Pulmonary artery dissection in patients without underlying pulmonary hypertension

Pulmonary artery (PA) dissection is a rare event which usually occurs in patients with underlying pulmonary hypertension. We describe two patients who developed PA dissection without pre-existing pulmonary hypertension and present an extensive review of the literature.

In the first patient (a 59-year-old woman), acute-onset dyspnoea was initially thought to have been caused by pulmonary thrombosis, and thromboendarterectomy was performed. Histologically, pulmonary dissection without external rupture was evident, chiefly in the right main PA. In the second patient, an 85-year-old man who had hypergammaglobulinaemia of unknown cause and died from a haemorrhagic gastric ulcer, arterial dissection was detected at autopsy. There was no underlying pulmonary hypertension in either patient. Although the true reason for the development of dissection is unclear, pre-existing inflammation was considered to be related to its formation, at least in the second case.

A literature review indicated that idiopathic and inflammation-related PA dissection is extremely unusual. Since PA dissection is very rare, it is important to be aware of its features in order to make a correct diagnosis.