Pulmonary capillary hemangiomatosis: an immunohistochemical analysis of vascular remodeling.

Unlabelled: QUESTION OF STUDY: Pulmonary capillary hemangiomatosis (PCH) is an extremely rare cause of severe pulmonary hypertension. It is characterized histologically by exuberant proliferation of capillaries that often invade alveolar septae, bronchial walls, and pleura. Expression of vascular remodeling markers in PCH is not known.

Materials/patients And Methods: Using antibodies directed against vascular remodeling markers known to be abnormally expressed in plexiform lesions of idiopathic pulmonary hypertension, we performed the first detailed immunohistochemical analysis of the lungs in a patient with PCH. -

Results: As in plexiform lesions, the PCH lesions have increased expression of markers associated with cellular proliferation and angiogenesis such as vascular endothelial growth factor and MiB-1. In contrast to plexiform lesions, the PCH lesions retain markers of cell growth suppression such as peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and caveolin-1.

Answer To Question: This study suggests that the aberrant endothelial cells that lead to the characteristic lesions of PCH and idiopathic pulmonary hypertension are distinct.