A case of mucoepidermoid carcinoma of the parotid gland; unusual progression to the external auditory canal via Santorini’s fissures

Here we report a case of mucoepidermoid carcinoma of the parotid gland accompanied by invasion through an unusual route. A 46-year-old female visited our department complaining of a growth in the external auditory canal and a purulent discharge. She had no swelling in her parotid region. Repeated biopsies of the external ear revealed inflammatory granulations and they made it difficult to point out the neoplasm. Contrast enhanced CT and MRI findings showed a solid tumor of the parotid gland that extended to the cranial side of the gland. Finally, a low-grade mucoepidermoid carcinoma that had originated in the upper pole of the parotid gland had progressed to the external auditory canal via "Santorini's fissures," which is a notch in the cartilage of the auditory meatus. Both otolaryngologists and pathologists should pay attention to this kind of unusual route taken by a parotid gland tumor invasion.