Fibrosing inflammatory pseudotumors of the central skull base

Diagnosis and Treatment of Inflammatory Pseudotumor with Lower Cranial Nerve Neuropathy by Endoscopic Endonasal Approach: A Systematic Review

Inflammatory pseudotumor (IPT) is a non-neoplastic condition of unknown etiology. IPT with lower cranial nerve (CN IX, X, XI, XII) neuropathies is extremely rare. In this study, we systematically reviewed all previously reported cases regarding the management of IPT with lower cranial nerve neuropathies. We searched the PubMed/MEDLINE database for reports related to IPT with lower cranial nerve neuropathies. A total of six papers with 10 cases met the inclusion criteria (mean age 51.6 years, 70% male). The mean follow-up period was 15.4 months (range: 1–60 months). The most frequent treatment was corticosteroids alone (60%), followed by surgery alone (20%), and multimodal treatment (20%). Corticosteroid therapy was associated with an excellent (100%) response rate at 6 months of follow-up, and half of the patients were in complete remission after 9 months. Both cases who received surgery had persistent neurological deficits. Immediate complete remission of neurological symptoms and resolution on imaging after decompression surgery via an endoscopic endonasal approach (EEA) with corticosteroids was demonstrated in our representative case. This review suggests that EEA is a preferred method for diagnosis and treatment, a promising approach associated with favorable outcomes, and a viable first-line treatment for selected cases, followed by multimodal therapy.

Fibrosing Inflammatory Pseudotumor Presenting as Cranial Neuropathy

We report two cases of biopsy-corroborated “fibrosing inflammatory pseudotumor” to illustrate that the entity, rarely described in the neurological literature, should be included in the differential diagnosis of either a cranial mononeuropathy or, certainly, in the case of progressive cranial neuropathies. A broad differential diagnosis arises in certain contexts. Early steroid treatment can be effective, and perhaps later-generation immune-modulating agents may confer further options, although there is no known definitive treatment.

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 pseudotumor of the temporal bone: a case series

Inflammatory pseudotumor is a non-neoplastic inflammatory process. Histologically these lesions appear as an inflammatory infiltrate with a fibrotic background. Clinical presentations vary from slow growth with minimal mass effect, to bony destruction that can mimic malignancy. Although they occur most commonly in the orbit, there are a growing number of case reports of tumors of the temporal bone and skull base. Inflammatory pseudotumors of the temporal bone are best treated by excision, with radiation and steroid therapy reserved for inoperable tumors. The clinical, histologic, and radiographic features of two patients with inflammatory pseudotumor of the temporal bone are presented.

Fibrosing inflammatory pseudotumor of the nasopharynx: MR features and histopathologic correlation

PURPOSE

To describe the magnetic resonance (MR) imaging features of six cases of pathologically proven fibrosing inflammatory pseudotumor involving the nasopharynx, and to compare the MR signal intensities of the lesions with histopathologic findings.

METHODS

We reviewed the MR finding of six patients with pathologically proved fibrosing inflammatory pseudotumor at the nasopharyngeal wall with respect to the following points: extent, margins, signal intensity and enhancement degree of the lesion; cervical lymphadenopathy and response to steroid therapy. MR findings were correlated with histopathologic findings.

RESULTS

All lesions showed ill-defined margins and looked less-likely contour bulging features. The signal intensity of the lesions was hypointense or slightly heterogeneous relative to brain cortex on both T1- and T2-weighted images, and enhancement was weakly homogeneous in all cases. There was no demonstrable cervical lymphadenopathy in all cases. After steroid therapy, the lesions showed decreased extent and weaker enhancement in three patients. Histopathologic findings showed high degree of polymorphous inflammatory cellular infiltration with underlying significant reactive fibrosis.

CONCLUSION

Fibrotic inflammatory pseudotumors involving nasopharynx are very rare, and can mimic malignancy. MR imaging showed ill-defined margins, hypointensity or slightly heterogenous signal intensity on T2-weighted image and weak enhancement. There was no significant cervical lymphadenopathy.

Inflammatory pseudotumor involving the skull base: response to steroid and radiation therapy

OBJECTIVE

To evaluate the response to steroid and radiation therapy in inflammatory pseudotumor (IPT) involving the skull base.

STUDY DESIGN AND SETTING

Eight patients with IPT of the skull base were evaluated. Six patients were diabetic. All patients underwent initial high-dose steroid therapy. Seven of 8 patients underwent subsequent low-dose steroid maintenance. Additional low-dose radiation therapy was performed in 6 patients. We reviewed the medical records and radiologic findings of the patients to evaluate their responses to the steroid and radiation therapy.

RESULTS

In all patients, the initial response to steroid therapy was fair. However, 7 patients showed symptom recurrence after cessation of steroid therapy. In 5 of 6 patients, low-dose radiation therapy resulted in recurrence. On follow-up MRI, none of the patients showed complete remission of the disease.

CONCLUSION

This study shows aggressive clinical behavior of IPT involving the skull base and its poor response to steroid therapy and low-dose radiation therapy. For improving control, more aggressive initial efforts including high-dose radiation therapy with or without concurrent steroid therapy might play a role.

EBM RATING

C-4.