Abstract：
BACKGROUND: High-grade transformation Adenoid cystic carcinoma (HGT-AdCC) of the parotid gland is a rare transformation noted in slow growing low grade AdCC. Perineural invasion and spread is an important feature of this tumor. Temporal bone involvement is rare. A total of only 10 cases of HGT-AdCC in parotid gland has been reported in literature so far predominantly in the elderly with peak incidence in 5th-6th decade.
METHODS: We present a young lady of HGT-AdCC of right parotid gland with temporal bone involvement in the form of isolated perineural invasion (PNI) of facial nerve till the tympanic segment. She underwent right radical parotidectomy with modified radical neck dissection with modified lateral temporal bone resection and pectoralis major myocutaneous flap reconstruction. Histopathological examination revealed both low- and high-grade areas. Sections from facial nerve showed tumor invasion.
CONCLUSIONS: The radiological features of isolated perineural spread in intratympanic part of facial nerve can be easily missed if not specifically looked for. Every attempt should be made preoperatively and intraoperatively to determine the complete extent of the tumor for adequate disease clearance. A combined clinico-radiological approach aided by histopathology examination helps in early detection of this carcinoma and in better patient management.
METHODS: We present a young lady of HGT-AdCC of right parotid gland with temporal bone involvement in the form of isolated perineural invasion (PNI) of facial nerve till the tympanic segment. She underwent right radical parotidectomy with modified radical neck dissection with modified lateral temporal bone resection and pectoralis major myocutaneous flap reconstruction. Histopathological examination revealed both low- and high-grade areas. Sections from facial nerve showed tumor invasion.
CONCLUSIONS: The radiological features of isolated perineural spread in intratympanic part of facial nerve can be easily missed if not specifically looked for. Every attempt should be made preoperatively and intraoperatively to determine the complete extent of the tumor for adequate disease clearance. A combined clinico-radiological approach aided by histopathology examination helps in early detection of this carcinoma and in better patient management.
摘要：
背景：腮腺高级别转化腺样囊性癌（HGT-AdCC）是一种罕见的转化，在缓慢增长的低级别AdCC中发现。神经周浸润和扩散是该肿瘤的重要特征。颞骨受累很少见。迄今为止，文献中仅报道了10例腮腺HGT-AdCC，主要发生在老年人中，其发病率在第5-6个十年达到峰值。
方法：我们介绍了一名右腮腺HGT-AdCC的年轻女士，颞骨受累，其形式是面神经孤立性侵犯（PNI），直至鼓段。她接受了右腮腺根治性切除术，改良根治性颈清扫术，改良颞骨外侧切除术和胸大肌肌皮瓣重建。组织病理学检查显示了低级和高级区域。面神经切片显示肿瘤浸润。
结论：如果不明确查找，很容易错过孤立的神经周扩散在面神经鼓室部分的放射学特征。应在术前和术中进行一切尝试，以确定肿瘤的完整范围，以清除足够的疾病。由组织病理学检查辅助的联合临床放射学方法有助于早期发现这种癌并更好地管理患者。
方法：我们介绍了一名右腮腺HGT-AdCC的年轻女士，颞骨受累，其形式是面神经孤立性侵犯（PNI），直至鼓段。她接受了右腮腺根治性切除术，改良根治性颈清扫术，改良颞骨外侧切除术和胸大肌肌皮瓣重建。组织病理学检查显示了低级和高级区域。面神经切片显示肿瘤浸润。
结论：如果不明确查找，很容易错过孤立的神经周扩散在面神经鼓室部分的放射学特征。应在术前和术中进行一切尝试，以确定肿瘤的完整范围，以清除足够的疾病。由组织病理学检查辅助的联合临床放射学方法有助于早期发现这种癌并更好地管理患者。
