Intravenous leiomyomatosis manifesting as saddle embolism

A 51-year-old, otherwise well woman, presented with progressive severe dyspnoea. CT pulmonary angiogram (CTPA) demonstrated a large filling defect within the right main pulmonary artery with evidence of right heart strain. She was anticoagulated and discharged home; however, was readmitted with progression of symptoms and hypotension within 1 month. Repeat CTPA demonstrated progression of the filling defect. Formal surgical thrombectomy was performed with removal of an unusual cream-coloured, rubber-like material. Histological analysis revealed intravenous leiomyomatosis (IVL). IVL is a rare benign neoplasm, characterised by smooth muscle cell proliferation in vascular structures that can act aggressively. This case describes the workup, recognition and management of IVL.