Inflammatory myofibroblastic tumour

A rare type of tumor composed of myofibroblastic spindle cells and inflammatory cells

Inflammatory myofibroblastic tumour (IMT) is a rare type of tumor that is characterized by the proliferation of myofibroblastic spindle cells accompanied by a prominent inflammatory infiltrate. These tumors can occur in various parts of the body and are most commonly found in the lungs, abdomen, and pelvis. IMTs are considered to be of intermediate biological potential, meaning they can recur locally and, in rare cases, metastasize.

Pathophysiology

IMTs are composed of spindle-shaped myofibroblasts, which are cells that have features of both fibroblasts and smooth muscle cells. These tumors are also characterized by a significant inflammatory component, which includes lymphocytes, plasma cells, and eosinophils. The exact cause of IMT is not well understood, but some cases have been associated with genetic rearrangements involving the ALK gene on chromosome 2p23.

Clinical Presentation

The clinical presentation of IMT varies depending on the location of the tumor. In the lungs, patients may present with cough, chest pain, or shortness of breath. Abdominal IMTs may cause pain, swelling, or gastrointestinal symptoms. Systemic symptoms such as fever, weight loss, and malaise can also occur due to the inflammatory nature of the tumor.

Diagnosis

The diagnosis of IMT is typically made through a combination of imaging studies and histopathological examination. Imaging techniques such as CT scans and MRIs can help determine the size and location of the tumor. A definitive diagnosis is made by biopsy, where the characteristic histological features of spindle cells and inflammatory infiltrate are observed.

High magnification image of an inflammatory myofibroblastic tumour showing spindle cells and inflammatory infiltrate

Treatment

The primary treatment for IMT is surgical resection, which is often curative. Complete removal of the tumor is the goal to prevent local recurrence. In cases where the tumor cannot be completely resected, or if it recurs, additional treatments such as corticosteroids, nonsteroidal anti-inflammatory drugs, or targeted therapies like ALK inhibitors may be considered.

Prognosis

The prognosis for patients with IMT is generally favorable, especially when the tumor is completely resected. However, the potential for local recurrence exists, and in rare cases, the tumor can metastasize. Long-term follow-up is recommended to monitor for recurrence.

Related pages

• Myofibroblast
• Tumor
• Inflammation
• ALK gene