Pulmonary capillary hemangiomatosis

Pulmonary Capillary Hemangiomatosis (PCH) is a rare and serious lung disease characterized by the proliferation of capillaries within the lungs. This condition leads to the thickening of the alveolar septa and the pre-capillary arterioles, causing significant respiratory distress and, if left untreated, can result in heart failure due to the increased pressure on the heart's right ventricle.

Etiology

The exact cause of Pulmonary Capillary Hemangiomatosis is currently unknown. However, it is believed to be sporadic, with no clear genetic predisposition identified. Some studies suggest a possible link to mutations in the EIF2AK4 gene, which have also been associated with Pulmonary veno-occlusive disease (PVOD), indicating a potential genetic overlap between PCH and PVOD.

Pathophysiology

PCH is characterized by the uncontrolled proliferation of capillary blood vessels within the lung's interstitial and alveolar spaces. This proliferation leads to the obstruction of pulmonary blood flow, increased pulmonary vascular resistance, and eventually, pulmonary hypertension. The increased pressure in the pulmonary circulation places a significant burden on the right ventricle of the heart, leading to right-sided heart failure if untreated.

Clinical Presentation

Patients with Pulmonary Capillary Hemangiomatosis typically present with symptoms of progressive dyspnea (difficulty breathing), fatigue, and signs of right-sided heart failure such as edema (swelling) and ascites (abdominal fluid accumulation). Other symptoms may include hemoptysis (coughing up blood) and chest pain.

Diagnosis

Diagnosing PCH is challenging due to its rarity and the nonspecific nature of its symptoms, which can mimic other forms of pulmonary hypertension. A definitive diagnosis usually requires a lung biopsy, which shows the characteristic capillary proliferation. Other diagnostic tools include High-resolution computed tomography (HRCT) of the chest, echocardiography to assess heart function, and pulmonary function tests.

Treatment

Treatment of Pulmonary Capillary Hemangiomatosis is complex and often focuses on managing symptoms and slowing the progression of the disease. Therapeutic strategies may include oxygen therapy, anticoagulants to prevent blood clots, and medications to manage pulmonary hypertension. In severe cases, lung transplantation may be considered the only definitive treatment option.

Prognosis

The prognosis for patients with PCH is generally poor, with a median survival time of approximately 3 years from diagnosis without lung transplantation. Early diagnosis and management of pulmonary hypertension can improve outcomes, but the progressive nature of the disease often leads to fatal outcomes.

Epidemiology

Pulmonary Capillary Hemangiomatosis is an extremely rare condition, with only a few hundred cases reported in the medical literature worldwide. It can affect individuals of any age but is most commonly diagnosed in young adults.

NIH genetic and rare disease info

• NIH info on Pulmonary capillary hemangiomatosis

Pulmonary capillary hemangiomatosis is a rare disease.