Ante-mortem diagnosis of pulmonary tumour thrombotic microangiopathy in a patient with unrecognised extramammary Paget's disease.

Pulmonary tumour thrombotic microangiopathy (PTTM) resulting in fatal pulmonary hypertension is a rare complication of malignancy. Patients with PTTM generally suffer rapid deterioration of hypoxaemia, and a diagnosis is often only made at autopsy. We report a case of extramammary Paget's disease associated with PTTM. An ante-mortem diagnosis was made based on cytology of blood aspirated from a pulmonary artery catheter in a wedged position. Together with a review of the literature, this case highlights the potential diagnostic value of blood cytology in patients with cancer with rapidly progressing pulmonary hypertension.