IntroductionAcute pulmonary embolism has varied presentations ranging from asymptomatic, incidentally discovered emboli to massive embolism, causing immediate death. Tumor embolism is a rare but unique complication of malignancies. This uncommon catastrophe of a malignant tumor in a young patient, culminating as a pulmonary embolism, is being reported for the first time.Case presentationA 19-year-old Asian man presented to the emergency service at our hospital with acute onset dyspnea. His clinical examination led to the suspicion of an acute pulmonary embolism with a lower lumbosacral radiculopathy. A magnetic resonance imaging scan of the pelvis demonstrated a chondrosarcoma arising from the right iliac wing, eroding into the common iliac vein and creeping up the inferior vena cava to lodge in the pulmonary artery, thus producing a saddle embolus.ConclusionThe importance of exploring for malignancies in the event of an idiopathic pulmonary embolism is highlighted. Early detection of such malignancies can substantially affect the outcome in young patients.