Superior vena cava obstruction: dangers of a missed diagnosis

We report the case of a 7 year old girl who presented to the Children's Emergency Department with a 6 week history of bilateral facial and neck swelling. She had felt generally unwell, tired, with a recent onset of dry cough, and had presented multiple times to her general practitioner (GP) who after initially unsuccessfully trying an antihistamine, had given her five courses of soluble Betamethasone (corticosteroid) over six weeks, for presumed allergy; this temporarily relieved her symptoms for a couple of days each time. On subsequent referral to Accident and Emergency she was found to have a superior mediastinal mass, with a left pleural effusion and mediastinal deviation to the right. Further investigation confirmed the diagnosis of a T-cell lymphoma causing superior vena cava obstruction of blood flow through the SVC to the right atrium and is a classical oncological emergency. This case report highlights the importance of recognizing superior vena cava obstruction and the need for awareness of malignancy as a differential diagnosis when initially presented with a child with non-specific respiratory findings. We highlight that acute tumour lysis syndrome, a life threatening metabolic emergency that results from massive cytolysis of malignant cells, may occur after a single dose of corticosteroids and one should be aware of this potentially life-threatening complication.