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

Abstract

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.

Keywords: ALK; Inflammatory myofibroblastic tumor; Pediatric tumors; Seizure.