[Right maxillary sinus epidermoid cyst huge: report of 1 case].

Dermoid cysts occur in the maxillary sinus mucosa were rare. Patient's CT showed: maxillary sinuses Sinus cavity expansion, sinus wall thinning. The inside of the sinus wall disappeared, the maxillary sinus filled with soft tissue mass shadow. Bacterial culture: Staphylococcus aureus. Pathological report: a very small a mount of scattered broken squamous epithelium and keratosis, no atypia cells. Lesions consistent with epidermoid cyst. Patients with epidermoid cysts, formated probably in the process of embryonic development, the reasons of rapid growth may be considered for inflammatory stimulation.