Purpose: To evaluate the clinical and histopathological characteristics of silent skin squamous cell carcinomas (SCC) with invasion routes to the orbit.
Methods: Retrospective case studies. Clinical records and histopathological material, therapy and complications were evaluated, together with MRI imaging analyses and literature review on the anatomy of the lateral orbital wall in relation to the zygomatico-temporal nerve channel.
Results: Two recent cases of metastatic SCC from het lateral zygomatic region to het orbit are reported. Originally the skin tumors of the first case was diagnosed as benign, but a review of the pathology of these skin tumors showed an invasive SCC. The second case was diagnosed as an atypical SCC. Analysis of possible invasion routes, using both computer tomography (CT) and magnetic resonance imaging (MRI), indicated neither skin nor bone involvement. However, the lateral temporal fossa near the entrance of the zygomatico-temporal channel showed small tumors and pseudo-cysts. The original skin tumor specimens did not show malignant tissue in the surgical margins nor intra- or perineural invasion.
Conclusions: Because the course of the zygomatico-temporal nerve bundle was exactly in line with the original skin tumor, the channel and the orbital tumors, this route should be considered when malignant orbital tumors have a history of or a relation with a periorbital skin-tumor.
Keywords: Orbital tumor; skin malignancy temporal fossa; squamous cell carcinoma. Zygomatemporal extension route.