J Am Vet Med Assoc. 2020 Jul 15;257(2):183-188. doi: 10.2460/javma.257.2.183.
A 10-year-old 7-kg (15.4-lb) neutered male Shih Tzu was referred for evaluation because of a sudden onset of dullness and intermittent vomiting of 1 to 2 weeks' duration. Two days prior to evaluation, clinical signs had worsened and 1 seizure was reported.
A 3.5 × 2.5-cm soft, dome-shaped mass of the right occipital region of the head was noted on physical examination. Radiography and CT confirmed the presence of the mass and indicated its intra- and extracranial expansion. The MRI images showed compression of the cerebellum by the mass, with distinct margins of hypointensity on both T1- and T2-weighted images.
Surgery was performed, and the mass was completely excised. The dog had mild ataxia, hypermetria, and head tremors after surgery. Histologic examination of the mass yielded a diagnosis of intradiploic epidermoid cyst. On examination 3 weeks after surgery, the previous neurologic signs had resolved. On examination 25 months after surgery, the dog remained free of clinical signs.
The present report described the clinical signs, diagnostic imaging results, and successful surgical removal of an intradiploic epidermoid cyst in a dog. Long-term prognosis may be good with complete removal of intradiploic epidermoid cysts in dogs.
一只 10 岁、7 公斤（15.4 磅）已绝育的雄性西施犬，因突发精神沉郁和间歇性呕吐 1 至 2 周而被转介进行评估。在评估前 2 天，临床症状恶化，并报告了 1 次癫痫发作。
体格检查时发现头部右侧枕区有一个 3.5×2.5 厘米的柔软、圆顶状肿块。放射摄影和 CT 确认了肿块的存在，并表明其在颅内和颅外的扩张。MRI 图像显示肿块对小脑的压迫，在 T1 和 T2 加权图像上均有明显的低信号边界。
进行了手术，完全切除了肿块。手术后，狗出现轻度共济失调、过度伸展和头部震颤。肿块的组织学检查诊断为骨内表皮样囊肿。手术后 3 周检查时，先前的神经症状已缓解。手术后 25 个月检查时，狗仍无临床症状。
本报告描述了一只狗的临床症状、诊断成像结果和骨内表皮样囊肿的成功手术切除。如果完全切除狗的骨内表皮样囊肿，预后可能良好。
