Inflammatory myofibroblastic tumour of the skull base

Inflammatory myofibroblastic tumor from molecular diagnostics to current treatment

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with intermediate malignancy characterized by a propensity for recurrence but a low metastatic rate. Diagnostic challenges arise from the diverse pathological presentation, variable symptomatology, and lack of different imaging features. However, IMT is identified by the fusion of the anaplastic lymphoma kinase (ALK) gene, which is present in approximately 70% of cases, with various fusion partners, including ran-binding protein 2 (RANBP2), which allows confirmation of the diagnosis. While surgery is the preferred approach for localized tumors, the optimal long-term treatment for advanced or metastatic disease is difficult to define. Targeted therapies are crucial for achieving sustained response to treatment within the context of genetic alteration in IMT. Crizotinib, an ALK tyrosine kinase inhibitor (TKI), was officially approved by the US Food and Drug Administration (FDA) in 2020 to treat IMT with ALK rearrangement. However, most patients face resistance and disease progression, requiring consideration of sequential treatments. Combining radiotherapy with targeted therapy appears to be beneficial in this indication. Early promising results have also been achieved with immunotherapy, indicating potential for combined therapy approaches. However, defined recommendations are still lacking. This review analyzes the available research on IMT, including genetic disorders and their impact on the course of the disease, data on the latest targeted therapy regimens and the possibility of developing immunotherapy in this indication, as well as summarizing general knowledge about prognostic and predictive factors, also in terms of resistance to systemic therapy.

Inflammatory Myofibroblastic Tumor of the Testis in a Patient With Cecal Carcinoma

Inflammatory myofibroblastic tumors (IMTs) are uncommon tumors that can be classified among fibroinflammatory disorders. IMTs are diagnosed after excluding all other entities, which can be considered differential diagnoses of IMTs. Microscopic examination of IMTs shows multiple myofibroblastic spindle cells, which are surrounded by inflammation. IMTs have lesser chances of progression to malignancy. The case defined below is one of the few cases in the literature that reports the presentation of IMT and another malignancy. We describe a 72-year-old man who was found to have cecal carcinoma and later diagnosed with an IMT of the testis. IMTs are generally benign tumors with a tendency for local recurrence. Patients affected by IMTs usually get diagnosed only after more than one biopsy. IMT is diagnosed only after ruling out other differential diagnoses. They rarely show invasiveness and metastasize. The presence of metastasis, recurrence, and other malignancies probably indicate poor prognosis and poor survival. The course of IMTs is usually benign, with good outcomes after surgery. IMTs have been known to recur, invade, or metastasize in sites such as paranasal sinuses, mediastinum, and the abdomen. In the case that we researched, vimentin and smooth muscle actin were strongly positive in the spindle-shaped cells, whereas anaplastic lymphoma kinase-1 was negative.

Advanced MRI features of intraventricular inflammatory myofibroblastic tumor: a case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare central nervous system (CNS) tumor. We first report a rare case of IMT in the lateral ventricle and describe the magnetic resonance imaging (MRI) findings of the tumor with an emphasis on the advanced MRI features.

CASE PRESENTATION

A 49-year-old female patient with headaches and blurred vision for 2 months. Brain MRI revealed a well-circumscribed, lobulated mass occupying the left lateral ventricle trigone, with marked perilesional brain edema. The tumor showed heterogeneous significant hyperintensity on T2-weighted imaging (T2WI) and hypointensity on T1-weighted imaging (T1WI). After the administration of gadolinium, the mass exhibited marked contrast enhancement and the halo sign was observed. On advanced MRI, the lesion showed decreased perfusion on perfusion MRI and reduced diffusion on diffusion-weighted imaging (DWI). On susceptibility-weighted imaging (SWI), there was a punctate low signal intensity in the tumor. The patient underwent surgical resection of the mass and a pathological examination confirmed the lesion to be an inflammatory myofibroblastic tumor with negative expression of anaplastic lymphoma kinase (ALK). This patient had remained healthy without evidence of recurrence during a 20-month follow-up.

CONCLUSIONS

On MRI, marked perilesional brain edema, significant hyperintensity on T2WI, hypoperfusion on perfusion MRI but with an obvious enhancement, no diffusion restriction on DWI, and halo sign may be the characteristic findings of intraventricular IMT. The advanced MRI characteristics could provide abundant information to reflect the histological features and physiological metabolic characteristics of the tumor.

Inflammatory Myofibroblastic Tumour of the Sinonasal Tract with Orbital and Intracranial Extensions Simulating a Malignancy: A Case Report and Review of Literature

Inflammatory Myofibroblastic Tumour (IMT) is a rare pathology of unknown etiology. It is pathologically benign, but clinically locally invasive. We are herewith reporting a unique case of rapidly growing sinonasal IMT with orbital and intracranial extensions in a middle aged female patient masquerading as a malignancy. The lesion was excised endoscopically with margins and the patient is presently under close follow up. The report also reviews the common sites of involvement and management options available, based on a literature review.

Inflammatory myofibroblastic tumor of the lumbar spinal canal: A Case Report With Literature Review

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is a rare type of mesenchymal tumor. IMT can arise in multiple anatomic locations. IMT of the lumbar spinal canal is exceptionally rare.

PATIENT CONCERNS

Here, we report the case of a 56-year-old male patient with an IMT who was in good health until 1 year prior to admission, when he began experiencing pain in both lower extremities and the lower back.

INTERVENTIONS

A space-occupying lesion in the lumbar canal was identified by magnetic resonance imaging and then surgically resected.

DIAGNOSES

Histopathological analysis of the lesion revealed a composition of mucous edema, inflammatory cells, collagenous fibers, and spindle cells that were diffuse and positive for smooth muscle actin and CD68; focal positive for vimentin and desmin; and negative for CD34 (marker of vascular endothelial cells), CD21, CD23, CD35, S-100, Epstein-Barr virus infection, Ki-67, and anaplastic lymphoma kinase. Thus, the diagnosis was an IMT of the lumbar canal.

OUTCOMES

In the spinal canal, IMT should be considered in the evaluation of tumors although it is a very rare diagnosis. It is a benign lesion, but it has potential for invasion and recurrence.

LESSONS

There are no characteristic imaging features of these tumors, but they can be addressed by complete surgical excision. Patients with these lesions should undergo frequent long-term follow-up to detect and address recurrence.

Sinonasal Inflammatory Myofibroblastic Tumor with Anaplastic Lymphoma Kinase 1 Rearrangement: Case Study and Literature Review

Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal tumors initially described in the lung. About half of them exhibit expression of the ALK1 protein, generally resulting from a gene rearrangement. Paranasal sinus IMTs are extremely uncommon, and gene rearrangement of ALK1 is very rare in this localization. A 47-year-old woman presented with rapidly progressive vision loss in her left eye. Clinical and imaging work-up revealed a tumor invading the left ethmoidal and sphenoidal sinuses and extending into the nasal cavity, the orbit and the skull base. Complete tumor resection was performed using an endonasal approach. Pathological examination revealed a paranasal localization of IMT, positive for ALK1 immunostaining. FISH analysis showed an ALK1 gene rearrangement. This case illustrates the local aggressive potential for IMTs. Treatment is primarily surgical, but targeted therapies (crizotinib) might be a solution for ALK1 rearranged cases with a poor prognosis.

Surgical management and follow-up of lateral skull base tumors: An 8-year review

The purpose of the present article was to describe the diagnostic evaluation of, and surgical approaches to, lateral skull base tumors (LSBTs). The study is a retrospective review of 21 patients diagnosed with tumors that involve lateral skull base (8 with malignant diseases and 13 with benign lesions) who were surgically treated during a 8-year period. The transparotid-transmandibular (38%) was the most commonly performed surgical procedure, followed by the transmandibular (24%), the transmaxillary (24%), the transcervical approach (10%) and the combined approach (4%). The surgical procedures were uneventful and there were no postoperative mortalities. Complications were encountered in 12 cases, and morbidity was not remarkable during the perioperative stages. After an average follow-up of 46 months, only 1 of 14 patients with benign diseases had a recurrence following the resection of a pleomorphic adenoma. Of 7 patients with malignant tumors, 5 are alive with no evidence of disease. The majority of the benign lateral skull base tumors can be removed surgically with a low rate of complications and recurrence. However, malignant neoplasms carry a poor prognosis and a low rate of disease-free survival.

MRI characterization of inflammatory myofibroblastic tumors in the maxillofacial region

PURPOSE

We aimed to investigate the magnetic resonance imaging (MRI) appearance of inflammatory myofibroblastic tumors (IMTs) in the maxillofacial region in order to improve diagnostic quality and resection efficacy.

MATERIALS AND METHODS

Ten cases of pathologically identified IMTs were analyzed by MRI. The MRI features were examined, including tumor location, tumor shape, tumor margins, and involvement of the surrounding tissues.

RESULTS

Of ten masses investigated in this study, eight masses were irregular neoplasms with unclear margins and two masses, in the parotid gland, were regular neoplasms with clear margins. Precontrast T1-weighted images of all ten masses exhibited isointense signals compared to the adjacent tissue, while contrast-enhanced T1-weighted images showed strong enhancement. Six masses were hypointense and four masses were slightly hyperintense in T2-weighted images. Involvement of the adjacent structures was observed in eight of ten cases. Meanwhile, two patients experienced intracranial involvement.

CONCLUSION

IMTs are rare tumors in the maxillofacial region, displaying a number of distinct MRI characteristics. Most importantly, they display low T2 signal intensity and strong enhancement, and they frequently invade surrounding structures. Thus, MRI can improve the accuracy of IMT diagnoses and provide critical information for surgical planning.

Inflammatory Myofibroblastic Tumor of the Left Sphenoid and Cavernous Sinus Successfully Treated with Partial Resection and High Dose Radiotherapy: Case Report and Review of the Literature

Inflammatory myofibroblastic tumors, also known as plasma cell granulomas or inflammatory pseudotumors, are uncommon lesions that are known to arise in many areas of the body. They are uncommonly found in the skull base region where effective treatment can be difficult. Steroids and radiation therapy with gross total excision when possible remain the treatments of choice. However, the dosing of radiation remains controversial and many patients develop relapse despite medical management. We present the case of a patient who had an inflammatory myofibroblastic tumor of the sphenoid bone and cavernous sinus. He underwent partial surgical resection and transient steroid therapy. This was followed by high-dose fractionated radiotherapy. The patient demonstrated significant resolution in symptomatology and evidence of disease-free progression on repeat imaging. 

Recurrent inflammatory myofibroblastic tumor of the inguinal region: A case report and review of the literature

Inflammatory myofibroblastic tumors (IMTs) of the inguinal region are exceptionally rare. The current study reported the case of a 49 year-old male patient with IMT, who presented with a fever, night sweats, anorexia, loss of weight and frequent urination. Computed tomography (CT) revealed a lesion occupying the soft tissue of the right inguinal region and surgery was performed to resect the lesion. Histopathological analysis of the lesion revealed a composition of spindle and inflammatory cells, including plasma cells and lymphocytes. In addition, immunohistochemical analysis demonstrated that the tumor cells were positive for CD34, vimentin, actin, Ki-67, B cell lymphoma-2, CD99, epithelial membrane antigen and CD38; however, tumor cells were negative for CD117, desmin, anaplastic lymphoma kinase and creatine kinase. Thus, the patient was diagnosed with IMT and was advised to return for regular follow-up appointments. Subsequently, the patient developed a local recurrence 12 months following the initial surgery. Of note, the histopathological characteristics of the recurrent lesions were consistent with those of the initial specimen. Thus, a second surgery was performed, followed by fractionated radiotherapy (FRT). At 3 and 6 months following the FRT, magnetic resonance imaging scans did not indicate tumor recurrence or metastasis. In conclusion, surgical excision is the current recommended treatment for IMT; however, for cases similar to that of the current study, which are not successfully controlled by surgical excision, radiotherapy should be considered and long-term follow-up is essential.

Maxillary sinus inflammatory myofibroblastic tumors: a review and case report

An inflammatory myofibroblastic tumor (IMT) is an immunohistochemically diverse entity demonstrating neoplastic and nonneoplastic qualities. Although IMTs can arise in any area of the body, lesions arising in certain sites, namely, the nasal cavity, paranasal sinuses, and pterygopalatine fossa, demonstrate a heightened neoplastic and invasive potential. Despite case specific complete tumor regression and disease remission in response to pharmacotherapeutics, a subset of IMTs remain resistant to all forms of therapy. We present such a case, a 34-year-old female patient, with a highly resistant, maxillary sinus IMT. Her refractory, ALK-1 negative IMT has not responded well to novel therapies reported in current literature. This case suggests the role of zonal expressivity within a single lesion as a probable mechanism for its highly resistant nature and should promote determination of each IMT's cytogenetic profile to provide more effective targeted therapy. Paper includes a literature review of all maxillary sinus IMTs from 1985 to 2014 along with their immunohistochemical staining, treatments, and outcomes.