Osseous Hamartoma Arising from the Eustachian Tube
A 56-year-old male patient presented with right aural fullness and nasal obstruction that had been evident for three years. He had no juvenile history of nasal disease or otitis media. At the first admission, the secretory otitis media (SOM) in the right ear was investigated, and a solid, smooth and poorly mobile tumor was detected in the posterior part of the nasal cavity and nasopharynx (). Initial diagnosis of a transnasal biopsy sample suggested fibroma. Computed tomography (CT) examination showed that the tumor occupied the nasopharynx, and a high-intensity shadow was evident within it (, and ). Although CT was unable to reveal the origin of the tumor, the high-intensity shadow extended in the direction of the ET () and thus the tumor was thought to have arisen from the ET. Magnetic resonance imaging (MRI) showed that the tumor consisted of heterogeneous components with T1 enhancement (), and that the inside of the tumor appeared more contrasted with T2 enhancement (). The T2 enhanced image showed a smooth line of the nasopharyngeal mucosa, suggesting no tumor invasion in the nasopharynx. Enhancement with intravenous contrast medium revealed no remarkable features by both CT and MRI.\nUnder a preoperative diagnosis of nasopharyngeal tumor possibly involving the Eustachian tube, partial resection of the nasopharyngeal tumor was performed by transnasal endoscopic surgery to obtain a definitive diagnosis and to relieve the nasal obstruction. A hard mass with a smooth surface was seen to arise from the pharyngeal ostium of the ET (). The mass was reduced piecemeal using scissors and sharp forceps, taking care to preserve the normal mucosa of the nasopharynx. The tumor was not attached to the nasal and pharyngeal mucosa and protruded into the ET. However, its point of origin could not be detected precisely because the surgical devices were unable to reach the inside of the ET. Part of the tumor in the ET therefore remained, and a tympanostomy tube was inserted into the right ear to resolve the SOM. Pathological examination showed that the tumor consisted of bony tissue, fat cells and proliferated fibroblasts, and was diagnosed as osseous hamartoma arising from the ET (). Ten months after the reduction surgery, the tumor was not markedly enlarged (). The nasal obstruction, right aural fullness and conductive hearing loss that were evident on initial presentation were diminished after the surgery.