(图3⇑) revealed that the tumour consisted mainly of mature adipose tissue interspersed with islands of non-neoplastic thymic tissue containing Hassall's corpuscles, which had immunoreactivity for AE 1/3 (pan-cytokeratin).
第二次样品的总特征是一个ovoid shape, soft consistency and grey colour. The tumour was found to be filled with viscous, jelly-like fluid after dissection. On histopathological evaluation (fig. 4⇑), it was found to be a cystic tumour with pseudo-stratified ciliated columnar epithelial lining.
诊断:胸腺素瘤,具有共存的纵隔前述囊肿。
CLINICAL COURSE
During 6 months of follow-up, clinical evaluation and interval chest radiography were all stable. A repeat CT scan of the chest did not show any sign of recurrence. The patient continues to be well to the present day.
讨论
Foregut cysts are congenital lesions resulting from aberrant development of the primitive foregut, which originate from the endoderm1,2,在妊娠的第4-8周之间2。Radiograph and CT scan characteristics of foregut cysts are well defined. On chest radiography, they appear as spherical, well-circumscribed, homogeneous masses1。On CT scans, foregut cysts manifest as spherical masses of either water or soft-tissue attenuation1,3,4。The masses, with the exception of the capsule, do not show contrast enhancement after injection of contrast media3。When foregut cysts reveal soft-tissue attenuation masses on CT scans, differentiation from solid lesions can be more problematic. Magnetic resonance imaging can be useful for suggesting the true cystic nature of the lesion3。Foregut cysts are most often located in the hilum or middle mediastinum5。在当前情况下,前述囊肿似乎具有软组织衰减并位于前纵隔型中。在CT扫描上的这种罕见特性表明首先诊断胸腺病变。
Thymolipoma are rare tumours consisting of mature adipose tissue with interspersed islands of non-neoplastic thymic tissue6。患有胸腺胶质瘤的患者可以长期无症状。大多数病例是常规胸部射线照相或尸检的偶然结果7。On CT scans, thymolipomas demonstrate a mixture of fat and soft-tissue attenuation8。
一个ccording to previous studies, thymic primordial appear late in the sixth week of gestation and originate from the endoderm9,10。The mean weight of a normal thymus is no larger than 30–40 g until puberty. A gradual process of involution then occurs throughout adulthood, and the weight of the thymus is reduced to 5–25 g10。一个t surgery, the present patient's sizeable tumoural thymus was resected. The pathological morphology supported the diagnosis of thymolipoma, which weighed 64.2 g. To the present authors' knowledge, this case presents the second smallest thymolipoma documented in the literature (the smallest was 63 g11). The pathogenesis of thymolipoma is unclear and has been the subject of much speculation. Up to now, four theories have been proposed, but none has been solidly proved12。
What is most interesting about the present case is that abnormal embryogenesis is the cause of the foregut cyst, and/or thymolipoma. Embryologically, both the foregut and the thymus have the common origin of the endoderm2,9。在胚胎发生的发展中,前述囊肿出现在妊娠期的第4周和8周之间2。Simultaneously, the thymic primordia also appears in the sixth week of gestation as ventral outgrowths of the third pharyngeal pouches10。根据胚胎源性起源的相似性,以及相似的妊娠期,本作者怀疑常见期间内胚层的缺陷可能导致前述囊肿和/或胸腺异常,包括潜力胸腺胶质瘤的原因。现在的案例是这种理论的一个例子。
对于目前的作者的知识,以前没有在文献中描述与胸腺瘤相关的前述囊肿。本文呈现的情况特别有趣,因为它是第一个与胸腺瘤共存的前述囊肿的案例。因此,作者已经创造了术语“前胸部异常”代表这种情况。
Due to the asymptomatic characteristic of thymolipoma, its disclosure is uncommon. The present authors believe that many more cases exist that embody their theory.
- ReceivedDecember 3, 2005.
- 一个ccepted2006年2月22日。
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