A 41-year-old Caucasian woman presented to the emergency department with four day history of intermittent non-specific chest pain on a background of 30 pack years of smoking history. She also had a history of progressive exertional dyspnea for a few months and also loss of appetite during this presentation. She denied fever, cough, hemoptysis, pleurisy or coryzal symptoms. She had no significant past medical history, in particular, there was no history of diabetes and she was not on any regular medications. She had no significant occupational or travel history of significance. There was no history of exposure to tuberculosis. She was an avid gardener, residing in Darwin, Northern Territory of Australia. She usually walked barefoot in her garden and used large amounts of potting mix while gardening. She denied excessive alcohol consumption or recreational drug usage.
On clinical examination, vital signs were normal. Respiratory examination was unremarkable, with normal breath sounds bilaterally and there were no crackles or rhonchi or pleural rub in particular. Cardiovascular examination was also normal. Systemic examination showed no evidence of clubbing, oedema, cyanosis or lymphadenopathy. Her ECG showed normal sinus rhythm without ischemic changes. Blood tests showed white cell count of 11.5 x 109/L with neutrophilia 7.9 x 109/L and CRP was 15 Mg/L, Serial troponins were negative. Liver function, electrolytes, renal function were within normal limits. Quantiferon gold test was negative. Pulmonary function showed FVC of 3.88 L, (97% predicted), FEV1 3.05 L (92% predicted), FEV1/FVC ratio 0.787 (96% predicted), DLCO 77% and TLC 4.75L (89% predicted). Chest X-ray showed an opacity in the right mid-zone (Fig. 1a). She underwent a CT scan of the chest, that showed a mass in the right lower lobe measuring approximately 36 x 22mm suspicious of malignancy. There was no endoluminal bronchial lesion nor mediastinal or hilar lymph node enlargement. (Fig. 1b). Due to the high index of suspicion of lung malignancy, a PET-CT was performed, which demonstrated mild to moderate FDG avidity of the mass in the right lower lobe (Fig. 2a) but no other FDG avid nodal or distant metastatic disease. The patient underwent flexible bronchoscopy that showed no endobronchial lesion, then using the Endobrochial radial Ultrasound (EBUS) probe and utilizing the Guide sheath technique, the lesion was localized in the posterior segment of the right lower lobe. The EBUS images (Fig. 2b) demonstrated a heterogeneous lesion with non-compressed blood vessels and scattered air space shadows. Brushings, biopsies and washings were taken from the guide sheath, along with a transbronchial cryobiopsy from the same site identified by the ultrasound probe. The EBUS-guided biopsy of the lesion showed necrotic tissues and malignant cells were not identified. Culture of bronchial brushings on Ashdown's agar medium, however, grew bacterial colonies which were identified microscopically as gram negative bacilli. Bacterial culture from bronchial brushings was subsequently confirmed as Burkholderia pseudomallei, making the diagnosis of pulmonary melioidosis (Fig. 3). She was treated with intravenous ceftazidime 2 g 6 hourly for 4 weeks, followed by oral sulphamethoxazole/trimethoprim (800mg/160mg) 2 tablets twice a day for 3 months with daily folic acid 5mg. During the follow up visits, the patient demonstrated significant improvement both clinically and radiologically. Her CRP was noted to be < 0.1 Mg/L consistently, with normal white cell and neutrophil counts. Her exertional dyspnea was considered to be related to early airway disease secondary to smoking, possibly aggravated in the presence of pulmonary melioidosis and she was provided with support for smoking cessation.
PET CT - FDG avidity shown in right lower lobe mass.