Intracranial inflammatory myofibroblastic tumor with negative expression of anaplastic lymphoma kinase: a case report and review of the literature.

Inflammatory myofibroblastic tumor (IMT) is an indolent tumor mainly affecting children and young adults. As a rare mesenchymal tumor with unknown etiology and pathogenesis, IMT has a predilection for lung and abdominopelvic region. Previous literature featuring on IMT in the central nervous system (IMT-CNS) was rare. The clinical symptoms and radiological features of IMT-CNS are not specific, and therefore the diagnosis is predominately based on the histopathological and immunohistochemical analysis of the specimen. We herein present a case of a 21-year-old woman who complained of bilateral blurred vision for 15 days. The head magnetic resonance imaging (MRI) demonstrated a round-shaped and irregular lesion located in the right frontal lobe. The boundary of the lesion was clear and lesion was homogeneously enhanced. Peripheral edema of the lesion was observed and the mass effect was obvious. Supratentorial craniotomy tumor resection was performed. Histopathological and immunohistochemical analysis revealed IMT which had negative expression of anaplastic lymphoma kinase (ALK). Remission of her symptoms was observed and no recurrence was recorded during a 6-month follow-up.