Inflammatory myofibroblastic tumour, also known as inflammatory pseudotumour and inflammatory fibrosarcoma, is a soft tissue

Soft tissue

In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...

 lesion that may be confused with a sarcoma

Sarcoma

A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...

. It is abbreviated IMT.

Symptoms

The symptoms depend on the specific location of the tumour, which can be anywhere in the body.

Diagnosis

Inflammatory myofibroblastic tumours are diagnosed based on their appearance under the microscope

Microscope

A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

, by pathologists. Medical imaging

Medical imaging

Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...

 findings are non-specific.

Pathology

Inflammatory myofibroblastic tumour are characterized by a mix of inflammatory cells, e.g. plasma cells, lymphocytes and eosinophils, and bland spindle cells without nuclear atypia

Nuclear atypia

Nuclear atypia refers to abnormal appearance of cell nuclei. It is a term used in cytopathology. Specific abnormalities include pleomorphism....

. These tumours may have necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

, hemorrhage, focal calcification

Calcification

Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...

 and mitotic activity.

The histologic differential diagnosis includes calcifying fibrous pseudotumour, inflammatory fibroid tumour and nodular fasciitis

Nodular fasciitis

Nodular fasciitis, also known as nodular pseudosarcomatous fasciits, pseudosarcomatous fasciitis, and subcutaneous pseudosarcomatous fibromatosis, is a benign soft tissue lesion most commonly found in the superficial fascia. It is most common in young persons on the upper extremities and trunk,...

.

Approximately half of IMTs have a rearrangement of the ALK gene

Anaplastic lymphoma kinase

Anaplastic lymphoma kinase also known as ALK tyrosine kinase receptor or CD246 is an enzyme that in humans is encoded by the ALK gene.-Function:...

.