Article ID: cr.2019-0094
Ganglioneuroma is a rare tumor. Such tumor arising from cranial nerve is further rare. So far our knowledge, in the literature there is no report of ganglioneuroma involving glossopharyngeal nerve. Here, we report a case of very small glossopharyngeal nerve ganglioneuroma and the patient also had longstanding glossopharyngeal neuralgia (GPN).
Case Report: A 40-year-old male diagnosed case of left GPN for last 7 years presented with gradual unresponsiveness of drug for last 5 years. Due to severity of pain sometime, he wished to do suicide. Magnetic resonance imaging (MRI) of head revealed only suspected loop of vessel in root entry zones of 9th and 10 cranial nerves on left side. The patient underwent explorative posterior fossa craniotomy. Careful dissection of arachnoid over 9th cranial nerve near jugular foramen (JF) revealed thick and red color nerve with nodularity (tumor like). Dissection of arachnoid at nerve root entry zones of 9th and 10th nerves also revealed an aberrant loop of posterior inferior cerebellar artery (PICA). The 9th nerve was transected and suspected “tumorous portion” of nerve was sent for histopathological examination. The PICA loop was dissected away from root entry zones by placing muscle and surgical between 10th nerve roots and PICA loop. He made an uneventful recovery. Histopathological examination revealed ganglioneuroma. Immunohistochemistry confirmed ganglioneuroma. Six months after the operation, he was free of symptoms. In this case, probably previously existing GPN was worsen by the growth of ganglioneuroma and surgical treatment brought gratifying result.
Ganglioneuroma is a neural crest origin tumor commonly occurs in mediastinum, adrenal glands, and peripheral nervous system but very rarely it occur in cranial cavity.1–3) Very few cases of intracranial ganglioneuroma arising from the trigeminal nerve have been reported in the literature.2,3) Glossopharyngeal neuralgia (GPN) is a rare clinical condition characterized by intense lancinating pain in throat commonly triggered by swallowing4) but also by talking, chewing, yawning, and laughing. The pain is severe and paroxysmal; it originates in the throat, approximately in the tonsilar fossa. It may be localized in the ear or radiates from the throat to the ear, indicating the auricular branch of the 10th cranial nerve.5) Most GPN is assumed to be due to the compression of a cranial nerve by the vessels, commonly by posterior inferior cerebellar artery (PICA) or vertebral artery (VA). However, GPNs can also be caused by compression of a nerve by a mass lesion. There is several reports where tumors are associated GPN1,2,3,6) where ix nerve is compressed by extrinsic large size tumor in cerebello-pontine angle (CPA) but till today, there is no report of glossopharyngeal nerve ganglioneuroma or ganglioneuroma of ix nerve with pre-existing GPN. Here, we report a case of very small glossopharyngeal nerve ganglioneuroma near jugular foramen (JF) and the patient also had longstanding GPN.
A 40-year-male presented with recurrent sudden, severe lancinating, short lasting (15–20 seconds) pain in throat for last 11 years and he was a diagnosed as left GPN. The pain was precipitated by taking food (swallowing/chewing) or drink from left side of the throat and then to retro-mandibular region and ear. Sometimes, due to severity of pain, he wished to do suicide. There was history of series of pain event, that is, 30–40 times pain attacks within days to week. Then, it might remain silent for several weeks and again recur irrespective of taking drug. Initially, the pain responded well with tab. carbamazepine. Later, it became unresponsive to the carbamazepine especially for last 5 years. His neurological and other systemic examinations were normal. Past medical and family histories were unremarkable. Routine laboratory investigations including X-ray cervical spine (including head–neck junction) were also normal. Magnetic resonance imaging (MRI) of head 3D CISS (FIESTA) images revealed suspected loop of vessel in root entry zone of 9th and 10th cranial nerves on left side (Fig. 1). Left-sided glossopharyngeal nerve was thick and irregular in comparison to right side (Fig. 1C) (detected by reviewing after operation).
The patient underwent explorative retromastoid, retrosigmoid lateral suboccipital craniotomy in park bench position keeping left side up under general anesthesia. After opening the dura, lower CPA was exposed. Lower cranial nerves were exposed and identified after incision and dissection of arachnoid over it. There was some arachnoid thickening and scaring on 9th cranial nerve near upper compartment of JF. After careful dissection over 9th cranial nerve near JF, the nerve was found thick, red and nodular (tumor like). Further dissection of arachnoid at nerve root entry zone of 9th and 10th nerves revealed an aberrant loop of PICA (Figs. 2A and 2B) The 9th nerve was transected and suspected “tumorous portion” of nerve was sent for histopathological examination (Figs. 2C–2F). The PICA loop was dissected away from root entry zones (both 9th and 10th cranial nerves) by placing muscle-fascia and surgical between 10th nerve roots and PICA loop.
His symptoms resolved postoperatively but developed low-pitched voice with hoarseness without any swallowing problem that recovered completely within 10 weeks after operation. The computed tomography (CT) scan obtained on the 1st postoperative day showed nothing abnormal other than the post craniotomy state. He made an uneventful recovery and was discharged. Histopathological examination revealed ganglioneuroma (Fig. 3). Immunohistochemistry staining showed S 100, GFPA, NSE, NFP, and Chromogranin positive and Cytokeratin, Vimentin & CD31 negative, which confirmed ganglioneuroma. Six months after the operation, he was completely symptom-free.
In idiopathic GPN, the pain is similar to trigeminal neuralgia but it is localized to the ear (external), the base of the tongue, the palatine tonsil, or the area behind the mandibular angle.5) In 1889, Pope first reported the association between glossopharyngeal nerve and vascular compression of the 9th cranial nerve roots.5) He described a case with pain and loss of taste sensation from compression of the 9th cranial nerve by a dilated and thrombosed VA. Lillie and Craig5) in 1936 described an anomalous arterial loop as the cause of GPN. Although aberrant vascular compression is the most common etiology, multiple sclerosis, posterior fossa tumor, cyst, and trauma can also cause GPN. Several pathogenic mechanisms may produce GPN. So aberrant vascular compression, neoplasms in the CPA, extracranial lesions, and unknown etiology may cause GPN.6,7) GPN due to a CPA neoplasm (such as epidermoid) has been previously reported; however, it is very rare and usually occurs due to compression on glossopharyngeal nerve by a large cerebello-pontine tumor.2,6,8) Our case is the first case of GPN completely resolved after removal ganglioneuroma with glossopharyngeal neurectomy as well as micro-vascular decompression (MVD) to decompress the glossopharyngeal nerve roots with vagal nerve roots. Here, we think ganglioneuroma was just incidental development of tumor in the patient with pre-existing neuralgia and it might worsened the neuralgic sufferings of the patient.
Ganglioneuroma is a rare and benign tumor of the autonomic nerve fibers arising from neural crest sympathogonia, which are completely undifferentiated cells of the sympathetic nervous system.9) However, ganglioneuromas themselves are fully differentiated neuronal tumors that do not contain immature elements.10) Ganglioneuromas most frequently occur in the abdomen; however, these tumors can grow anywhere sympathetic nervous tissue is found. Other common locations include the adrenal gland, paraspinal retroperitoneum, posterior mediastinum, head, and neck.9)
Intracranial ganglioneuroma is very rare. Only few cases of ganglioneuroma involving 5th cranial nerve were reported.3) Ganglioneuroma involving other cranial nerves including glossopharyngeal nerve was not reported.
Commonly GPN is a clinical diagnosis but neuroimaging is used in identification of the underlying pathology, such as aberrant vascular compression, neoplasms, or demyelinating plaques. High-resolution MRI is very sensitive tool for detecting aberrant vascular compression.11) In this case, MRI could suspect that an aberrant vascular loop may compressing the nerve root but failed to identify the ganglioneuroma arising from 9th cranial nerve roots near JF as found per operatively. After operation when we reviewed the MRI images, we found that the nerve roots near JF were irregular and thick.
Despite new anti-epileptic drugs in the treatment of GPN, microsurgery is needed in the patients who show drug intolerance, refractoriness, or both.12–14) Several surgical treatments to medically intractable GPN based on the destruction of the glossopharyngeal and vagus nerve fibers12) are now rarely used. Now a days, MVD is an effective treatment and should be used as the first treatment in drug-resistant GPN with aberrant vascular compression.12,13) In addition to aberrant vascular compression, neoplasm-like conditions originating from nerve itself may cause hyperactive dysfunction syndromes by compression and irritation of its own nerve fibers and fascicles.6,8) In our case, causes of GPN were due to an aberrant vessel (i.e., PICA) compressing the glossopharyngeal nerve (confirmed intra-operatively) and ganglioneuroma originating from glossopharyngeal nerve roots near JF (found during operation and identified retrogradely on MRI) might have worsened the GPN instead of being the etiology of GPN.
In this case, glossopharyngeal ganglioneuroma developed in pre-existing GPN patient, which might further increase the woe of the neuralgia and surgical treatment brought gratifying result.
There are no conflicts of interest and nothing to disclose.
