Silent yet severe: inferior vena cava thrombosis associated with platypnoea–orthodeoxia. Is uterine sarcoma the culprit?

An elderly lady with a background of surgically treated uterine stromal sarcoma and deep venous thrombosis presented with exertional shortness of breath. On initial assessment, she was in type 1 respiratory failure and hypoxia was inconsistent with her symptoms and fluctuated with her position, demonstrating the features of platypnea-orthodeoxia. She was started on high flow nasal oxygen and treated as pulmonary embolism, although CT pulmonary angiography was normal. As there was a diagnostic dilemma, a repeat CT chest and abdomen was requested later which confirmed the presence of an extensive inferior vena cava thrombus extending from the right atrium to the left common iliac vein. She was managed conservatively following multidisciplinary discussions and succumbed to death later.Inferior vena cava thrombosis can rarely present with platypnea-orthodeoxia syndrome. This case highlights the importance of early recognition of symptoms with timely investigation and management to prevent life-threatening complications.