Abstract：
BACKGROUND: White epidermoid cysts (WECs) are a rare type of epidermoid cyst with atypical radiological features. The epidemiological aspects and mechanisms of their onset remain unknown. Herein, the authors report a unique case of WEC transformation from a typical epidermoid cyst after stereotactic radiosurgery (SRS), confirmed by radiological and pathological findings.
METHODS: The case involved a 78-year-old man with a history of 2 surgeries for a left cerebellopontine angle typical epidermoid cyst 23 years earlier and SRS using the CyberKnife for recurrent trigeminal neuralgia (TN) 14 years earlier. The tumor with high intensity on T1-weighted imaging, low intensity on T2-weighted imaging, without restriction on diffusion-weighted imaging had gradually enlarged after SRS. Therefore, a salvage surgery was performed via a left suboccipital craniotomy, and the intraoperative findings showed a cyst with a brown, viscous liquid component, consistent with those of WECs. Histopathologically, keratin calcification and hemorrhage were identified, leading to a diagnosis of WEC. The postoperative course was uneventful, and the TN resolved. No tumor recurrence was recorded at 2 years postoperatively.
CONCLUSIONS: To the best of the authors\' knowledge, this is the first world case of WEC transformation from a typical epidermoid cyst after SRS, confirmed by radiological and pathological findings. Radiation effects could have been involved in this transformation.
METHODS: The case involved a 78-year-old man with a history of 2 surgeries for a left cerebellopontine angle typical epidermoid cyst 23 years earlier and SRS using the CyberKnife for recurrent trigeminal neuralgia (TN) 14 years earlier. The tumor with high intensity on T1-weighted imaging, low intensity on T2-weighted imaging, without restriction on diffusion-weighted imaging had gradually enlarged after SRS. Therefore, a salvage surgery was performed via a left suboccipital craniotomy, and the intraoperative findings showed a cyst with a brown, viscous liquid component, consistent with those of WECs. Histopathologically, keratin calcification and hemorrhage were identified, leading to a diagnosis of WEC. The postoperative course was uneventful, and the TN resolved. No tumor recurrence was recorded at 2 years postoperatively.
CONCLUSIONS: To the best of the authors\' knowledge, this is the first world case of WEC transformation from a typical epidermoid cyst after SRS, confirmed by radiological and pathological findings. Radiation effects could have been involved in this transformation.
摘要：
背景：白色表皮样囊肿（WECs）是一种罕见的表皮样囊肿，具有不典型的放射学特征。其发病的流行病学方面和机制仍然未知。在这里，作者报告了立体定向放射外科（SRS）后典型表皮样囊肿WEC转化的独特病例，通过放射学和病理学检查证实。
方法：该病例涉及一名78岁的男性，23年前有2例左桥小脑角典型表皮样囊肿手术史，14年前使用射波刀进行SRS治疗复发性三叉神经痛（TN）。在T1加权成像上具有高强度的肿瘤，低强度的T2加权成像，无限制扩散加权成像在SRS后逐渐增大.因此,通过左枕下开颅术进行了抢救手术，术中发现有一个棕色囊肿，粘性液体成分，与WEC的一致。组织病理学,确定了角蛋白钙化和出血，导致WEC的诊断。术后进展顺利，TN解决了。术后2年无肿瘤复发。
结论：据作者所知，这是世界上首例典型表皮样囊肿经SRS后WEC转化的病例,通过放射学和病理学检查证实。辐射效应可能参与了这种转变。
方法：该病例涉及一名78岁的男性，23年前有2例左桥小脑角典型表皮样囊肿手术史，14年前使用射波刀进行SRS治疗复发性三叉神经痛（TN）。在T1加权成像上具有高强度的肿瘤，低强度的T2加权成像，无限制扩散加权成像在SRS后逐渐增大.因此,通过左枕下开颅术进行了抢救手术，术中发现有一个棕色囊肿，粘性液体成分，与WEC的一致。组织病理学,确定了角蛋白钙化和出血，导致WEC的诊断。术后进展顺利，TN解决了。术后2年无肿瘤复发。
结论：据作者所知，这是世界上首例典型表皮样囊肿经SRS后WEC转化的病例,通过放射学和病理学检查证实。辐射效应可能参与了这种转变。
