Intravascular organizing thrombus in the forearm: a unique imaging presentation.

Area of Science:

• Vascular Pathology
• Radiology
• Histopathology

Background:

• Organizing thrombus is a common finding in healing thrombi, but rarely large enough for imaging.
• Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is an exuberant form of organizing thrombus that can mimic malignancy.
• Distinguishing IPEH from other intravascular masses requires histopathological analysis.

Purpose of the Study:

• To report a case of a large, organizing thrombus presenting as an intravascular mass in the forearm.
• To discuss the imaging and histopathological findings in differentiating benign organizing thrombus from other intravascular lesions.
• To highlight conservative management for such benign conditions.

Main Methods:

• Case report of a patient with forearm swelling and a history of basilic vein thrombus.
• Diagnostic imaging including ultrasound and MRI to characterize the intravascular mass.
• Percutaneous biopsy for histopathological examination.

Main Results:

• Ultrasound revealed a heterogeneous, noncompressible intravascular mass with internal vascularity.
• MRI demonstrated an enhancing mass in the left basilic vein, with differentials including IPEH and neoplasm.
• Histopathology showed reactive vascular proliferation and organizing thrombus, but lacked the characteristic papillary architecture of IPEH.

Conclusions:

• Exuberant organizing thrombus can present as a significant enhancing intravascular mass, mimicking neoplastic processes.
• While IPEH is a consideration, other forms of reactive vascular proliferation and organizing thrombus are also possible.
• Conservative management may be appropriate for benign organizing thrombus presenting as an intravascular mass, avoiding unnecessary surgical intervention.