What is the diagnosis for Pulmonary Veno-Occlusive Disease (PVOD) / Pulmonary Capillary Hemangiomatosis (PCH)?

From the Guidelines

Pulmonary Veno-Occlusive Disease (PVOD) and Pulmonary Capillary Hemangiomatosis (PCH) are diagnosed through a comprehensive approach combining clinical evaluation, imaging, and sometimes lung biopsy, with high-resolution CT scanning being the cornerstone of non-invasive diagnosis, as suggested by the most recent and highest quality study 1. The diagnosis of PVOD and PCH should be suspected in patients presenting with unexplained pulmonary hypertension, especially those with risk factors like chemotherapy exposure or genetic predisposition.

• Key clinical features include:
  • Dyspnea on exertion and fatigue
  • Digital clubbing and bi-basal crackles on lung auscultation
  • Severe hypoxemia and low diffusion capacity of carbon monoxide
• Imaging findings on high-resolution CT scanning typically show:
  • Centrilobular ground-glass opacities
  • Septal thickening
  • Lymphadenopathy
• Pulmonary function tests often reveal decreased diffusion capacity and normal spirometry, as noted in 1 and 1.
• Right heart catheterization demonstrates pre-capillary pulmonary hypertension with elevated pulmonary arterial pressure and normal wedge pressure.
• Genetic testing for EIF2AK4 mutations can confirm the diagnosis in familial cases.
• Lung biopsy, though risky, provides definitive diagnosis by showing venular fibrosis, capillary proliferation, and hemosiderin-laden macrophages, as highlighted in 1.
• Caution is warranted when using pulmonary vasodilators as they can precipitate pulmonary edema in PVOD/PCH patients.
• Early referral for lung transplantation evaluation is essential as this represents the only definitive treatment for this progressive and often fatal condition, as emphasized in 1.

From the Research

Diagnosis of Pulmonary Veno-Occlusive Disease (PVOD) / Pulmonary Capillary Hemangiomatosis (PCH)

The diagnosis of PVOD/PCH can be challenging, but several clinical, functional, and hemodynamic characteristics can help identify these patients.

• A definite diagnosis of PVOD requires a lung biopsy or pathologic examination of pulmonary explants or postmortem lung samples 2.
• However, lung biopsy is hazardous in patients with severe pulmonary hypertension, and noninvasive diagnostic tools are needed 2.
• High-resolution computed tomography (HRCT) of the chest can suggest PVOD/PCH in the setting of pulmonary hypertension when it shows:
  • Nodular ground-glass opacities
  • Septal lines
  • Lymph node enlargement
  • Pleural effusion 2, 3, 4, 5, 6
• Occult alveolar hemorrhage found on bronchoalveolar lavage in patients with pulmonary hypertension is associated with PVOD/PCH 2, 3, 4, 5.
• Clinical presentation of PVOD/PCH is similar to idiopathic pulmonary arterial hypertension (IPAH), but with some differences:
  • Higher male:female ratio
  • Higher tobacco exposure
  • Lower arterial oxygen tension at rest
  • Lower diffusing capacity of the lung for carbon monoxide
  • Lower oxygen saturation nadir during the 6-minute walk test 2, 3, 4
• A noninvasive diagnostic approach using HRCT of the chest, arterial blood gases, pulmonary function tests, and bronchoalveolar lavage can be helpful for detecting PVOD/PCH patients and avoiding high-risk surgical lung biopsy for histological confirmation 3, 4, 5.
• Gene testing can also be helpful in diagnosing PVOD/PCH and avoiding the risk of surgical biopsy 6.