Melioidosis mimicking primary lung malignancy with superior vena cava obstruction

A 59-year-old male Torres Strait Islander presented with reduced exercise tolerance, night sweats and weight loss of twenty kilograms. He was a recent ex-smoker with a forty-four pack year history and type II diabetes mellitus. Physical examination of his chest was unremarkable, but both internal jugular veins were engorged and non-pulsatile. Imaging demonstrated bulky mediastinal lymphadenopathy partially obstructing his superior vena cava (SVC) and causing partial collapse of the right upper lobe (Fig. 1A). The history, clinical findings and imaging were consistent with a diagnosis of SVC obstruction secondary to a lung malignancy. He was admitted to our hospital and commenced on high dose dexamethasone. In hospital, his glycemic control deteriorated and, although his blood pressure was 133/88 mmHg on admission, six days later this fell abruptly to 80/40 mmHg necessitating vasopressor support. Concurrent blood cultures grew Burkholderia pseudomallei and repeat imaging showed enlargement of the mediastinal adenopathy and the development of a gas-filled collection between the trachea and aorta (Fig. 1B). Intravenous meropenem was commenced and his condition improved. After three weeks the meropenem was changed to continuous intravenous ceftazidime infusion to permit outpatient management. After a total of four weeks of intravenous antimicrobials he received three months of oral trimethoprim/sulphamethoxazole with folic acid. Lymph node biopsy performed one month after his initial presentation revealed only reactive lymphoid material with no evidence of malignant cells. The mediastinal lymphadenopathy had resolved on imaging performed at completion of antimicrobial treatment (Fig. 1C).