Right brachiocephalic cavernous hemangioma: a rare vascular mimic of a superior mediastinal mass

Cavernous hemangiomas of the mediastinum are rare vascular malformations that can mimic neoplasms on imaging. Their imaging features often overlap with those of malignant superior mediastinal masses, presenting a diagnostic challenge. We present the case of a 35-year-old male in whom a right superior mediastinal mass was incidentally detected during preoperative evaluation. Imaging revealed a well-defined lesion involving the right brachiocephalic vein, internal jugular vein, and superior vena cava. Due to initial concern for malignancy, an open surgical biopsy was performed, which confirmed the diagnosis of a cavernous hemangioma. The procedure was complicated by profuse intraoperative bleeding and a large postoperative hematoma. Given the lesion’s benign nature and surgical risks, conservative management with imaging surveillance was adopted. This case highlights the diagnostic challenge of mediastinal vascular lesions and reinforces the value of multiphasic contrast-enhanced imaging in differentiating them from malignancies. Early identification of vascular characteristics can help avoid unnecessary invasive procedures and guide appropriate patient care.