Inflammatory pseudotumour involving the skull base and cervical spine

Intradural-extramedullary inflammatory pseudotumour of the cervical spinal cord of a dog

An 8-year-old mixed-breed dog was presented with cervical hyperesthesia, tetraparesis, and mild proprioceptive ataxia in all four limbs. 3 Tesla MRI showed a dorsal compressive intradural-extramedullary mass at the level of C1-C2, isointense to the gray matter with a hypointense ventral core on T2 weighted images (WI), isointense on T1WI, with a strong and homogeneous contrast enhancement. A C1-C2 partial dorsal laminectomy was performed, and the lesion was removed en bloc. The histopathological and immunohistochemical analysis defined the diagnosis of inflammatory pseudotumor.

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.

A rare case of inflammatory pseudotumor located in the ventral of medullocervical junction. A case report and review of literature

Inflammatory pseudotumor is a benign lesion of unknown etiology, which mimics neoplasms clinically and radiographically. It most commonly involves the lungs and orbits and is rarely reported in the central nervous system. We report a rare case of inflammatory pseudotumor located in the ventral junction of the medulla oblangta and cervical cistern, which has not been reported before as far as we know. A 61-year-old male presented with right arm weakness. MRI showed a mass located in the ventral junction of the medulla oblongata and cervical cisten. The patient was diagnosed as inflammatory pseudotumor(IPT) after surgical excision and histopathology. This tumor-like lesion was surrounding the bilateral intracranial segment of the vertebral arteries. No evidence of vascular invasion was observed. Complete surgical resection was achieved.

Inflammatory myofibroblastic tumor of bone harboring an ALK gene amplification

Inflammatory myofibroblastic tumor (IMT) is a neoplastic proliferation of myofibroblastic/fibroblastic cells with a variable admixture of inflammatory cells. It primarily affects soft tissue and viscera of children and young adults. IMT occurring in bone is extremely rare. Approximately 50% of IMTs carry a clonal rearrangement of the anaplastic lymphoma kinase (ALK) gene, while other receptor tyrosine kinase gene rearrangements have been seen in a small subset of IMT. Herein, we report the first case of IMT which harbors an ALK gene amplification rather than a rearrangement thus resulting in overexpression of the protein, arising from the femur of a 24-year-old man. Our case provides a novel pathogenesis for IMT. An overview of cytogenetic abnormalities of IMT is also integrated into this report.

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.

Odontoid pseudotumor and serial postfusion radiographic evaluation in a patient with a C1–2 mass

Odontoid pseudotumor is a mass occurring around the odontoid process in the cervical spine and can cause significant neurological symptoms at the craniocervical junction due to compression of the spinal cord and cervicomedullary junction at this level. A literature review was performed to provide input on options for treatment and prognosis for this lesion. The literature search found 12 papers in which pseudotumor was treated with posterior decompression and fixation. Posterior decompression and fixation with serial imaging to monitor the size of the pseudotumor postsurgery is a safe and effective treatment option for odontoid pseudotumors.

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.

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.

Inflammatory myofibroblastic tumor of the temporal bone: a histologically nonmalignant lesion with fatal outcome

INTRODUCTION

Inflammatory myofibroblastic tumor (IMFT) of the temporal bone is an unusual but distinct clinicopathologic entity.

CASE REPORT

We report the case of a 75-year-old patient with an IMFT located in the temporal bone. Symptoms included VI, X, XI, and XII cranial nerves palsies. Computed tomography and magnetic resonance images are described. The lesion was locally aggressive and outcome was fatal. IMFT was identified by analysis of postmortem specimen with histopathologic and immunohistochemical confirmation.

DISCUSSION

IMFT can be locally destructive lesions. Involvement of the skull base and cervical spine is indistinguishable from an aggressive infection or a malignant tumor and can be fatal as in our case report. The difficulties in establishing clinicopathologic diagnosis, radiological imaging characteristics, and treatment are discussed.

Inflammatory myofibroblastic tumor of bone: two cases occurring in long bone

Inflammatory myofibroblastic tumor (IMT) is an unusual tumor composed of differentiated myofibroblastic spindle cells usually accompanied by numerous plasma cells and lymphocytes. IMT was originally described in the lung; occurrence in a long bone is rare. We present two examples of IMT arising in a long bone: one in the humerus and one in the femur. In both cases, imaging shows a poorly delineated osteolytic lesion with cortical bone destruction that aggressively extends into surrounding soft tissue. Histologically, the lesion is dominated by differentiated spindle cells with aprominent collagenous stroma and an inflammatory component including plasma cells and lymphocytes, and with positive immunoreactivity for anaplastic lymphoma kinase. The absence of cytologic atypia helps differentiate this lesion from malignant spindle cell tumors.

Imaging of nasopharyngeal inflammatory pseudotumours: differential from nasopharyngeal carcinoma

The purpose of this study was to describe the MRI findings of inflammatory pseudotumours (IPTs) involving the nasopharynx and to differentiate IPTs from nasopharyngeal carcinoma (NPC). The medical records and imaging studies of 7 patients (6 men, 1 woman; age range, 32-71 years; mean age, 52.4+/-18 years) with IPT involving the nasopharynx were reviewed retrospectively. The MRI findings were compared with those of seven patients with advanced NPC with skull base invasion. All patients with IPT involving the nasopharynx presented with single or multiple cranial neuropathies; six reported pain; and four patients had a recent history of otitis media. Three were initially misdiagnosed as having NPC according to MRI findings, and all underwent nasopharyngeal biopsy to exclude malignancy. 7/7 (100%) patients received systemic corticosteroid treatment; 7/7 (100%) showed initial rapid resolution of clinical symptoms or radiographical findings; 3/7 (42.9%) had resolution of all signs and symptoms; 3/7 (42.9%) still have limited residual symptoms; and 1/7 (14.3%) suffered recurrence 3 years after remission. The characteristic MR findings of IPT include an infiltrative growth pattern, minimal to mild mass effect, hypointensity on T(2) weighted images, and moderate homogeneous enhancement after contrast administration. Intact nasopharyngeal mucosa, internal carotid artery encasement and narrowing, extensive pachymeningeal thickening and a relative paucity of associated neck lymphadenopathy are additional MR findings that favour the diagnosis of IPT rather than NPC. In conclusion, IPT involving the nasopharynx has characteristic MR findings which, together with clinical and laboratory presentations, are helpful in differentiating IPT from malignant tumours, especially NPC.

Sphenoid wing inflammatory pseudotumor mimicking a clinoidal meningioma: case report and review of the literature

BACKGROUND

Inflammatory pseudotumor is a nonneoplastic process of unknown etiology most frequently involving the lungs and orbits. Primary intracranial inflammatory pseudotumors are exceptionally rare. The authors report a rare case of clinoidal inflammatory pseudotumor mimicking a medial sphenoid wing meningioma.

CASE DESCRIPTION

A 24-year-old woman presented with visual diminution and proptosis in the left eye for one and a half years. Imaging revealed a medial sphenoid wing mass, which was surgically decompressed. Histopathology confirmed the diagnosis of inflammatory pseudotumor after which she was treated with steroids. The patient is doing well at 3 months' follow-up with resolution of proptosis and no further diminution of vision.

CONCLUSION

Inflammatory pseudotumors can mimic a malignant tumor both radiologically and clinically. The treatment options consist of surgery, high-dose steroids, irradiation, and chemotherapeutic agents with variable therapeutic response. Intracranial involvement due to inflammatory pseudotumor is exceptionally rare. The importance of recognizing and appropriately diagnosing this rare intracranial pathology lies in prognostication and avoidance of overzealous treatment.

Inflammatory pseudotumor of the cavernous sinus and skull base

Inflammatory pseudotumor is a non-neoplastic process of unknown etiology characterized by a proliferation of connective tissue with an inflammatory infiltrate. Intracranial inflammatory pseudotumors classically involve the cavernous sinus but can also occur in the supratentorial or infratentorial compartments and spinal canal. Symptoms are dependent on location, and, when present in the cavernous sinus, typically include cranial nerve palsies of those nerves in the cavernous sinus. These lesions are rapidly responsive to steroid therapy. Surgery is typically indicated for biopsy only, but complete resection may be justified for lesions outside the cavernous sinus.

Oral inflammatory myofibroblastic tumor demonstrating ALK, p53, MDM2, CDK4, pRb, and Ki-67 immunoreactivity in an elderly patient

Inflammatory myofibroblastic tumor (IMT) is a controversial lesion composed of myofibroblasts, accompanied by varying numbers of inflammatory cells. Various pathogenetic factors have been proposed (ie, reactive, infectious, autoimmune, and neoplastic) but the etiology of most IMTs remains unknown. Here we review the literature of oral IMTs, detailing the demographic profile of these rare lesions. Moreover, we present an unusual case of IMT arising from the mandibular alveolar mucosa of an 82-year-old female. Microscopic examination revealed plump spindle cells set in a myxoid vascular stroma admixed with inflammatory cells. Numerous large ganglion cell-like cells were seen, some exhibiting emperipolesis of neutrophils. Ultrastructurally, prominent myofibroblasts with abundant rough endoplasmic reticulum were noted. Tumor cells were immunoreactive for vimentin, smooth muscle actin, and KP1 (CD68), and negative for desmin, S-100, and EBV-LMP. The lesion was excised without margins and the patient has manifested no evidence of disease at an 18-month recall. In an attempt to further delineate the potential neoplastic nature of this lesion, we assessed the immunohistochemical expression of various markers that have been linked to neoplastic transformation. The recorded positivity for ALK, p53, MDM2, CDK4, pRb, and Ki-67, despite the absence of bcl-2 reactivity, strongly favors the neoplastic origin of the studied tumor.

Inflammatory Pseudotumor of the Temporal Bone

OBJECTIVE

To characterize the clinical presentation, imaging characteristics, intraoperative findings, and key histopathologic features of inflammatory pseudotumors of the temporal bone. Findings from an index case are presented, and the literature is reviewed for comparison.

STUDY DESIGN

Retrospective case review.

SETTING

University tertiary referral center.

PATIENTS

Cases were identified by review of surgical specimens from the temporal bone and lateral skull base with histopathologic confirmation. A single case was identified at our institution. Nine additional cases were identified in the literature; clinical features were reviewed.

INTERVENTION

Of reported cases, treatment consisted of complete surgical excision in eight cases and subtotal excision in one. The index patient underwent surgical excision with postoperative corticosteroid therapy for adjacent meningeal involvement, after histopathologic interpretation. Corticosteroids were administered to one patient with residual microscopic tumor, and external beam radiotherapy was used for residual/recurrent disease in one case.

RESULTS

The lesions were typically locally aggressive with extensive bony erosion. Three cases (33%) demonstrated labyrinthine and otic capsule involvement. Four cases (44%) involved the facial nerve. Characteristic histopathologic features included fibroblastic proliferation and a mixed inflammatory cell infiltrate in all cases. Mitotic figures, nuclear pleomorphism, and necrosis were rare or nonexistent.

CONCLUSIONS

Inflammatory pseudotumors of the temporal bone are rare but aggressive lesions. Therapy should consist of surgical excision with steroids reserved for residual or intracranial disease or in patients in whom surgery is not an option. These lesions must be differentiated from other infectious, granulomatous, and neoplastic lesions on the basis of histopathologic and immunohistochemical findings.