A Pediatric Radiology Textbook and Pediatric Radiology Digital Library
Pediatric Inflammatory Myofibroblastic Tumor
Etiology: Neoplasm of mesenchymal origin with intermediate biologic behavior
Imaging: — Solid, well defined, smooth or lobulated, minority are calcified — Primarily inflammatory or primarily fibrotic in appearance depending upon degree of inflammatory infiltrate versus stromal component and the stroma can be myxoid or fibrotic
Imaging in chest: Most commonly solitary mass (95%), can involve mediastinum and pleural space, can be endobronchial
Imaging PET FDG: Avid
Imaging MRI: — Inflammatory components: On T1WI are hypointense to muscle and on T2WI are hyperintense to muscle — Fibrotic components: On T1WI and T2WI are dark — T1WI post contrast: Heterogenous enhancement
DDX:
Complications:
Treatment:
Clinical: — Most common sites – lung or mesentery or omentum — Most common benign or low grade malignant lung mass in childhood
Radiology Cases of Inflammatory Myofibroblastic Tumor
CXR AP shows a round opacity laterally in the right lung (above left) which projects in the middle of the chest over the trachea on the lateral (above right). Axial CT without contrast of the chest (below) shows the opacity to be a solid mass without calcification next to the pleura.CXR AP and lateral (above) shows a well circumscribed, non-calcified, solid, round lesion in the right mid lung. AP image from a vintage tomogram (below) better demonstrates the lesion in the lung parenchyma.Coronal T1 MRI without (upper left) and with (upper right) contrast of the abdomen shows a large well circumscribed bi-lobed solid mass that enhances homogeneously in the abdomen and that along with the axial T2 image (below) is shown to not arise from any of the solid organs of the abdomen.Axial (left) and coronal (right) CT with contrast of the abdomen show a large, solid, heterogeneously enhancing mass in the left upper quadrant inferior to the stomach and spleen and anterior to the kidney whose organ of origin is uncertain.
Clinical Cases of Inflammatory Myofibroblastic Tumor
Clinical image shows a large firm abdominal mass causing abdominal distension.
Surgery Cases of Inflammatory Myofibroblastic Tumor
Surgical image shows a mass with a large number of collateral blood vessels that was intimately associated to the terminal ileum and cecum with the appendix draped across the mass.
Gross Pathology Cases of Inflammatory Myofibroblastic Tumor
Sectioned gross pathological image shows a tan to pink, firm, irregular solid mass measuring 14 x 13.5 x 8 cm. The mass was well encapsulated. No hemorrhagic necrosis or cystic degeneration was seen. Gross pathological image shows a pale solid mass in the center of the lung.
Histopathology Cases of Inflammatory Myofibroblastic Tumor
Histopathological image lower power H&E stained section shows the intimate relationship of the lesion to the small intestine (upper right).Histopathological image higher power H&E stained section shows a vaguely fascicular proliferation of bland, spindle-shaped cells, an occasional mitosis and numerous inflammatory cells. The latter include primarily lymphocytes and plasma cells.
