Adding complexity to plexogenic arteriopathy.

In a landmark paper in the field of pulmonary hypertension research, Donald Heath and Jesse Edwards, in 1958, described the pulmonary vascular pathology that accompanies severe forms of pulmonary hypertension [1]. Examining lung tissue samples from patients with pulmonary hypertension associated with congenital heart disease and patients with primary pulmonary hypertension (now called idiopathic pulmonary arterial hypertension (PAH)), they distinguished six grades of severity and introduced the term “plexiform lesions”. Ever since, the plexiform lesions have been a subject of interest and of frequently contentious debates [2–5]. To touch on just a few of the unresolved issues and questions: why do these lesions form? How many of these lesions are present in a patient’s lung and are they haemodynamically important? What are the cellular components and the cell(s) of origin? A few investigators continue to be bored by these questions and have concluded that these complex vascular lesions are important mostly as an entertainment to a handful of pathologists.