Inflammatory myofibroblastic tumor of the lung

Inflammatory
Myofibroblastic Tumour (IMT) of the lung. Sagittal image generated using MPR and averaging from original CT data
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Inflammatory
Myofibroblastic Tumour (IMT) of the lung. CT without contrast: sagittal view with the mediastinal window
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Inflammatory
Myofibroblastic Tumour (IMT) of the lung. CT with contrast: sagittal view
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Inflammatory
Myofibroblastic Tumour (IMT) of the lung. This figure demonstrates the heterogeneous enhancement of the lesion
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Inflammatory
Myofibroblastic Tumour (IMT) of the lung. CT without contrast: axial view with the lung window
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Inflammatory
myofibroblastic tumours: a pictorial review. PATHOLOGY: IMT of the lung. A 55-year-old man with a cough and haemoptysis.a Axial reformation of non-contrast CT with mediastinum window. Two solid, ill-defined nodules in right lower lobe are observed (yellow arrows). Note the air brocogram observed in the biggest mass. b Axial reformations with lung window of the same patient where the lung nodules are shown (white arrows). c Partial lobectomy of the right lower lobe specimen. Note the presence of the nodules (*). d Microscopic study of the resected lung sample where fusiform cells with an associated inflammatory infiltrate of lymphocytes, plasmatic cells and histiocytes was found
insightsimaging.springeropen.com • Open Access
Inflammatory
myofibroblastic tumour. Posteroanterior chest radiograph. Standard radiography shows a well-circumscribed nodule (arrow) in the right upper lobe.
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Inflammatory
myofibroblastic tumour. Axial image (mediastinal window). A well-circumscribed solid nodule (arrow) in the right upper lobe is confirmed. There is no contact with the chest wall. No other lesions were visualized.
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Inflammatory
myofibroblastic tumour. Axial image (lung window). A well-circumscribed solid nodule (arrow) in the right upper lobe is confirmed. There is no contact with the chest wall. No other lesions were visualized.
www.eurorad.org • CC by-nc-sa-4.0
Inflammatory
myofibroblastic tumour. Sagittal reformatted image (lung window). A well-circumscribed solid nodule (arrow) in the right upper lobe is confirmed. There is no contact with the chest wall. No other lesions were visualized.
www.eurorad.org • CC by-nc-sa-4.0
Inflammatory
myofibroblastic tumour. Axial image. Note an intensely FDG-avid solitary retrohilar nodule (arrow) within the right upper lobe.
www.eurorad.org • CC by-nc-sa-4.0
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Inflammatory myofibroblastic tumors of the lungs are a location-specific type of inflammatory myofibroblastic tumors.

Epidemiology

They are very rare with their incidence reported at approximately 0.04-1% of all the pulmonary neoplasms . While it can affect any age group, around 25% of cases occur in those under 18 years of age. It is the most common primary mass of the lung in children.

Pathology

It is generally considered to fall within the benign spectrum of tumors.

Microscopically they are characterized by abundant inflammatory infiltrate comprising of predominantly plasma cells, lymphocytes, histiocytes, admixed with a variable proportion of fibroblasts and myofibroblasts.

On immunohistochemistry, the tumor cells can exhibit

  • strong diffuse positivity with smooth muscle actin and vimentin
  • negativity for cytokeratin, CD34 and S100
Subtypes

They are sometimes divided into two subtypes:

  • non-invasive
  • invasive: usually occurs among younger patients and may reach large sizes

Radiographic features

CT

Typically seen as a single (can be multiple in ~5% of cases) peripheral, lobulated mass with lower lobe predominant occurrence. Calcification can occur (commoner in tumors occurring in children). Usually shows heterogeneous enhancement with contrast.

Nuclear medicine

Usually avid on FDG PET-CT.

Treatment and prognosis

Its behavior is often variable and the overall prognosis is often dependent on tumor size. Radical resection with negative margins is often the mainstay of treatment while radiation and steroids may be options in those who cannot undergo surgery. Long-term surveillance is often recommended due to local and distant recurrence as well as possible sarcomatous degeneration.

History and etymology

They were first observed in the lungs and described by Brunn in 1939.

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu entzündlicher Pseudotumor der Lunge:
pulmonales
Hamartom
Wikipedia • CC BY-SA 4.0
inflammatorischer
Pseudotumor
pediatricimaging.org • CC-by-nc-sa 4.0