An Unusual Pulmonary Embolus

Mrs. L., a 51 year old housewife, presented with a 2 cm. lump in the left breast, which she had first noticed three months previously. Excision biopsy revealed a very poorly differentiated adenocarcinoma with tumour in adjacent vessels. When radiotherapy was instituted 3 weeks later she complained of shortness of breath on exercise, and a dry cough. Over the following week she became increasingly dyspnoeic, tachypnoeic and cyanosed. Investigations included a chest radiograph, which was normal, and an isotope ventilation/perfusion scan, part of which is reproduced below (Figure 1). This shows multiple small perfusion defects in the right mid and upper zones without corresponding defects in ventilation, indicating pulmonary emboli. Anticoagulant therapy was started, but the patient deteriorated and died a week later.