대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Inflammatory myofibroblastic tumor

Radiologic Findings

Fig 1. There is about 2cm sized thin walled cavity in RULZ.
Fig 2. Consolidation surrounding cavitary lesion in RULZ.
Fig3-6. There is cavitary lesion in RUL with peripheral GGO halo. Cavitary wall is smooth and thin and there are thin septa within cavity.

The patient underwent RUL lobectomy and diagnosis was consistent with inflammatory myofibroblastic tumor with borderline malignancy in clinical behavior. ALK was positive and IgG4 was negative.

Brief Review

Inflammatory myofibroblastic tumor (IMT), also known as inflammatory pseudotumor, is a rare tumor with unknown etiology. It can involve many anatomic sites and most commonly affects the lung.
It affects predominantly younger population, and it is the most common lung tumor in children and adolescents. It is rarely seen in adults constituting 0.7% of adult lung tumor. Clinical manifestations are nonspecific. Up to 70% of patients are asymptomatic. Frequent symptoms may vary from cough, dyspnea, hemoptysis and weight loss.
Histologically, it is composed of fibrous tissues, myofibroblastic spindle cells and inflammatory cell proliferation. Although it usually show indolent clinical course, sarcomatous transformation has been described. And occasionally, it may show an aggressive behavior with local invasion and metastasis.
Radiologically, pulmonary IMT is frequently seen as a peripherally located solitary pulmonary nodule or mass. It may have lobulated contours and show varying degrees of heterogeneous enhancement on CT. It rarely manifest as a consolidative mass and cavitation may observed within a mass or consolidation. About 15% of IMTs show calcification. On PET, it usually shows high uptake indicating a high degree of metabolic activity.
Surgical resection is treatment of choice for accurate diagnosis and long term survival benefit. Chemotherapeutic agents may have little or no effect. In cases of tumor where ALK is positive on immunohistochemical staining, crizotinib can be used. Steroids and anti-inflammatory drugs have shown some benefit in cases where metastasis to bones and other distant organs.

Please refer to

Case 516, Case 790, Case 887,

KSTR Imaging Conference 2003 Summer  Case 9,

References

1. Furkan Ufuk et al. Inflammatory Myofibroblastic Tumor of the Lung: Unusual Imaging Findings of Three Cases, Pol J Radiol. 2015; 80: 479–482.
2. Nikolaos Panagiotopoulos et al. Inflammatory myofibroblastic tumour of the lung: a reactive lesion or a true neoplasm?, J Thorac Dis 2015;7(5):908-911
3. Youri Kaitoukov et al. Inflammatory pseudotumour of the lung, Can Respir J. 2011 Nov-Dec; 18(6): 315–317.

Keywords

lung, Inflammatory myofibroblastic tumor,