MRI characterization of inflammatory myofibroblastic tumors in the maxillofacial region

Abstract

HEAD AND NECK IMAGINGORIGINAL ARTICLE 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 METHODSTen 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. RESULTSOf 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. CONCLUSIONIMTs 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 tumors (IMTs) are rare neoplasms composed of myofibroblasts accompanied by prominent small lymphocytes and plasma cells (1). They have previously been categorized in the inflammatory pseudotumor group, but they are now defined as a separate entity based on electron microscope and immunohistochemical findings. Recent studies have shown that cytogenetic clonal abnormalities and anaplastic lymphoma kinase expression are the best definitive markers for diagnosing IMTs (2, 3). IMTs most commonly involve the lung, although they have been described in almost all sites in the body, in both sexes, and at all ages (4). IMTs in the maxillofacial region are exceptionally rare, and the clinical presentation depends on the location of the tumor. Patients can present with fever, pain, swelling, otorrhea, and cranial nerve palsy (5). IMTs clinically mimic malignant lesions, and the clinical significance lies in the difficulty encountered in excluding malignancy, preoperatively. There have been only a few studies that reported substantial numbers of IMTs in the maxillofacial region. Recently, Yuan et al. (6) reported imaging findings for eight IMT cases in the maxillary sinus; however, only three of the patients underwent MRI analysis, and the researchers could not summarize the MRI characteristics. Therefore, we have retrospectively analyzed the MRI findings of ten cases with maxillofacial IMT and summarized the imaging features in order to improve the diagnosis of this tumor. Material and methods PatientsA total of ten patients with pathologically confirmed IMTs in the maxillofacial region were reviewe...

Inflammatory Myofibroblastic Tumour of the Submandibular Gland

“…IMTs in the head and neck region are rare with the specific incidence of submandibular gland IMTs not being clear. Lymphocytes, plasma cells, histiocytes, fibroblasts and myofibroblasts are the basic components of IMT, present in variable proportions [8]. The aetiology and pathogenesis of IMTs remains unclear.…”

“…In the head and neck case reports in the parapharyngeal spaces, maxillary sinuses, epiglottis and oral cavity are well documented [4]. Radiologically, IMTs of the head and neck tend to be non-specific, only showing lesion size or infiltrative or aggressive behaviour [8].…”

Diffuse Parotid Swelling From an Underlying Parotid Mass in a Pediatric Patient

“…IMT frequently exhibits local invasion, similar to aggressive malignant neoplasms. 7 On computed tomography imaging, IMT demonstrates a homogeneous or heterogeneous contrast-enhanced soft-tissue mass with frequent extension into adjacent tissue. 8 The differential diagnosis for IMT includes benign lesions like nodular fasciitis, myofibroma, and neural and smooth muscle lesions.…”

“…On T2-weighted images it is generally hypointense or slightly hyperintense and exhibits strong enhancement on contrast-enhanced T1-weighted images. IMT frequently exhibits local invasion, similar to aggressive malignant neoplasms . On computed tomography imaging, IMT demonstrates a homogeneous or heterogeneous contrast-enhanced soft-tissue mass with frequent extension into adjacent tissue…”

Case Report: Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Application in Intraperitoneally Disseminated Inflammatory Myofibroblastic Tumor and in the Youngest Patient in the World: New Indication and Modification of Technique

“…These tumors consist of spindle-shaped myofibroblastic cells accompanied by inflammatory infiltration of plasma cells, lymphocytes, and eosinophils. IMT is characterized by a low mitotic index, no atypical division figures, necrosis, nuclear atypia, and above all, it seems not to spread through blood vessels (5). IMT can be a result of genetic mutation, or secondary to infectious or autoimmune disease.…”