Lung tumor
Benign tumors
Pulmonary capillary hemangiomatosis (PCH)

Author: Roseann I. Wu, M.D. (see Authors page)

Revised: 22 April 2016, last major update April 2016

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Pulmonary capillary hemangiomatosis
Cite this page: Pulmonary capillary hemangiomatosis. website. Accessed October 21st, 2016.
Definition / General
  • Proliferation of benign appearing capillaries in alveolar septa that appear to compress pulmonary veins
  • May represent a secondary angioproliferative process of veno-occlusive disease caused by postcapillary obstruction rather than a distinct entity (Am J Surg Pathol 2006;30:850)
  • Poor prognosis, median survival after symptom onset is 3 years
Essential Features
  • Disordered proliferation of capillaries within interstitial tissue, including involvement of larger pulmonary vessel walls and airways
  • Closely related to pulmonary veno-occlusive disease (PVOD) and could be secondary process, manifests as pulmonary hypertension
  • CD31 and CD34 immunohistochemistry can help distinguish capillary proliferation from congestion
  • Controversial whether a distinct entity from pulmonary veno-occlusive disease (PVOD)
  • Consider diagnosis of "secondary PCH" or PCH-like changes for proliferations seen in association with other disorders, reserving "primary PCH" for extremely rare cases without recognizable causative background disease (Am J Surg Pathol 2006;30:850)
  • Very rare, mostly in adults
  • Mean age 30 years, range 2-71 years
  • Chronic passive congestion may lead to capillary proliferation
  • Not known; thought to be neoplastic but not entirely clear
Clinical Features
  • Clinically mimics PVOD or atypical interstitial lung disease due to presence of pulmonary hypertension
  • Nonspecific symptoms: progressive dyspnea, cough, chest pain, fatigue, small amount of hemoptysis
  • Pulmonary function tests show normal FVC and FEV with reduced diffusion capacity
  • Clinically and radiographically indistinguishable from PVOD; diagnosis requires microscopic diagnosis by lung biopsy
  • Diagnosis frequently made on explant specimen or after death
Radiology Description
  • Findings seen in pulmonary hypertension; i.e. cardiomegaly, enlarged pulmonary arteries
  • Chest Xray: interstitial infiltrates, thick interlobular septa, bibasilar reticulonodular or micronodular areas of opacity, lymphoadenopathy
  • HRCT: diffuse centrilobular ground glass opacity (Cardiovasc Pathol 2013;22:287), peripheral sparing
Prognostic Factors
  • Prostacyclin therapy (used in pulmonary hypertension) may cause sudden respiratory distress and death in these patients
Case Reports
  • Lung transplantation is only definitive treatment but recurrence has been reported
  • Drugs for other causes of pulmonary hypertension are relatively ineffective
  • Case reports suggest Interferon α-2a or doxycycline may be effective
Clinical Images

Images hosted on other servers:

Category 1 pulmonary hypertension diagnosed postmortem
as secondary to pulmonary capillary hemangiomatosis (PCH)

Category 1 pulmonary hypertension due to a
second case of pulmonary capillary hemangiomatosis

Gross Description
  • Multiple, red-brown, ill defined, nodular lesions
  • Congested, edematous, without significant fibrosis
Gross Images

Left lung with pulmonary parenchyma

Micro Description
  • Preserved architecture with areas of involvement admixed with areas of normal lung
  • Proliferation of benign appearing capillaries expanding alveolar septa that appear to compress pulmonary veins
  • Proliferation around bronchovascular bundles creating nodular appearance
  • At least 2 layers of aberrant capillaries within alveolar wall (Arch Pathol Lab Med 2015;139:274)
  • Bland endothelial cells, no mitoses
  • Intra-alveolar hemosiderin-laden macrophages, small areas of acute or old hemorrhage, hemosiderosis
  • Small pulmonary arteries with intimal thickening/medial hypertrophy
Micro Images

Images hosted on other servers:

(A)small veins demonstrate marked myointimal thickening; adjacent alveolar septa are
thickened by endothelial cell proliferation of pulmonary capillary hemangiomatosis;
(B) CD31 highlights endothelial cell proliferation

Pulmonary capillary hemangiomatosis

Images hosted on Flickr:

Various images

Cytology Description
  • Alveolar lavage often with increased hemosiderin-laden macrophages
Positive Stains
Molecular / Cytogenetics Description
Differential Diagnosis
  • Capillary congestion
  • Veno-occlusive disease: associated with PCH; eccentric intimal thickening of venules in lobular septa with some septal veins completely occluded, increased elastic fibers in venous media (highlighted with elastin stain); intimal fibrosis narrows and occludes the pulmonary veins, causing dilatation of capillaries