Inflammatory myofibroblastic tumour: a rare entity with wide differential diagnosis.

Inflammatory myofibroblastic tumour (IMT) is a rare, distinctive mesenchymal neoplasm. Grossly, it appears as a circumscribed mass with a rubbery to firm cut surface. Microscopically, it is characterized by a spindle cell proliferation within a myxoid stroma with admixed plasma cells, lymphocytes and eosinophils. Immunohistochemical staining is usually positive for vimentin, smooth muscle actin (SMA) and anaplastic lymphoma kinase (ALK). ALK gene rearrangement is present in approximately 50-70% IMTs. The standard treatment is surgical resection, and it is essential to differentiate IMT from benign and malignant mimickers so that appropriate therapy may be provided. Clinical and radiological follow-up is required to detect recurrence.