New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.
A vascular anomaly due to proliferation of BLOOD VESSELS that forms a tumor-like mass. The common types involve CAPILLARIES and VEINS. It can occur anywhere in the body but is most frequently noticed in the SKIN and SUBCUTANEOUS TISSUE. (from Stedman, 27th ed, 2000)