Coexistent hereditary haemorrhagic telangiectasia and primary thrombocythaemia--coincidence or syndrome?

Two patients with coexistent hereditary haemorrhagic telangiectasia (HHT) and primary thrombocythaemia (PT) are presented. In one of them, both diseases were detected at the same time. In the other, signs of HHT were present 20 years prior to the diagnosis of PT. Both patients had recurrent gastrointestinal haemorrhage with consequent anaemia, and multiple gastric telangiectases were demonstrated endoscopically. Persistent and severe haemorrhage from gastric telangiectases in one of the patients was successfully controlled by endoscopic monopolar electrocoagulation. The very high platelet counts were reduced with melphalan in one patient and with busulfan in the other. The degree of severity of both disorders was parallel in both cases. We suggest that the coexistence of these two rare disorders in one and the same patient may represent a syndrome that could be more common than hitherto known.