Inflammatory myofibroblastic tumor of the bladder: Computed tomographic features

Area of Science:

• Radiology
• Oncology
• Pathology

Background:

• Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with intermediate biologic potential.
• Lack of understanding of IMT often complicates preoperative diagnosis and treatment planning.

Purpose of the Study:

• To characterize the computed tomography (CT) features of bladder inflammatory myofibroblastic tumors (IMT).
• To improve preoperative diagnosis and treatment strategies for bladder IMT.

Main Methods:

• Retrospective review of CT images from nine pathologically confirmed bladder IMT cases.
• Assessment of lesion characteristics including diameter, location, contour, growth pattern, margin, boundary, density, and enhancement patterns on unenhanced and contrast-enhanced CT scans.

Main Results:

• Most bladder IMTs presented as single polypoid nodules (89%), often with an endophytic growth pattern (44%).
• Characteristic CT findings included ring-shaped or heterogeneous enhancement (33% and 66%, respectively) and symmetrical central changes post-enhancement.
• Tumor margins were mostly smooth (89%), and boundaries were typically clear (78%).

Conclusions:

• Bladder IMT typically manifests as a single, superiorly located, polypoid nodule with endophytic growth.
• Ring-shaped enhancement and symmetrical post-enhancement changes are characteristic CT findings for bladder IMT.
• CT imaging can provide valuable insights for the preoperative diagnosis of bladder IMT.