Inflammatory pseudotumor of the trigeminal nerve: a neoplastic mimic you do not want to miss

Clivus Inflammatory Pseudotumor Associated with Immunoglobulin G4-Related Disease

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease is a more recently recognized syndrome. It is characterized by increasing IgG4-positive plasma cells and lymphocyte infiltration. Reports of intracranial pseudotumors associated with IgG4-related disease are very rare. We report a rare case of clivus pseudotumor associated with IgG4-related disease mimicking meningioma.

CASE DESCRIPTION

A 50-year-old man presented with abducens paralysis of the right eye. Brain magnetic resonance imaging revealed a uniformly enhanced mass located in the right upper clivus area, and meningioma was highly suspected. The tumor was totally resected via a retrosigmoid approach craniotomy, which achieved sufficient decompression of the right abducens nerve. Postoperative pathology revealed IgG4-related disease with IgG4 strongly positive on immunohistochemical staining. The patient had no history of autoimmune disease. Postoperative laboratory data revealed no elevation of either IgG (6.94 g/L) or IgG4 (0.131 g/L). Follow-up contrast MRI showed the lesion had disappeared.

CONCLUSIONS

Although several cases of intrasellar hypophysitis have been reported, reports of intracranial pseudotumors associated with IgG4-related disease are rare. Special attention is required when the differential diagnosis includes meningioma. Preoperative diagnosis is very important because inflammatory pseudotumors associated with IgG4-related disease could be treated with steroid therapy, avoiding surgery.

Inflammatory Pseudotumor of the Infraorbital Nerve: A Rare Diagnosis to Be Aware of

Inflammatory pseudotumor (IPT) is a rare benign mass-forming disease that can arise anywhere throughout the body, mimicking a wide spectrum of other conditions. Its diagnosis can be challenging, especially when it involves uncommon sites. The authors report a patient of an atypical localization of IPT, occurred as an enlarging bulk in the infraorbital nerve channel in a patient who presented with facial numbness. Clinical and radiological aspects similar to schwannoma led to misdiagnosis and over-treatment. The differential diagnosis of an infraorbital mass should include IPT and the least invasive treatment should be preferred, as steroid therapy being the first-line treatment for IPT.

Sinonasal and ventral skull base inflammatory pseudotumor: a systematic review

OBJECTIVES/HYPOTHESIS

Inflammatory pseudotumor is a benign idiopathic inflammatory process often misdiagnosed as an infection or neoplasm. This review analyzes all reported cases of sinonasal and ventral skull base inflammatory pseudotumor to date, and provides a framework for evaluation and management of this uncommon condition.

DATA SOURCES

MEDLINE/PubMed database.

REVIEW METHODS

A search for articles related to sinonasal and ventral skull base inflammatory pseudotumor, along with bibliographies of those articles, was performed. Demographics, presentation, radiographic findings, treatment, follow-up, and outcome were analyzed.

RESULTS

Thirty-three articles were reviewed, including a total of 87 patients. The most common presenting symptom was vision change (58.6%). Sinonasal and ventral skull base inflammatory pseudotumor was found in the cavernous sinus in 46.0% of cases. The lesion appeared isointense (66.7% of cases) and homogeneously enhancing on T1-weighted magnetic resonance imaging (MRI), whereas it appeared hypointense on T2-weighted MRI in 90.7% of cases. Inflammatory pseudotumor appeared hyperdense on computed tomography in 78.9% of cases. Histopathological analysis of biopsied specimens revealed presence of inflammatory cells (94.4%) and fibrosis (80.3%). Corticosteroids alone were the most common treatment modality (55.2%), resulting in disease-free patients in 22.9% of cases over a median follow-up period of 17.6 months. Surgical management alone was uncommon (8.0%), but showed high success rate (57.1%).

CONCLUSION

This review is the most comprehensive analysis of sinonasal and ventral skull base inflammatory pseudotumor to date. Radiologic findings and histopathological analysis are essential for diagnosis. Corticosteroids are the most common treatment modality. Surgery, although uncommon, appears to be an efficacious treatment modality.

Inflammatory myofibroblastic tumour of the skull base

Inflammatory myofibroblastic tumors (IMTs) are rare benign clinical and pathological entities. IMTs have been described in the lungs, abdomen, retroperitoneum, and extremities but rarely in the head and neck region. A 38-year-old man presented with headache, right exophthalmia, and right 6th nerve palsy. A CT scan revealed enlargement of the right cavernous sinus and osteolytic lesions of the right sphenoid and clivus. MR imaging showed a large tumor of the skull base which was invading the sella turcica, right cavernous sinus, and sphenoidal sinus. A biopsy was performed and revealed an IMT. Corticosteroids were given for 3 months but were inefficient. In the framework of our pluridisciplinary consultation, fractionated conformal radiotherapy (FRT) was indicated at a low dose; 20 Gy in 10 fractions of 2 Gy over 12 days were delivered. Clinical response was complete 3 months after FRT. Radiological response was subtotal 6 months after FRT. Two years later, the patient is well.

Immunoglobulin G4-related intracranial inflammatory pseudotumours along both the oculomotor nerves

We report the first documented case of IgG4-related inflammatory pseudotumours (IPTs) along the bilateral oculomotor nerves. A man in his 60s complained of decreased vision. He exhibited bilateral optic nerve atrophy without any extraocular movement deficits. MRI revealed enhanced masses that reached from the bilateral cavernous sinus to within the bilateral orbits. The tumours extended along the lines of the bilateral oculomotor nerves. The patient's serum level of IgG4 was high, 147 mg/dl. A biopsy specimen showed inflammatory cell-rich lesions against a collagenous stroma. Immunostaining revealed infiltration of CD138-positive plasma cells, which were mainly IgG and IgG4 positive. The IgG4/IgG ratio was greater than 0.4. These factors led us to a diagnosis of IgG4-related IPTs. Oral administration of prednisolone (30 mg/day) was started 3 months after the operation and continued for 6 months with gradual tapering. The tumour was significantly reduced by prednisolone.

Recurrent inflammatory pseudotumor of the jaw with perineural intracranial invasion demonstrating sustained response to Rituximab

Corticosteroids are the mainstay of treatment of inflammatory pseudotumor (IPT) of the head and neck; however, involvement of the skull base and mandible can be unresponsive to steroids and require surgical resection. IPT is known to usually contain a CD20+ lymphocyte subgroup. Rituximab, a chimeric anti-CD20 antibody, has been successfully utilized in the treatment of other CD20+ diseases, including the similar idiopathic orbital inflammatory disease. This is the first report to describe successful treatment with Rituximab of a recurrent IPT of the mandible with trigeminal spread and leptomeningeal involvement with clinical and radiologic evidence demonstrating a sustained response to therapy.

Bilateral inflammatory pseudotumour of the trigeminal nerve: a diagnostic challenge

Inflammatory pseudotumour (IPT) is an uncommon disease with undefined pathogenesis. It is often characterized by local aggressiveness with compressive and displacing effects on surrounding structures. It may appear in different regions of the body, rarely involving perineural structures unilaterally. We present a case of a bilateral IPT around trigeminal branches in a patient with a long-term history of periorbital swelling and proptosis.

Lung cancer presenting with trigeminal neuropathy

The purpose of this case report is to describe MR imaging and CT findings of a patient in whom the first clinical and neuroradiological manifestation of a metastatic lung adenocarcinoma was unilateral trigeminal neuropathy caused by a presumed metastasis involving cisternal and Meckel's cave segments of ipsilateral trigeminal nerve. MR imaging and CT scan differential diagnosis of expansive lesions of the intracranial trigeminal nerve must include metastases. Physicians and neuroradiologists must be aware of metastases as an uncommon cause of trigeminal neuropathy, even as the presenting condition of cancer.

Inflammatory pseudotumor of nerve: clinicopathological characteristics and a potential therapy

We sought to determine the clinical, electrophysiological, neuroimaging, and pathological features of inflammatory pseudotumor of nerve. Five patients were identified. All cases presented with a gradually progressive mononeuropathy with symptoms of weakness, sensory loss, and prominent neuropathic pain. The median duration of symptoms was 7 months (range 3-36 months). Electrophysiological results were in keeping with chronic axonal mononeuropathies with variable findings of active denervation and reinnervation. MRI demonstrated irregular, large masses involving and surrounding nerve with heterogenous signal characteristics on T1- and T2-weighted and post-contrast sequences. Histopathological features of the nerve slightly varied but shared commonalities including chronic inflammatory infiltrates, increased collagen, and increased numbers of microvessels. Axonal degeneration and decreased density of myelinated fibers were also noted. Three patients were treated with weekly courses of intravenous steroids for 3 months. All reported improvement in pain and weakness. Inflammatory pseudotumor of nerve is not a neoplasm and has reactive features of inflammation, increased vascularity, and marked fibrosis. It presents as a progressive axonal mononeuropathy with weakness, sensory loss, and pain that may be episodic. The primary pathophysiology is unknown but the inflammation and response to treatment suggests that there may be an immune component.

IgG4-related inflammatory pseudotumor of the trigeminal nerve: another component of IgG4-related sclerosing disease?

IgG4-related IPTs have been reported in various sites and may form part of the spectrum of systemic IgG4-related sclerosing disease. Some pseudotumors are clinically and radiologically indistinguishable from malignant tumors. We present the first case of an IgG4-related IPT of the trigeminal nerve diagnosed histopathologically without involvement of any of the common sites. The trigeminal nerve pseudotumor may represent a component of IgG4-related sclerosing disease.