An Unusual Cause of Transient Ischemic Attack

1Department of Cardiology, Royal Melbourne Hospital; 2Institute for Breathing and Sleep, Heidelberg; 3Department of Respiratory and Sleep Medicine, Royal Melbourne Hospital, Melbourne, Victoria, Australia Correspondence: Dr Liam Hannan, Institute for Breathing and Sleep, 145 Studley Road, Heidelberg, Melbourne, Victoria 3084, Australia. Telephone 778-8361863, e-mail liam.hannan@austin.org.au In April 2011, a 57-year-old woman with a long smoking history presented with transient symptoms of left-hand incoordination and dysarthria. At the time of arrival to hospital, there had been complete resolution of neurological signs and symptoms. Computed tomography and subsequent magnetic resonance imaging of the brain demonstrated no evidence of cerebral infarction and no other intracranial pathology. A routine chest radiograph revealed right middle lobe collapse. Computed tomography of the chest demonstrated a large proximal obstructing mass within the right middle lobe in addition to multiple bilateral pulmonary nodules suggestive of an advanced primary bronchogenic carcinoma with pulmonary metastases. There appeared to be tumour extension into the lateral wall of the left atrium (Figures 1A and 1B). Standard bronchoscopy demonstrated an endobronchial tumour at the origin of the right middle lobe bronchus, and endobronchial biopsy and brush cytology confirmed an adenocarcinoma that was TTF-1 and cytokeratin positive, consistent with a primary lung malignancy. A transesophageal echocardiogram demonstrated tumour infiltration of the right lower pulmonary vein with extension into the left atrium (Figure 2). There was no evidence of vegetations on the aortic or mitral valves, effectively excluding the possibility of marantic endocarditis. No other alternative sources of emboli were identified to explain the transient ischemic attack. With the exception of atrial myxoma, embolic phenomena due to intracardiac tumours are uncommon. Previous case reports of intracardiac extension of primary lung tumours have generally described extension via the pulmonary vein, as was apparent in the present case (1). The patient was referred for palliative radiotherapy for the primary lesion in addition to systemic chemotherapy. imAges in RespiRAtoRy medicine