Case 185: inflammatory myofibroblastic tumor

Inflammatory myofibroblastic tumor of the lung involving the central nervous system in pediatric patients

INTRODUCTION

The inflammatory myofibroblastic tumor (IMT) is a very rare lesion with an incidence of less than 0.1% of total neoplasms and with main affection in the lungs. Involvement in the central nervous system is extremely rare, but with a much more aggressive course than IMT diagnosed in the rest of the body. We report the 2 cases presented in our neurosurgery department to date; both were treated satisfactorily without intercurrences in 10 years of follow-up.

HISTORICAL BACKGROUND

The World Health Organization described the IMT as a distinctive lesion composed of myofibroblastic spindle cells accompanied by an inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils.

CLINICAL PRESENTATION

Clinical manifestations of patients with CNS IMT vary and may consist of headache, vomiting, seizures, and blindness. Seizures are the most common symptom in patients with focal lesions.

DIAGNOSIS

The true origin of this entity remains to be elucidated, but to date, etiologies ranging from chromosomal alterations to autoimmune or postinfectious mechanisms have been described. Due to its rarity and non-specificity in imaging, the final diagnosis of IMT in the brain parenchyma relies on pathological examination.

MANAGEMENT

Treatment options are controversial and include total or subtotal removal, high-dose steroids, and radiation therapy. In the last decade, the development of ALK Tyrosine Kinase Inhibitors allows the possibility of chemotherapy in those patients harboring ALK mutations.

CONCLUSION

IMT is a rare tumor that can exceptionally be found in the CNS. The cause is still unknown although the different studies focus on a neoplastic origin. The diagnosis is based in the use of different modalities of imaging and with histological confirmation. Optimal management is gross total resection whenever possible, is the only established curative treatment. Further research with longer follow-up is needed to clarify the natural history of this rare tumor.

Radiological diagnostic dilemma in a child with small aggressive facial mass, time to increase the differentials: an inflammatory myofibroblastic tumour

A 5-year-old girl with left facial swelling in the medial maxillary region close to the nasal ala was brought by her parents to our head and neck clinic. They have visited other doctors for similar presentation in the last 6 months, which started as redness and swelling, with occasional epiphora. The redness resolved after medical treatment, with slight regression of swelling, although it did not disappear. CT and MRI showed a locally aggressive, small enhancing soft tissue mass involving the left anteromedial maxillary wall, the nasal bone and the orbital floor. The mass involved the bony course of the nasolacrimal duct, which was the aetiology of the epiphora. The head and neck team performed an incisional biopsy through a sublabial approach. Concurrently, a nasolacrimal duct stent was inserted by an ophthalmologist. Histopathology was consistent with inflammatory myofibroblastic tumour with positive stains for CD68, CD163 and anaplastic lymphoma kinase-1. The tumour was excised and presently the patient is on periodic follow-up with head and neck and ophthalmology clinics.

Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor

Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery.