Paraganglioma
A paraganglioma is a tumor that originates from cells called paraganglia found in the middle ear:
*Glomus tympanicum tumors are small sized tumors originating in the middle ear.
*Glomus jugulare arise from paraganglia in or around the jugular bulb, and as they grow they occlude this venous structure.
Complications for Paraganglioma
Paraganglioma usually develop a rich blood supply from surrounding blood vessels. These tumors produce substances that act on local blood vessels causing them to grow toward the tumor. Tumors that originate from the jugular bulb, or glomus jugulare tumors, can grow to fill the entire bulb, thereby effectively blocking blood flow to the heart from that side of the brain. Because of the tumor’s incremental growth, blood flow from the brain is gradually diverted toward the opposite sigmoid sinus and jugular bulb. The opposite venous system becomes larger to accommodate the increased blood flow.
Typically, paragangliomas that have not previously been treated receive their blood supply from branches of the external carotid artery. The common carotid artery is a vessel that allows oxygenated blood to flow from the heart to the region of the head and neck.
On occasion, paragangliomas can also produce and secrete proteins into the bloodstream that can lead to high blood pressure, fast heart rate, palpitations, sweating, and/or diarrhea. The breakdown products of these proteins can be detected prior to any treatment by collecting and checking the urine. Manipulation of the tumor during surgery may cause hypertension.
Complications of GlomusTympanicum Tumors
A conductive hearing loss occurs when the tumor impairs the normal vibration of the ossicles (bones) behind the eardrum. A nerve-type (sensorineural) hearing loss and/or dizziness can result in an unusual circumstance where the tumor has invaded the inner ear.
Complications of Glomus Jugulare Tumors
A conductive hearing loss occurs when the tumor impairs the normal vibration of the ossicles (bones) behind the eardrum. A nerve-type (sensorineural) hearing loss and/or dizziness can result in an unusual circumstance where the tumor has invaded the inner ear.
The nerves that control the swallowing mechanism and the vocal cord are located close to the jugular bulb. Occasionally, these tumors can push or invade these nerves and create dysfunctional swallowing and hoarseness of the voice. Not infrequently because of the relative slow growth, the swallowing mechanism and vocal cord from the opposite side overcompensate so that the patient may not even notice a swallowing or vocal problem. It is not currently possible by imaging (X-rays, etc.) to determine whether the tumor has merely pushed the nerves aside or frankly invaded them. As these tumors grow, they can also invade the facial nerve, leading to a facial paralysis, or the hypoglossal nerve, leading to paralysis of half of the tongue. Additional growth can lead to tumor compression of the brain and/or brainstem.
Complications of Carotid Body Tumors
If a tumor has invaded the carotid body, blood flow to the head can be cut off, thus causing damage to the brain.