BACKGROUND: Mediastinal vascular malformations are rare, and most patients are asymptomatic or present with unrelated symptoms. Imaging can be challenging to interpret, but plays an important role in diagnosis and prognostication.

CASE REPORT: We present the case of a 48-year-old man with history of intravenous drug abuse and incompletely treated pulmonary tuberculosis. A computed tomography (CT) scan done for respiratory symptoms showed an extensive soft-tissue mass in the mediastinum and upper abdomen, initially thought to represent tuberculous adenitis with possible esophageal involvement, which appeared variceal in nature on endoscopy. Further investigation with open mediastinal biopsy and magnetic resonance imaging (MRI) eventually led to the diagnosis of a low-flow venous mediastinal vascular malformation. The patient responded well to conservative management, with the malformation remaining stable on follow-up CT up to a decade later.

CONCLUSIONS: Radiologists should be aware of the rare but important differential diagnosis of a vascular malformation, particularly when an extensive infiltrative calcified mediastinal soft-tissue mass is encountered. Multi-modality imaging, particularly MRI, which can demonstrate typical features, is crucial for diagnosis and prognostication, thereby avoiding unnecessary invasive procedures and treatment.

Keywords: Esophageal and Gastric Varices, Mediastinum, Radiology, Tuberculosis, vascular malformations, Diagnosis, Differential