Superior Vena Cava Syndrome Mimicking an Allergic Angioedema: A Diagnostic Odyssey from Allergic Reaction to Mediastinal B-Cell Lymphoma.

An 18-year-old woman presented to her general practitioner with a history of non-itching facial swelling, erythematous skin rash and a slightly coarse voice for a few days. She denied dyspnoea, B-symptoms and pain. Physical examination revealed generalized facial and neck swelling not involving the tongue or the oral mucous membranes. There was no lymphadenopathy. These findings resulted in the diagnosis of allergic angioedema and in oral treatment with corticosteroids and antihistamines. The swelling responded partially but reoccurred with dose reduction of the corticosteroids. Outpatient referrals to a dermatologist, an endocrinologist and a rheumatologist resulted in confirmation of the diagnosis of allergic angioedema, suspected iatrogenic Cushing syndrome and possible connective tissue disease, respectively. Three months after the first outpatient presentation the patient was admitted to our hospital with severe fatigue and left-sided chest pain. The clinical examination showed the known facial and neck swelling- and a sinus tachycardia (120 bpm) without any fever. Furthermore, the neck swelling seemed to be slightly asymmetrical. This was accompanied by leucocytosis, elevated C-reactive protein, and lactate dehydrogenase. An electrocardiogram showed sinus tachycardia (120/min) with a S1Q3-type. An ultrasound of the neck showed thrombosis of the left jugular vein. Subsequent computed tomography scan of the chest revealed a large mediastinal mass causing acute superior vena cava syndrome. Mediastinal large B-cell lymphoma was confirmed by biopsy. The patient underwent six cycles of DA-R-EPOCH (rituximab, etoposide, prednisolone, vincristine, cyclophosphamide, doxorubicin). Treatment resulted in complete response. LEARNING POINTS: Vena cava superior syndrome is caused in over 60% of the cases by malignancies (bronchogenic carcinoma, lymphoma, germ cell tumour).Facial swelling, plethora of the upper chest without itchiness and hoarseness are classical symptoms of thoracic central venous obstruction.At every patient visit open-minded clinical reasoning should be used to avoid anchoring bias.