From the Guidelines
Pulmonary hemangiomas are rare benign vascular tumors of the lung that can be classified into several types, including cavernous hemangiomas, capillary hemangiomas, and arteriovenous hemangiomas. The main types of pulmonary hemangiomas are:
- Cavernous hemangiomas, which are the most common and consist of large dilated blood vessels
- Capillary hemangiomas, which are composed of small capillary-sized vessels
- Arteriovenous hemangiomas, which involve direct connections between arteries and veins Other less common variants include sclerosing hemangiomas (now called pneumocytomas), which have a mixed cell population and are not true vascular tumors despite their name, and epithelioid hemangiomas, which have distinctive epithelioid endothelial cells 1. These lesions are typically asymptomatic and found incidentally on imaging, though larger ones may cause symptoms like hemoptysis, cough, or chest pain. Management depends on the size, location, and symptoms, ranging from observation for small asymptomatic lesions to surgical resection for larger or symptomatic ones. Pulmonary hemangiomas develop from abnormal proliferation of blood vessels in lung tissue, though the exact cause remains unclear. They are distinguished from malignant vascular tumors like angiosarcomas by their well-circumscribed borders and lack of cellular atypia. It's worth noting that the provided evidence primarily discusses pulmonary arteriovenous malformations (PAVMs) rather than pulmonary hemangiomas, but the information on vascular tumors and malformations can still be relevant 1. However, for the most recent and highest quality information on pulmonary hemangiomas, further research would be necessary.
From the Research
Types of Pulmonary Hemangiomas
- Cavernous hemangiomas: benign vascular tumors that can occur in the lungs, characterized by dilated vascular spaces lined by flattened bland cells 2, 3, 4
- Pulmonary capillary hemangiomatosis: a rare and locally aggressive benign vascular neoplasm of the lung, characterized by the presence of numerous cytologically benign thin-walled capillary-sized blood vessels proliferating diffusely through the pulmonary interstitium 5, 6
Characteristics of Pulmonary Hemangiomas
- Cavernous hemangiomas: mostly asymptomatic, but can cause respiratory distress, cardiac failure, and massive haemoptysis 2
- Pulmonary capillary hemangiomatosis: characterized by pulmonary hypertension and a slowly progressive clinical course, often misdiagnosed as primary pulmonary hypertension or veno-occlusive disease 5, 6
Diagnosis and Treatment of Pulmonary Hemangiomas
- Definitive diagnosis of pulmonary hemangiomas can only be made by histopathological and immunohistochemical examination 2, 3, 4
- Treatment options for pulmonary hemangiomas include surgical excision, with lung transplant being the only definitive treatment for pulmonary capillary hemangiomatosis 5, 4, 6