Intractable yawning associated with mature teratoma of the supramedial cerebellum.

Yawning occurs in various conditions such as hypoxia, epilepsy, and sleep disorders including sleep apnea. Intractable yawning associated with a brain tumor has been rarely reported. A 19-year-old woman presented with intractable yawning. Magnetic resonance imaging showed a tumor in the supramedial cerebellum that compressed the dorsal side of the midbrain and upper pons. After subtotal removal of the tumor, the yawning completely disappeared. Postoperative MRI showed resolution of compression of the brainstem. The tumor was histologically diagnosed as a mature teratoma. The present case suggested that the intractable yawning resulted from the tumor compressing the dorsal side of the junction between the midbrain and pons.