Lung tumor
Pulmonary capillary hemangiomatosis

Topic Completed: 1 April 2016

Minor changes: 23 October 2019

Copyright: 2003-2019,, Inc.

PubMed Search: Pulmonary capillary hemangiomatosis

Roseann Wu, M.D., M.P.H.
Page views in 2019: 930
Page views in 2020 to date: 466
Cite this page: Wu R. Pulmonary capillary hemangiomatosis. website. Accessed August 8th, 2020.
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

Microscopic (histologic) 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
Microscopic (histologic) 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
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