Iijima Yoshihito, Nakajima Yuki, Kinoshita Hiroyasu, Kurihara Yasuyuki, Nishimura Yu, Iizuka Toshihiko, Akiyama Hirohiko, Hirata Tomomi
Division of Thoracic Surgery, Saitama Cancer Center, 780 Komuro, Ina-machi, Kita adachi-gun, Saitama 362-0806, Japan.
Division of Thoracic Surgery, Saitama Cancer Center, 780 Komuro, Ina-machi, Kita adachi-gun, Saitama 362-0806, Japan.
Int J Surg Case Rep. 2020;68:115-118. doi: 10.1016/j.ijscr.2020.02.034. Epub 2020 Feb 19.
Sclerosing thymoma (ST) is an extremely rare disease with less than 20 cases ever been described. Here, we present a case of sclerosing thymoma that was followed up as mediastinal goiter for eight years.
A 77-year-old man was presented with a superior mediastinal tumor. The patient was asymptomatic and not affected by myasthenia gravis. Computed tomography showed a well-defined superior mediastinal tumor whose size had regressed over time. Ultrasonography-guided core-needle biopsy revealed type B1 to B2 thymoma, and total-thymectomy was performed. Histopathologically, most of the tumor showed hyalinization and sclerosis, and slight signs of type AB thymoma were found at the tumor's periphery. The patient was diagnosed with ST. No evidence of recurrence was observed 12 months following surgery.
Since sclerosing thymoma is mostly composed of fibrous tissue, small specimens such as needle biopsies do not contain tumor cell nests and are difficult to confirm. Complete resection is currently the most common treatment for ST. Spontaneous regression of ST has been reported; however, the mechanisms involved have not yet been elucidated.
This rare case of sclerosing thymoma is an unusual case since it has follow up information for an eight year period due to the misdiagnosis of goiter. The follow up visits showed significant regression of the tumor over the eight year period without treatment; however, the etiology of sclerosis and regression remain unknown. The patient was treated by thymectomy with no recurrence after 12 months.
硬化性胸腺瘤（ST）是一种极为罕见的疾病，迄今报道的病例不足20例。在此，我们报告一例硬化性胸腺瘤，该病例曾被误诊为纵隔甲状腺肿长达八年。
一名77岁男性患者，因上纵隔肿瘤前来就诊。患者无症状，也未受重症肌无力影响。计算机断层扫描显示上纵隔有一个边界清晰的肿瘤，其大小随时间有所缩小。超声引导下的粗针活检显示为B1至B2型胸腺瘤，遂行胸腺全切术。组织病理学检查显示，肿瘤大部分区域呈现透明变性和硬化，肿瘤周边可见轻微的AB型胸腺瘤迹象。该患者被诊断为硬化性胸腺瘤。术后12个月未发现复发迹象。
由于硬化性胸腺瘤主要由纤维组织构成，像针吸活检这样的小标本中不含肿瘤细胞巢，难以确诊。目前，完整切除是治疗硬化性胸腺瘤最常用的方法。已有报道称硬化性胸腺瘤可自发消退，但其相关机制尚未阐明。
这例罕见的硬化性胸腺瘤是一个特殊病例，因其因甲状腺肿误诊而有长达八年的随访信息。随访显示，在未接受治疗的八年期间肿瘤显著缩小，然而，硬化和消退的病因仍不清楚。该患者接受了胸腺切除术，术后12个月未复发。
