Pulmonary tumour thrombotic microangiopathy (PTTM) presents as acute pulmonary hypertension and sudden cardiovascular collapse in individuals with adenocarcinoma, usually of the stomach. The illness follows a fulminant course often before the adenocarcinoma has become clinically apparent. Frequently the diagnosis is made only at necropsy. The diagnosis can be made by pulmonary microvascular cytology, obtained through a wedged pulmonary artery catheter. No treatment has thus far been found to be of benefit. We present a typical case in which the diagnosis was not reached before death despite multiple investigations and review the literature.