Inflammatory myofibroblastic tumour of the maxillary sinus: CT appearance, clinical and pathological findings

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.

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 tumors of the nasal cavity and paranasal sinus: a clinicopathologic study of 25 cases and review of the literature

Inflammatory myofibroblastic tumor (IMT) is rare in nasal cavity and paranasal sinus. The aim of this study was to describe the clinicopathological features of sinonasal IMT and analyze the relationship between the clinicopathological features and the prognosis. A retrospective study of 25 IMT patients between 2001 and 2012 was performed. Data on clinical features, treatment, and follow-up were recorded. The histological characters were observed. Overall survival (OS) and event-free survival (EFS) were estimated using the Kaplan-Meier method. Clinically, the most common symptoms were nasal obstruction, facial pain, and toothache. Twenty patients received follow-ups 6-120 months after initial diagnosis. Fifteen (75 %) developed recurrence 1 or more times. One patient had left cervical lymph node metastasis (5 %). Five patients died of the tumor (25 %). Histologically, the IMTs composed of bland spindle cells admixed with a prominent infiltrate of plasma cells and lymphocytes and showed obvious atypia in recurrent cases. Histology with necrosis, mitosis (≥1/10 HPF), ganglion-like cells, histological pattern I or II and relapse (≥4 times) was significantly associated with poor OS and EFS. IMT of the nasal cavity and paranasal sinuses exhibits relatively bland histologic appearances, but can shows strongly aggressive behavior and relatively poor outcomes. Multiple relapse, necrosis, frequent mitosis, the presence of ganglion-like cells, and histological pattern might be associated with poor clinical outcomes.

Inflammatory myofibroblastic tumour of the maxillary sinus: CT and MRI findings

AIM

To characterize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of inflammatory myofibroblastic tumours (IMTs) of the maxillary sinus.

MATERIALS AND METHODS

The imaging findings of eight patients with IMTs of the maxillary sinus were reviewed retrospectively. Of the eight patients, four patients underwent unenhanced and contrast-enhanced CT, and one patient underwent unenhanced CT only; three patients underwent unenhanced and contrast-enhanced MRI.

RESULTS

Five cases of IMTs occurred in the left maxillary sinus, while three cases were right-sided. Four cases occupied the entire sinus, and the other four cases only partially occupied the sinus. Unenhanced CT images showed heterogeneous masses in four cases and a homogeneous mass in one case. One of the tumours showed some areas of calcification. T1-weighted MRI images showed isointense lesions. T2-weighted images showed mixed isointense and mild hyperintense lesions. All cases showed bone destruction and had infiltrated into the nasal fossa, orbit, infratemporal fossa, and other adjacent tissues. Seven cases showed mild to moderate heterogeneous enhancement on contrast-enhanced CT or T1-weighted MRI images.

CONCLUSION

IMTs of the maxillary sinus can be characterized as a soft-tissue mass with bony destruction and infiltration of the adjacent tissues, with mild to moderate enhancement after the injection of contrast medium. CT and MRI can help to diagnose IMTs, determine the extent of the lesion and its relationship with adjacent tissues, and thus facilitate the prediction of surgical resectability.

Inflammatory myofibroblastic tumor of the head and neck

Inflammatory myofibroblastic tumor (IMT) is a rare benign neoplasm. The aim of this study was to enhance the understanding of head and neck IMT and to improve its diagnosis and management. Clinical features and related treatment of 10 IMT cases were retrospectively analyzed and the literature was reviewed. Tumor sites identified included four in the maxillary space, two in the buccal space, two in the parotid gland, one in the post aurem, and one in the neck. Nine of ten patients received local resection, and one of ten patients received a total maxillectomy. One patient had a local recurrence and died, while the other nine patients had no distant metastases and survived. A computed tomography (CT) exam performed on nine of the ten patients showed that six of these nine cases were heterogeneous in density, while the other three cases were homogeneous. Four cases showed marked heterogeneous enhancement, two cases showed mild heterogeneous enhancement, and three cases showed moderate homogeneous enhancement on contrast-enhanced CT images. The incidence of IMT in the head and neck is low, and local resection is currently the best treatment. A prolonged postoperative follow-up period is necessary for patients with IMT.