Plexiform schwannoma is a rare benign tumor arising from the peripheral nerve sheath and characterized by a multinodular and plexiform growth pattern. This tumor usually arises sporadically. In rare cases, plexiform schwannomas have been associated with neurofibromatosis type 2. Plexiform schwannoma should be differentiated from plexiform neurofibroma, because the latter is pathognomonic tumor of neurofibromatosis type 1 and has a potential of malignant transformation. We report a case of multiple plexiform schwannomas associated with bilateral acoustic neuromas and meningioma.
Meningioma ; Neurilemmoma* ; Neurofibroma, Plexiform ; Neurofibromatoses* ; Neurofibromatosis 1 ; Neurofibromatosis 2* ; Neuroma, Acoustic ; Peripheral Nerves

We present two cases of plexiform schwannoma, a benign peripheral nerve sheath tumor, characterized by a plexiform growth pattern. Plexiform schwannoma must be distinguished from plexiform neurofibroma because of the propensity of the latter for malignant degeneration. Although plexiform schwannoma usually arises sporadically, it can be rarely associated with neurofibromatosis type 2. We report two cases of plexiform schwannoma. One was single sporadic lesion on the abdomen of a 28-year-old woman. The other showed multiple plexiform schwannomas associated with bilateral acoustic neuromas.
Abdomen ; Adult ; Female ; Humans ; Neurilemmoma* ; Neurofibroma, Plexiform ; Neurofibromatosis 2 ; Neuroma, Acoustic ; Peripheral Nerves

About 10% of all intracranial tumors occur at the cerebellopontine angle(CPA). While the most common of these, accounting for about 75% of the total, are acoustic neurinomas, these-with widly varying histology-also comprise a significant portion. One of these is trigeminal neurinoma, which account for about 2-10% of all CPA tumors ; a cystic lesion is even rarer. The authors report a case of large cystic trigeminal neurinoma at the cerebellopontine angle and review of the pertinent literature.
Cerebellopontine Angle* ; Neurilemmoma* ; Neuroma, Acoustic ; Trigeminal Nerve

Neurofibromatosis 1(NF-1, Von Recklinghausen disease) and Neurofibromatosis 2(NF-2, bilateral acoustic neurinoma) have been established as distinct disorders by the National Institutes of Health(NIH) Consensus Development Conference in 1988. We recently have encountered a patient of NF-2 who develop multiple intracranial and spinal tumors 12 years after the surgical treatment of Schwannoma of lumbar nerve roots. The tumors were right acoustic neurinoma, left cerebellopontine angle(CPA) meningioma, multiple intracranial meningiomas, intraorbital glioma, multiple ependymomas of the brain stem and cervical spinal cord, and meningiomas of cervical nerve roots. We present this case with a review of reported cases of neurofibromatosis.
Academies and Institutes ; Acoustics ; Brain Stem ; Ependymoma ; Glioma ; Humans ; Meningioma ; Neurilemmoma ; Neurofibromatoses* ; Neurofibromatosis 2* ; Neuroma, Acoustic ; Spinal Cord

Plexiform schwannoma is a rare benign neoplasm of the neural sheath characterized by a multinodular plexiform growth pattern. The tumor usually occurs as an isolated finding, although rare cases have been reported in association with neurofibromatosis type 2 (NF2). A 25-year-old man was admitted for foot drop. He had an asymptomatic skin-colored nodule on his neck that had been present for 10 years. His medical history included local excision of a plexiform schwannoma on his left leg in our dermatology clinic 6 years prior. A histopathological examination of the skin-colored nodule also showed the typical microscopic features of a plexiform schwannoma, including the characteristic Antoni type A areas showing frequent nuclear palisading and Verocay bodies. Magnetic resonance imaging revealed a meningioma and a vestibular schwannoma in the cranium and multiple neurofibromas on the spinal cord. Herein we report a rare case of cutaneous plexiform schwannomas in a patient with NF2.
Adult ; Dermatology ; Foot ; Humans ; Leg ; Magnetic Resonance Imaging ; Meningioma ; Neck ; Neurilemmoma ; Neurofibromatoses ; Neurofibromatosis 2 ; Neuroma, Acoustic ; Skull ; Spinal Cord

Plexiform schwannoma is a rare variant of benign schwannoma characterized by a multinodular and plexiform growth pattern. Schwannomatosis is a recently recognized disorder, defined as multiple, pathologically-proven schwannoma without vestibular tumors, diagnostic of neurofibromatosis 2. Although plexiform schwannoma is usually solitary, multiple plexiform schwannomas do also occur as an isolated finding or in association with neurofibromatosis 2. We describe a 7-year-old girl who had multiple cutaneous plexiform schwannomas and neurologic deficits such as sensorineural hearing loss and amblyopia on her left side. Brain magnetic resonance imaging and ophthalmologic examination was negative for vestibular schwannoma and eye stigmata of neurofibromatosis 2. However, as there is a possibility that the patient may eventually develop additional cranial tumors such as meningiomas or vestibular schwannomas, we therefore recommend that she is periodically screened.
Amblyopia ; Brain ; Child ; Christianity ; Female ; Hearing Loss, Sensorineural ; Humans ; Magnetic Resonance Imaging ; Meningioma ; Neurilemmoma* ; Neurofibromatosis 2 ; Neurologic Manifestations* ; Neuroma, Acoustic

Schwannomas arising from the cranial nerves of the jugular foramen are rare, only 50 cases including 15 glossopharyngeal schwannomas have been reported. They may be confused with the far more common acoustic schwannoma because of the presenting symptom of hearing loss. With the symptoms and signs of the lower cranial nerve involvement, the characteristic radiographic findings of enlarged jugular foramen and normal internal acoustic meatus can make the diagnosis. The authors review the literature and present a unique case of glossopharyngeal schwannoma which had intra-and extracranial growth with intrapetrosal extension.
Acoustics ; Cranial Nerves ; Diagnosis ; Hearing Loss ; Neurilemmoma* ; Neuroma, Acoustic

Hearing loss in the contralateral functioning ear is a rare and distressing complication after vetibular schwannoma removal. Various possible mechanisms have been proposed, however, the etiology of hearing loss is not clear. Fortunately, this is an extremely rare occurrence, sporadic case reports have appeared in the literatures. We report two cases of acute contralateral hearing loss after vestibular schwannoma removal and discuss the possible mechanisms of the phenomenon. Although permanent deafness may result, in our cases, the hearing loss was temporary, returning to near preoperative level within one month. The etiology of hearing loss in one case is thought to be cerebrospinal fluid leakage. However, in the other case, the cause of hearing loss is not clear. A better understanding of these events may lead to preventive measures to avoid contralateral hearing loss after vestibular schwannoma removal.
Cerebrospinal Fluid ; Deafness ; Ear* ; Hearing Loss* ; Hearing* ; Neurilemmoma ; Neuroma, Acoustic*

Acoustic neurinoma are the most frequent tumors in the region of the cerebellopontine angle. They usually present with a gradual onset of symptoms and slow progression. Development of spontaneous hemorrhage with sudden aggravation of symptoms is rare. The authors present a case of acoustic neurinoma associated with a spontaneous intratumoral hemorrhage. Sudden aggravation of symptoms was noticed. The cranial computed tomography revealed multiple blood-fluid levels within the cysts of the tumor which was located in the region of the right cerebellopontine angle. Operation was performed, which confirmed recent hemorrhage within the tumor. Pathological study revealed a typical neurilemmoma associated with hemorrhage, vascular proliferation and macrophages which phagocytosed hemosiderin pigments. The rare sudden aggravation of symptoms in cases of acoustic neurinoma may suggest hemorrhage.
Acoustics* ; Cerebellopontine Angle ; Hemorrhage* ; Hemosiderin ; Macrophages ; Neurilemmoma ; Neuroma, Acoustic*

OBJECTIVES: Facial nerve schwannomas may be misdiagnosed as vestibular schwannomas (VSs) if the tumor is confined to the internal auditory canal (IAC) without involvement the geniculated ganglion or labyrinthine segment of facial nerve. Because facial nerve schwannomas may be misdiagnosed as VSs, we investigated the differences between the two. METHODS: The study included 187 patients with a preoperative diagnosis of VS. Of these, six were diagnosed with facial nerve schwannomas during surgery. We reviewed the preoperative evaluations and surgical findings of facial nerve schwannomas mimicking VSs. RESULTS: No useful preoperative predictors are available for facial nerve schwannomas mimicking VSs. Facial nerve schwannomas are usually confined to the IAC. After opening the dura of the IAC, a facial nerve schwannoma can be diagnosed after identifying a normal-appearing nerve located lateral to the tumor. When this was the case, we performed facial nerve preservation surgery or decompression. CONCLUSION: Facial nerve schwannomas can be differentiated from VSs by identifying specific findings during surgery.
Decompression ; Diagnosis ; Facial Nerve* ; Ganglion Cysts ; Humans ; Neurilemmoma* ; Neuroma, Acoustic*