Localized hypertrophic neuropathy involving the inferior alveolar nerve

Clinical Features, Natural History, and Outcomes of Intraneural Perineuriomas: A Systematic Review of the Literature

BACKGROUND

Intraneural perineurioma is a rare peripheral nerve sheath tumor characterized by localized proliferation of perineurial cells. The literature consists predominantly of case reports and institutional series, with inconsistent and confusing nomenclature. We present a pooled analysis of all reported cases of intraneural perineurioma in the literature.

METHODS

A systematic search of PubMed, MEDLINE, Embase, and Scopus was performed according to PRISMA guidelines to identify all reported cases of intraneural perineurioma in the literature. Individual cases were pooled and analyzed for demographics, clinical features, and outcomes.

RESULTS

A total of 172 cases were identified across 72 studies, of which 149 were found in major peripheral nerves and their branches. Median age of patients at diagnosis and onset of symptoms was 18 years (interquartile range [IQR], 12-34 years) years and 13.5 years (IQR, 8-26 years), respectively, with 54.4% (81/149) being female. The most common sites were the sciatic nerve or its branches (41.9%), median nerve (13.5%), radial nerve (12.2%), and brachial plexus (12.2%). Most patients were managed conservatively (52.9%; 72/136). Among those managed conservatively with available follow-up (n = 31), median follow-up was 11 months, and most (67.7%, n = 21) reported no change in neurologic status, although worsening was noted in 29.0% (9/31). Among surgically managed cases (n = 64), the most common intervention was resection with or without repair (62.5%; 40/64), neurolysis (25%; 16/64), or tendon transfers without resection (12.5%; 8/64). No lesion recurred after surgical resection.

CONCLUSIONS

Intraneural perineurioma represents a benign focal lesion presenting with weakness and atrophy affecting adolescents and young adults. Most cases are managed nonoperatively and surgical treatment strategies are varied.

Hypertrophic Interstitial Neuropathy of the Trigeminal Nerve: Case Report and Literature Review

BACKGROUND AND IMPORTANCE

Hypertrophic interstitial neuropathy (HIN) is an uncommon, non-neoplastic lesion typically affecting peripheral nerves. Cranial nerve (CN) involvement is exceedingly rare. We present a case of isolated trigeminal nerve HIN manifesting with V3 distribution neuralgia.

CLINICAL PRESENTATION

A 50-yr-old male presented with left sided trigeminal neuralgia refractory to medical management. The patient underwent retromastoid craniectomy for possible microvascular decompression. Intra-operatively, the trigeminal nerve appeared to be focally enlarged with a sausage-like configuration. We selectively resected 1 fascicle which was predominantly involved. Histopathological examination revealed onion bulb formations composed of Schwann cells around centrally placed axons. A diagnosis of HIN was made. Postoperatively, the patient experienced complete resolution of symptoms.

CONCLUSION

This is the third case of isolated trigeminal nerve HIN in the literature. We performed a selective resection in a patient presenting with trigeminal neuralgia, resulting in complete resolution of symptoms. It is reported here with intraoperative microscope images, along with a review and analysis of this topic as it related to CN.

Radiographic Enlargement of Mandibular Canal as an Extranodal Primary Non-Hodgkin's Lymphoma Early Sign in an Asymptomatic Patient

Non-Hodgkin's lymphoma (NHL) is a lymphoproliferative disorder, from a subgroup of heterogeneous hematologic malignancies; the term “extranodal” refers to malignant involvement of tissues other than lymph nodes, tonsils, spleen, pharyngeal lymphatic ring, or thymus. Only 0.6% of all NHL are at mandible alone, and it may involve the inferior alveolar canal. We describe a case of bilateral enlargement of the mandibular canal without symptomatology, which was shown in a panoramic radiograph and cone beam computed tomography in a rehabilitation routine exam, as an early sign of primary extranodal NHL.

Isolated Hypertrophic Neuropathy of the Oculomotor Nerve

BACKGROUND

Hypertrophic neuropathy is a rare entity commonly associated with peripheral nerve, characterized by onion bulb formations. Its cranial nerve involvement is very rare; only 7 cases have been found in the literature.

CASE DESCRIPTION

A 32-year-old white man with a 5-year history of intermittent right retro-orbital headache and mild right ptosis presented to the Neurosurgery Clinic. A magnetic resonance imaging of his brain demonstrated an enhancing lesion associated with the right third nerve. He underwent biopsy of the lesion, and its pathology report confirmed the diagnosis of hypertrophic neuropathy. Within 4 months, his third nerve palsy had completely resolved and was functioning fully.

CONCLUSIONS

Here, we report a first case of isolated hypertrophic neuropathy involving the oculomotor nerve.

Demyelinating hypertrophic inferior alveolar nerve mimicking a nerve tumor

We herein report a patient with demyelinating inferior alveolar nerve hypertrophy, which was initially suspected to have a nerve tumor. A 39-year-old woman with childhood-onset polyneuropathy presented with tooth pain and visited a dental clinic. An X-ray examination of the mandible revealed enlargement of the mandibular canal, and a nerve tumor was suspected. CT scan and MRI showed hypertrophy of the inferior alveolar nerve along its entire length. We diagnosed the patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), which was supported by the spontaneous recovery reported in her childhood, the results from a nerve conduction study and MRI data. CIDP should be considered in the differential diagnosis of mandibular canal enlargement.

Pseudoneoplasms of the Nervous System

Context.—Pseudoneoplasms of the nervous system vary greatly in nature. Ranging from inflammatory to autoimmune, infectious, malformative, reactive, degenerative, and radiation induced, they all mimic true tumors. Thus, they have the potential to mislead clinicians, radiologists, and pathologists alike. Their clinical and/or neuroimaging and histologic features are readily misinterpreted as tumor. Knowledge of the pitfalls is essential to avoid mismanagement, specifically overtreatment. In such instances, pathologists must take the entire clinical picture into consideration, acquainting themselves with presenting symptoms, physical findings, and neuroimaging.

Objective.—To present 10 examples of pseudoneoplasms of the nervous system, analyze the basis for their mimicry, and discuss their differential diagnosis.

Data Sources.—Review of the pertinent literature related to pseudoneoplasms of the nervous system and review of the consultation files of one of the authors (B.W.S.).

Conclusions.—The identification of tumor mimics may be difficult under the best of circumstances, and maintaining a broad differential diagnosis as well as application of a variety of immunocytochemical and occasionally ultrastructural and/or molecular genetic methods is essential to arrive at a correct diagnosis.

Widening of the inferior alveolar canal: a case report with atypical lymphocytic infiltration of the nerve

Widening of the inferior alveolar (mandibular) canal is a rare radiological finding. It is most often associated with neurofibromatosis. Rarely, a malignant process such as lymphoma may cause ill-defined enlargement of the mandibular canal. We present a unique case of a 33-year-old male who gradually developed sensory loss of his left lower lip and cheek and a well-defined tube-like widening of his left mandibular canal. The histopathological findings of the lesion were unusual in that they indicated atypical lymphocytic infiltration of the nerve tissue. The differential diagnoses regarding the clinical, radiological, and histopathological findings are discussed.

Radial nerve palsy owing to localized hypertrophic neuropathy (intraneural perineurioma) in early childhood

Localized hypertrophic neuropathy, also termed intraneural perineurioma, is a rare disorder of unknown etiology that produces a slowly progressive painless focal lesion of a peripheral nerve. It is characterized histologically by concentric whorls ("onion bulbs") of epithelial membrane antigen-reactive, S-100 protein-negative perineurial cells surrounding nerve fibers. We report a radial nerve palsy in a child aged 2 years in whom the diagnosis of localized hypertrophic neuropathy was made by biopsy. Resection of the affected nerve segment and sural nerve grafting produced no useful recovery after 3 years, probably because of the long duration of denervation. When this mononeuropathy presents in early childhood, uncertainty over the time of onset can lead to difficulty in distinguishing this potentially treatable lesion from congenital and other causes of nerve palsy.