Imaging of nasopharyngeal inflammatory pseudotumours: differential from nasopharyngeal carcinoma

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.

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.

To predict the radiosensitivity of nasopharyngeal carcinoma using intravoxel incoherent motion MRI at 3.0 T

PURPOSE

To investigate intravoxel incoherent motion (IVIM) MRI for evaluating the sensitivity of radiotherapy on nasopharyngeal carcinoma (NPC).

RESULTS

The reproducibility between intra-observer and inter-observer was relatively good. D (0.72×10^-3 mm²/s±0.14 vs. 0.54×10^-3 mm²/s±0.23; P < 0.001) and D* (157.92×10^-3 mm²/s±15.21 vs. 120.36×10^-3 mm²/s±10.22; P < 0.0001) were significantly higher in effective group than poor-effective group, whereas the difference of f (18.79%±2.51 vs. 16.47%±1.51) and ADC (1.21×10^-3 mm²/s±0.11 vs. 1.33×10^-3 mm²/s±0.23) could not reach statistical significant between the 2 groups (P > 0.05).

CONCLUSIONS

IVIM may be potentially useful in assessing the radiosensitivity of NPC. The higher D value combining with higher D* value might indicate the more radiosensitive of NPC, and increased D* might reflect increased blood vessel generation and parenchymal perfusion in NPC.

MATERIALS AND METHODS

Sixty consecutive patients (20 female, range, 27-83 years, mean age, 52 years) newly diagnosed NPC in the stage of T3 or T4 were enrolled. Forty-two of them were divided into effective group clinically after a standard radiotherapy according to the RECIST criteria. IVIM with 13 b-values (range, 0-800 s/mm²) and general MRI were performed at 3.0T MR scanner before and after radiotherapy. The parameters of IVIM including perfusion fraction (f), perfusion-related diffusion (D*), pure molecular diffusion (D) and apparent diffusion coefficient (ADC) were calculated. Two radiologists major in MRI diagnose analyzed all images independently and placed regions of interest (ROIs). Intra-class correlation coefficient (ICC) was used to evaluate intra-observer and inter-observer agreement. And Mann-Whitney test was used to assess the differences between the two groups.

Discrepant lesion size estimated on T1- and fat-suppressed T2-weighted MRI: diagnostic value for differentiation between inflammatory pseudotumor and carcinoma of the nasopharynx

PURPOSE

Nasopharyngeal inflammatory pseudotumor (NIPT) is hard to differentiate from infiltrating nasopharyngeal carcinoma (NPC) on conventional magnetic resonance imaging (MRI). The purpose of this study is to determine whether discrepant lesion sizes estimated on T1- and fat-suppressed T2-weighted images can help distinguish between NIPT and NPC.

METHODS

We retrospectively reviewed MRI data of histologically proven 14 NIPTs and 18 infiltrating NPCs. We measured the area of the lesion on contrast-enhanced T1-weighted, unenhanced T1-weighted, and fat-suppressed T2-weighted images by placing the largest possible polygonal region-of-interest within the lesion at the same level. Using lesion size measured on contrast-enhanced T1-weighted image as the reference, we calculated and compared area ratio of T1 (ART1) and area ratio of T2 (ART2) between NIPTs and NPCs. For validation, we also undertook a double-blinded study by two reviewers and assessed the diagnostic performance and interobserver agreement.

RESULTS

For NIPTs, ART2 (median, 0.48; range, 0.18-0.97) was statistically significantly less than ART1 (median, 1.01; range, 0.80-1.99), while these values were not significantly different for NPCs. The interobserver agreement in differentiating between NIPT and NPC was good, with a sensitivity of 93% and a specificity of 83%-94%.

CONCLUSION

In contrast to NPCs, NIPTs appear smaller on fat-suppressed T2-weighted images than on T1-weighted images. This discrepancy in the lesion size estimated on T1-weighted and fat-suppressed T2-weighted images may provide a simple and consistent way to differentiate between NIPTs and NPCs on conventional MRI.

Inflammatory Pseudotumors of the Skull Base: Meta-Analysis

OBJECTIVE

To describe the presentation, treatment, and outcome of inflammatory pseudotumors (IPs) of the skull base.

DATA SOURCES

English-language articles in PubMed, Web of Science, and EMBASE from earliest available through April 2014.

STUDY SELECTION

Articles were identified using a keyword search for "inflammatory pseudotumor," "inflammatory myofibroblastoma," or "plasma cell granuloma," including a keyword localizing to the skull base.

DATA EXTRACTION

One hundred papers with 157 cases met inclusion criteria. History, tumor site, initial and subsequent treatment, outcomes, and complications were extracted. Student t test, z test, and analysis of variance were used to analyze demographics, symptoms, sites involved, and outcomes. Odds ratios for site versus initial treatment were calculated.

DATA SYNTHESIS

At diagnosis, average patient age was 41 years. Approximately 70% of lesions primarily involved the anterior skull base, 29% the lateral skull base, and 1.2% the occiput. The most common initial treatments were steroids (44%), surgery (28%), and surgery with steroids (16%). Anterior lesions were 55.8 times more likely than lateral lesions to be treated initially with steroids (CI, 14.7-212). Seventy-six percent of patients had stable or resolved symptoms after a single course of treatment.

CONCLUSION

Diagnosis of skull base IP requires ruling out other aggressive pathologies, such as malignancy and infection, and maintaining a high index of suspicion. Surgery is favored for lesions that can be removed in toto with minimal morbidity, as well as steroids for those sites where anatomy limits complete resection, such as within the orbit, cavernous sinus, or brain. An option for larger lesions involving vital anatomy is debulking, followed by postoperative steroids.

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.

Intravoxel incoherent motion MRI: emerging applications for nasopharyngeal carcinoma at the primary site

Objectives

We compared pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) based on intravoxel incoherent motion (IVIM) theory in patients with nasopharyngeal carcinoma (NPC).

Methods

Sixty-five consecutive patients (48 men) with suspected NPC were examined using a 3.0-T MR system. Diffusion-weighted imaging (DWI) was performed with 13 b values (range, 0–800 s/mm²). We regarded the result of endoscopy and biopsy as the gold standard for detection. D, D* and f were compared between patients with primary NPC and enlarged adenoids.

Results

IVIM DWI was successful in 37 of 40 NPC and 23 of 25 enlarged adenoids cases. D (P = 0.001) and f (P < 0.0001) were significantly lower in patients with NPC than in patients with enlarged adenoids, whereas D* was significantly higher (P < 0.0001). However, the ADC was not significantly different between the two groups (P > 0.05). The area under the ROC curve (AUC) for D was 0.849 and was significantly larger than that for ADC (P < 0.05).

Conclusions

IVIM DWI is a feasible technique for investigating primary NPC. D was significantly decreased in primary NPC, and increased D* reflected increased blood vessel generation and parenchymal perfusion in primary NPC.

Key Points

• Intravoxel incoherent motion (IVIM) analysis permits separate quantification of diffusion and perfusion.

• IVIM DWI is a feasible technique for investigating primary NPC.

• IVIM suggests that primary NPC tissue voxels exhibit both perfusion and diffusion.

Computed tomography and magnetic resonance imaging findings of inflammatory myofibroblastic tumors of the head and neck

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare tumor of mesenchymal origin that commonly occurs in the lung. Because of its non-specific clinical and imaging features, IMT is often misdiagnosed as a malignant tumor. There have been few imaging reports on IMT of the head and neck.

PURPOSE

To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of inflammatory myofibroblastic tumors (IMTs) of the head and neck.

MATERIAL AND METHODS

Six patients with IMTs of the head and neck confirmed by histopathologic examination were analyzed retrospectively.

RESULTS

The mean patient age was 40 years. The tumor locations in the six patients were as follows: left bridge of the nose (one), right infratemporal fossa (two), and left parotid gland (three). Three patients who underwent CT all had soft tissue masses or nodules and no calcification. Bridge of the nose tumor showed a homogeneous isodense nodule and mild homogeneous enhancement. Infratemporal fossa tumor showed a homogeneous low density mass and intermediate homogeneous enhancement. Left parotid gland tumor showed a heterogeneous, mostly low density mass, and intermediate heterogeneous enhancement. T1-weighted images of the parotid gland tumors were hypointense; the infratemporal fossa tumor was isointense. T2-weighted images were mildly hypointense and of mixed hypo- and isointensity in the two parotid gland tumors; the infratemporal fossa tumor was homogeneously mildly hypointense. Heterogeneous intermediate enhancement was demonstrated in one parotid gland and the infratemporal fossa patients and mild homogeneous enhancement in another parotid gland patient.

CONCLUSION

The imaging features of IMTs of the head and neck are non-specific. An ill-defined, aggressive mass and variable enhancement on CT and MRI may suggest the diagnosis of IMT. IMT should be included in the differential diagnosis of regional tumors.

Inflammatory myofibroblastic tumor of the breast coexisting with breast cancer: a case report

BACKGROUND

The inflammatory myofibroblastic tumor (IMT) is an uncommon low-risk lesion with only a few cases described in the literature.

CASE REPORT

Here, we report a unique case of an IMT coexisting with breast cancer. Modified radical mastectomy was performed, followed by TAC chemotherapy (taxotere, adriamycin and cyclophosphamide). At the 2-year follow-up, the patient continues to be disease free.

CONCLUSION

At the preoperative stage, definitive diagnoses of masses are extremely difficult; surgery is advised only after the diagnosis is confirmed by pathological examination.

Inflammatory pseudotumor of the nasopharynx with spread along the trigeminal nerve

Inflammatory pseudotumor of the nasopharynx is a rare diagnosis that is often misinterpreted as carcinoma or lymphoma. It has been referred to as a tumefactive fibroinflammatory lesion, idiopathic pseudotumor, and fibrosing inflammatory pseudotumor. We present a rare case of a 40-year-old African American female from Kenya with inflammatory pseudotumor of the nasopharynx with perineural spread of disease along the trigeminal nerve to discuss the diagnosis and treatment of such an uncommon entity.

Long-term results of concurrent chemoradiotherapy for T3/T4 locally advanced nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is one of the most commonly diagnosed head and neck malignancies. This study investigated the outcome of locally advanced NPC patients on concurrent intensity-modulated radiation therapy (IMRT) and chemotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF). A total of 226 patients with locally advanced NPC received IMRT, with a total dose of 65-70 Gy and concurrent chemotherapy, with 2 cycles of TPF administered during radiotherapy, between March, 2005 and March, 2007. An additional 2 to 4 cycles of chemotherapy were administered every 21 days following radiotherapy. With a median follow-up time of 35 months (range, 7-60), the 5-year overall survival (OS) rate was 81.4%, with 93.6 and 75.0% for T3 and T4 lesions, respectively, (P=0.001). The 5-year progression-free survival (PFS) was 50.4%, with 66.7 and 46.9% for T3 and T4 lesions, respectively (P<0.001). T-classification was a significant prognostic factor for PFS and OS. The subgroup analysis revealed that pterygopalatine fossa invasion was associated with a significantly lower 5-year PFS (P=0.001) and OS (P=0.002), foramen rotundum invasion was associated with a significantly lower 5-year PFS (P<0.001) and OS (P=0.004), foramen ovale invasion was associated with a significantly lower 5-year PFS (P=0.013) and OS (P=0.024) and foramen lacerum and cavernous sinus invasion were associated with a significantly lower 5-year PFS (P<0.001 and P<0.001, respectively). Concurrent chemoradiotherapy is an advocated regimen for patients with locally advanced NPC, since it exhibits satisfactory 5-year PFS and OS rates. Our results suggest that the estimation of invasive range may identify a subgroup of patients with a higher risk of locoregional failure who may be better candidates for this treatment strategy.

MRI and CT of nasopharyngeal carcinoma

OBJECTIVE

This article reviews the MRI and CT of nasopharyngeal carcinoma. Extension of nasopharyngeal tumors, especially into the skull base and the deep facial spaces, is well illustrated on imaging. Assessment of retropharyngeal and cervical lymphadenopathy is important for treatment planning. MRI is commonly used for monitoring patients after therapy.

CONCLUSION

Imaging can detect effect of radiation on surrounding structures. The imaging findings that help to differentiate nasopharyngeal carcinoma from simulating lesions are discussed.

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.