title: A case of pulmonary capillary hemangiomatosis with pulmonary fibrosis associated with MMP-9 related pulmonary remodeling.
abstract: Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension. It is characterized capillary proliferation within the alveolar septa. Here, we report a case of PCH with extensive pulmonary fibrosis. A 52-year-old man with a clinical diagnosis of non-specific interstitial pneumonia died of respiratory failure with severe pulmonary hypertension. Autopsy revealed pronounced right ventricle hypertrophy and pulmonary fibrosis. Consistent with clinical diagnosis, histological examination revealed diffuse pulmonary fibrosis, in addition, it also disclosed marked capillary proliferation within the alveolar septa as well as the fibrotic pulmonary stroma, suggesting the presence of PCH. Hemosiderin-laden macrophages had accumulated in the capillary proliferative area, and bronchiolar-type metaplasia was conspicuous in the fibrotic lesion. Proliferated capillaries were surrounded by fine collagen and α-smooth muscle actin-positive myofibroblasts. Immunohistochemistry revealed that type IV collagen around capillaries in the area of the PCH without inflammation disappeared in the area with inflammation. In addition, the PCH lesion contained significant numbers of macrophages expressing matrix metalloproteinase (MMP) 9 and type II pneumocytes positive for vascular endothelial growth factor. Although pulmonary fibrosis is a distinctive disease entity, different from PCH, MMP-9-driven destruction of the basement membrane may promote unusual pulmonary remodeling, which, in this case, resulted in extensive pulmonary fibrosis.
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Sakashita
authors.forename: Yashiro
authors.initials: Y
authors.lastname: Motooka
authors.forename: Masato
authors.initials: M
authors.lastname: Suganuma
authors.forename: Koji
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Takenobu
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ichiyasu
authors.forename: Motohiro
authors.initials: M
authors.lastname: Takeya
mesh_terms: D003937:Diagnosis, Differential; D004452:Echocardiography; D017809:Fatal Outcome; D018324:Hemangioma, Capillary / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000209:etiology*; D007150:Immunohistochemistry; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology; D008175:Lung Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D012131:Respiratory Insufficiency / Q000209:etiology; D014057:Tomography, X-Ray Computed
chemical_list: D020780:Matrix Metalloproteinase 9