Inflammatory Pseudotumor of the Skull Base

Imaging features, therapies, and outcomes of fibrosing inflammatory pseudotumor of the nasopharynx: A systematic review

BACKGROUND AND PURPOSE

Fibrosing inflammatory pseudotumor (FIP) of the nasopharynx is a rare nonneoplastic inflammatory lesion that is frequently mistaken for malignancy or infection. It is often misdiagnosed by radiologists as nasopharyngeal carcinoma or lymphoma, resulting in multiple biopsies and delays in diagnosis. The purpose is to understand trends in clinical presentation, imaging findings, treatment modalities, and patient outcomes of nasopharyngeal FIP.

METHODS

MEDLINE and EMBASE databases were queried for articles related to FIP of the nasopharynx. Articles that described cases of FIP involving the nasopharynx were selected. Studies that described inflammatory pseudotumor of the nasopharynx associated with known distinct pathologic entities were excluded.

RESULTS

A total of 19 articles describing 37 patients were included. MRI findings were reported in 32 patients. All cases demonstrated avid gadolinium enhancement. T2-weighted imaging characteristics were described or displayed for 21 patients: 95% demonstrated hypointensity compared to surrounding mucosa. Fluorodeoxyglucose (FDG) PET/CT findings were reported for 6 patients, all demonstrating mild FDG avidity.

CONCLUSIONS

Nasopharyngeal FIP is a histological diagnosis of exclusion that presents with facial pain and, often, cranial neuropathies. Relatively low T2-weighted MRI signal should inform the interpreting neuroradiologist to include FIP as a differential consideration for both the ordering provider and pathologist. Corticosteroid therapy is the most frequently employed therapy and results in partial or complete response in most patients. Radiation therapy and anti-inflammatory medications have also been reported to have potential therapeutic roles.

Treatment and Prognosis of Inflammatory Pseudotumor of the Skull Base

Background Inflammatory pseudotumor (IPT) of the skull base is a rare, locally destructive lesion managed with a variety of treatments. We explore the impact of treatment on outcome and assess the prognosis of IPT.

Methods This is a retrospective review of IPT of the skull base at a tertiary academic medical center. The primary outcome was radiographic progression after treatment. Outcome versus tumor location was also examined and a prognostic model was developed using a logistic regression.

Results The demographics of 21 patients with IPT are reported. Treatment consisted of corticosteroids (in 80.1% of patients), disease modifying antirheumatic drugs (DMARDs; 33.3%), surgical resection (28.6%), radiation (23.8%), antibiotics (14.3%), chemotherapy (rituximab; 9.5%), and antivirals (4.8%). At 50.7 months, 50.8% had radiographic progression. Local therapy trended toward having a better response than systemic therapy (p = 0.60). IPT of the orbit required 2.4 treatment modalities, compared with 2.0 for pharyngeal IPT, and 1.3 for posterior skull base masses (p = 0.14). A total of 75% orbital IPT underwent radiographic progression, compared with 71% of pharyngeal IPT and 50% of posterior skull base masses (p = 0.62). Sixteen patients were used to create the logistic model of radiographic progression. The Cox–Snell R 2 was 0.71 (p = 0.03). No individual variables were statistically significant.

Conclusion To our knowledge, this is among the largest sample of cases describing the presentation, treatment, and prognosis of IPT of the skull base. Our data suggest that there may be an improved response with local therapy over systemic therapy and better prognosis among posterolateral skull base masses.

Clinical significance of IgG4 in sinonasal and skull base inflammatory pseudotumor

INTRODUCTION

Inflammatory pseudotumor (IPT) in the sinonasal cavity and skull base region is benign non-neoplastic inflammatory process. However, IPT can mimic malignant tumor or infectious disease and there are difficulties in confirmation of diagnosis. The aim of study is to evaluate the clinical significance of immunoglobulin G4 (IgG4) in IPT in terms of steroid response and differential diagnosis with other skull base infiltrative lesions.

METHODS

Medical records were reviewed retrospectively from 1998 to 2016. Subjects diagnosed with IPT by surgical biopsy were enrolled. IgG4 positivity was defined as IgG4/IgG ratio > 0.4. Additionally, IgG4/IgG ratio was calculated in eight skull base osteomyelitis (SBO) patients.

RESULTS

Twenty-six IPT patients were included and the average age was 52.3 years, and 57.7% were male and 42.3% were female. Most lesions were involved in the sinuses (88.5%) and the incidence of extension beyond the sinuses itself was as follows: the cheek/hard palate/parapharynx (15.4%), orbit (61.5%), skull base (57.7%), and dura or brain (23.1%). All IPT cases revealed IgG4 + plasma cells and IgG4/IgG ratio over 0.4 was detected in 42.3% (11/26) of cases. In case of SBO, no patients had IgG4/IgG ratio exceed 0.4. Main treatment modality was systemic steroids (61.5%) and other modalities were used: surgery (3.8%), immunosuppressant (7.7%), radiotherapy (30.8%), or a combination of these modalities (15.4%). Steroid responses were not significantly different, but IgG4-positive group tended to have better response to steroid therapy.

CONCLUSIONS

IgG4-positive and IgG4-negative IPT patients revealed no differences in involvement sites, clinical course, and steroid responses. However, IgG4/IgG ratio and IgG4 + plasma cell count can provide a diagnostic clue for infiltrative skull base lesions such as IPT and a differential diagnosis of SBO.

Recurrent inflammatory myofibroblastic tumour of the lung: FDG PET/CT scan findings

Inflammatory myofibroblastic tumour (IMT) is a rare neoplasm, occurring most often in children and young adults. IMTs have intermediate biological behaviour with the chance of local invasion, recurrence and even distant metastasis. Wide range of clinical presentations makes the precise diagnosis of IMT more challenging. The best method for definitive diagnosis is tissue biopsy and newer imaging modalities including fleurodeoxyglucose (FDG) positron emission tomography (PET)/CT are useful tools in detection of disease recurrence or distant metastasis. Complete surgical resection is the best-known treatment for this tumour. Here we are presenting an IMT case in a 12-year-old girl in which her recurrent pulmonary IMT was diagnosed based on FDG PET/CT findings and referred for further salvage treatment. Overall imaging modalities are not specific, but PET/CT scan can be useful tool for evaluation of IMT regarding initial staging and restaging to assess treatment response and recurrence.

Extrasinonasal infiltrative process associated with a sinonasal fungus ball: does it mean invasive fungal sinusitis?

PURPOSE

Invasive fungal sinusitis (IFS) has rarely been reported to develop from non-IFS. The purpose of this study was to disclose the nature of the extrasinonasal infiltrative process in the presence of a sinonasal fungus ball (FB).

METHODS

We retrospectively reviewed the medical records, computed tomography, magnetic resonance images of 13 patients with sinonasal FB and the extrasinonasal infiltrative process. Based on histology and clinical course, we divided the extrasinonasal infiltrative process into IFS and the nonfungal inflammatory/infectious process (NFIP). The images were analyzed with particular attention to the presence of cervicofacial tissue infarction (CFTI).

RESULTS

Of the 13 patients, IFS was confirmed in only one, while the remaining 12 were diagnosed to have presumed NFIP. One patient with IFS died shortly after diagnosis. In contrast, all 12 patients with presumed NFIP, except one, survived during a mean follow-up of 17 months. FB was located in the maxillary sinus (n=4), sphenoid sinus (n=8), and both sinuses (n=1). Bone defect was found in five patients, of whom four had a defect in the sphenoid sinus. Various sites were involved in the extrasinonasal infiltrative process, including the orbit (n=10), intracranial cavity (n=9), and soft tissues of the face and neck (n=7). CFTI was recognized only in one patient with IFS.

CONCLUSION

In most cases, the extrasinonasal infiltrative process in the presence of sinonasal FB did not seem to be caused by IFS but probably by NFIP. In our study, there were more cases of invasive changes with the sphenoid than with the maxillary FB.

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.

Ophthalmic manifestations of IgG4-related disease: single-center experience and literature review

OBJECTIVES

IgG4-related disease (IgG4-RD) is an inflammatory disorder responsible for fibrosing, tumefactive lesions that can involve the lacrimal gland as well as the extraocular muscles, orbital soft tissues, sclera, and local nerves. We reviewed IgG4-related ophthalmic disease (IgG4-ROD), including the natural history, pathology, and treatment, based on our center's experience and that reported in the literature.

METHODS

We identified 27 patients with orbital manifestations from our IgG4-RD registry; six were excluded because no pathology was available for review. All 21 cases included had histopathologically confirmed diagnoses of IgG4-RD, 11 of which were of the orbital tissue. Other data were obtained by a retrospective medical records review. MEDLINE and PubMed literature searches in English were conducted to identify articles for a literature review on the topic.

RESULTS

Patients with IgG4-ROD were predominantly male (57%) and had an average age at symptom onset of 50 years (range: 21-79 years). The lacrimal gland was the most commonly involved structure (62%). Most patients (71%) had bilateral disease and extra-orbital involvement (71%); these patients also had elevated serum IgG4 concentrations compared to those with unilateral disease and no extra-orbital disease. Ten patients improved following rituximab treatment.

CONCLUSIONS

Ophthalmic involvement is a common manifestation of IgG4-RD and can affect nearly every orbital structure. Consideration of IgG4-RD and accurate diagnosis by biopsy have important implications for prognosis and treatment following the distinction of this condition from the Sjögren syndrome (SjS), granulomatosis with polyangiitis (GPA, formerly Wegener's), sarcoidosis, lymphoma, infection, and other disorders. Rituximab holds promise as an effective steroid-sparing agent or therapy for steroid-resistant cases.

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.

Imaging of inflammatory myofibroblastic cervical tumours: a case report

Among the family of mesenchymatous tumours, inflammatory myofibroblastic tumours (IMT) are an increasingly recognised and defined lesional group due to the great many studies and recent publications. The aetiopathogenicity is still not fully understood. It seems that an immune origin is involved in the pathological process. These masses result from the proliferation of fibroblast and lymphocyte cells associated with collagen wickerwork. Most often benign, they may affect any organ or supporting tissue. However, these lesions remain non-specific and are difficult to distinguish from malignant tumoral processes. Here resides the value of imaging: to make the diagnosis, guide the biopsy and thereby avoid early damaging surgery or an aggressive medical treatment. This is all the more valid since recent papers have shown that corticotherapy of short duration is currently the first intention treatment We here describe the case of a female patient presenting disseminated erythematous lupus who presented a cervical myofibroblastic tumour. The early diagnosis allowed for the initial medical care, which turned out to be effective without resorting to surgery.

Inflammatory pseudotumor of the skull base involving fissura petrooccipitalis: a rare case with challenging diagnosis

Inflammatory pseudotumor (IPT) is a benign entity that may present as a solid mass mimicking a malignant neoplasm. Histologically, they are composed of varying proportions of myofibroblastic spindle cells, lymphocytes, and plasma cells. Skull base IPT is rare and usually occurs in adults with no sex predilection. The skull base IPT typically presents with headache, and/or cranial nerve palsy. There is no consensus regarding treatment of skull base IPT due to its rarity. Surgical resection and corticosteroid therapy have generally been used. The preoperative diagnosis of skull base IPT is usually difficult due to its nonspecific clinical and radiologic features. We report a case of a 42-year-old woman with IPT originating from the skull base. To our knowledge, this is the first case of IPT invading fissura petrooccipitalis. When a mass in the skull base appears hypointense on T2-weighted imaging with aggressive growth and bony destruction, IPT should be considered in the differential diagnosis.

[Inflammatory myofibroblastic tumour of the tonsil: case report and literature review]

Inflammatory myofibroblastic tumour (inflammatory pseudotumor) is an idiopathic lesion, rare in the head and neck, of unknown aetiology. It is primarily a soft tissue, lung and orbital condition. In the world literature, only two cases with tonsillar disease have been found. We report a case of a 10-year-old girl admitted to our hospital with clinical complaints of pain in the neck region, cough with vomiting, dyspnoea and dyslexia. Clinical examination revealed halitosis and a neoformation dependent on the left tonsil. Bilateral tonsillectomy was performed.

Inflammatory pseudotumor (plasma cell granuloma) of the temporal bone

We report the case of a 41-year-old man who presented with progressive right-sided ear pressure, otalgia, hearing loss, tinnitus, and intermittent otorrhea. Computed tomography and magnetic resonance imaging detected a soft-tissue mass in the right mastoid with intracranial invasion and erosion through the tegmen tympani and mastoid cortex. Histopathologic examination was consistent with an inflammatory pseudotumor (plasma cell granuloma). These lesions rarely occur in the temporal bone. When they do, they are locally destructive and can erode bone and soft tissues. Aggressive surgery is recommended as a first-line treatment, with adjunctive steroid or radiotherapy reserved for residual or refractory disease. Our patient subsequently experienced multiple recurrences, and his treatment required all of these modalities. At the most recent follow-up, he was disease-free and doing well.