Objective: To establish an animal model with malignant tumor in the skull base-infratemporal region, and to explore the role of iodine staining technique in identifying tumor tissues with Micro-CT data.
Methods: Sedation anesthesia was carried out on 12 BABL/c nude mice using inhaled isoflurane, and then WSU-HN6 cells that cultured and immortalized from human tongue squamous cell carcinoma were injected into the right infratemporal fossa via the submandibular area. The procedure was carried out under ultrasonographic guidance. The nude mice were sacrificed after 3 weeks observation. The head specimens were fixed and scanned by Micro-CT, and repeated scans were performed after staining with 3.75% compound iodine solution. Following decalcification in 20% EDTA for 2-4 weeks, the head specimens were embedded and sectioned. Hematoxylin and eosin staining and Pan-Keratin immunohistochemical staining were carried out. Bright-field microscopy and stereomicroscopy were used to visualize. The Micro-CT data were analyzed using iPlan software (Brainlab).
Results: Non-traumatic ultrasonography was used to guide HN-6 cells injection and confirm skull-base tumor formation in all the animals. Ultrasonographic guidance reduced the risk of cervical vessel injury when transferring tumor cells into the skull base space. An obvious asymmetrical appearance was detected via ultrasonography 3 weeks after tumor cell injection. The Micro-CT analysis showed that the bone was obviously damaged on the right side of the skull base, but the soft tissue image was unrecognizable. After four days staining with compound iodine solution, the morphology of the tumor and surrounding soft tissue could be clearly identified. Hematoxylin and eosin staining showed the tumor formation of the right infratemporal fossa region accompanied by bone destruction. Human keratin immunohistochemical staining showed that the tumor tissue originated from human squamous cell carcinoma, and the polynuclear osteoclasts could be seen at the margin of the skull base bone resorption.
Conclusion: The animal model with malignant tumor in the skull base-infratemporal region could be successfully established via submandibular injection under ultrasound-guidance. Bone changes of the skull were easily observed on Micro-CT, but the tumor counter was not able to be distinguished from surrounding soft tissue. The 3.75% compound iodine staining of the head specimen could help discern the tumor and surrounding soft tissue in more details.
目的: 建立颅底-颞下区恶性肿瘤动物模型，探索碘液浸染技术在Micro-CT图像中识别肿瘤组织的作用。
方法: 对12只BABL/c裸鼠采用异氟烷吸入镇静麻醉，在小动物超声系统引导下经颌下区注射头颈鳞状细胞癌WSU-HN6细胞至右侧颞下窝。观察3周后解剖头颅标本，用4%多聚甲醛固定，并行Micro-CT扫描，3.75%复方碘液浸染后重复扫描。将头部标本包埋、切片，进行苏木精-伊红染色和免疫组织化学染色分析肿瘤形成情况。
结果: 经Micro-CT分析发现颅骨有明显破坏，但无法辨别肿瘤组织；经3.75%复方碘液浸染后，在Micro-CT阅读软件中可以清晰观察肿瘤及周围软组织形态。经苏木精-伊红染色和免疫组织化学染色分析证实，颅底-颞下区形成鳞状细胞癌，同时伴有明显颅骨破坏。
结论: 采用颌下注射方式可以成功构建颅底-颞下区肿瘤动物模型；Micro-CT可以观察到颅骨骨质改变，采用复方碘液浸染后有利于观察肿瘤及周围软组织结构。
Keywords: Compound iodine solution; Nude mice; Skull base; Tumor.