CVMs and haemangioma are both categorised as ‘vascular anomalies’, but the conditions are entirely different, so a precise understanding of their differences is essential for the proper diagnosis and management of these conditions.
Haemangioma (infantile/neonatal) is the most common tumour of infancy. It is a rapidly growing, but self-limiting vascular tumour that usually appears during the first 4 weeks of life. Explosive growth is common, and is generally triggered postnatally, but almost invariably undergoes spontaneous regression before the age 5–7 years. The rapid growth of haemangiomas is the result of endothelial proliferation with increased mitotic activity. In contrast CVMs are not hypercellular and have a ‘mature’ endothelium with normal endothelial mitotic activity, and grow pari passu with the child.2, 17, 18, 19 The differentiation of haemangioma and CVM is generally possible given the clinical history and the physical examination alone. However, a deeply seated haemangioma in subcutaneous tissue or muscle without involvement of the papillary dermis can be confusing, and occasionally needs histological confirmation. In addition to their differentiation from haemangiomas, CVMs2, 17, 18, 19 need to be differentiated from other vascular/non-vascular conditions involving soft tissue (e.g. haematoma, neurofibroma, and sarcoma). The proper differentiation of CVMs from various malignant tumours is critical in view of the potentially serious consequences when overlooked.20, 21, 22 If any doubt exists, a tissue biopsy should be obtained.