Some mistake erythema of the tympanic membrane as being caused by blood in the middle ear. However, while we associate a bright red color with blood, the type of blood that accumulates in the middle ear is generally capillary or venous blood, occurring as a result of fractures or barotrauma. Blood in the middle ear will typically appear as a purple tympanic membrane.
Arterial bleeding in the middle ear is extremely rare and would generally be caused by a carotid artery laceration or aneurysm rupture. This phenomenon would invariably lead to bleeding from the nose and mouth, as the blood would be under pressure and track through the Eustachian tube into the nasopharynx and oropharynx, leading to rapid demise.
Finally, erythema of the tympanic membrane can result from a mass behind the tympanic membrane. The most common middle ear tumor is a glomus tumor. When a glomus tumor arises from the glomus bodies of the middle ear, which lie on the promontory of the cochlea, it is called a glomus tympanicum.
A glomus tumor can also arise from the dome of the jugular bulb, which is close to the middle ear. These tumors can expand silently and will break through the floor of the middle ear, becoming visible behind the tympanic membrane. This tumor, termed glomus jugulare, can fill the middle ear and be indistinguishable from a glomus tympanicum on examination.
During pneumatic otoscopy, air pressure on the tympanic membrane can cause blanching of the tumor on examination, which is called Brown's sign. A glomus tumor generally pulsates behind the tympanic membrane, as is shown in the accompanying video (see box). This patient had a glomus jugulare tumor.
Glomus jugulare tumors are generally diagnosed using a combination of CT and MRI scanning. On CT imaging, the tumor is seen as infiltrating the bone surrounding the jugular bulb (the top-most portion of the jugular vein).
Due to their vascularity, the tumors take up contrast intensely on MRI. Glomus tumors are generally benign; aggressive/malignant forms do occur but are uncommon.
The treatment of glomus jugulare tumors is generally surgical resection. In recent years, there has been a trend toward the use of stereotactic radiosurgery in some patients.
Due to the proximity of the lower cranial nerves (IX to XI), surgery for total resection of these tumors has an increased likelihood of injury to some of these nerves, which can cause problems with swallowing or voice.
Stereotactic radiosurgery aims to stop further growth of the tumor but does not cause the tumor to disappear. Sometimes patients are treated with a combination of surgery and radiosurgery, depending on the extent and location of the tumor.
CLINICAL CONSULTATION VIDEO
Read this month's column on glomus tumor by Hamid R. Djalilian, MD, and then watch the video to see the mass in the middle ear and its pulsation—only available in the December iPad issue.
To see the video, download The Hearing Journal app for free today at http://bit.ly/AppHearingJ.
Read past Clinical Consulation columns in a special collection on the HJ website: http://bit.ly/HJClinicalConsultation.© 2013 by Lippincott Williams & Wilkins, Inc.