Angiosarcoma is a kind of normal tissue located in the skin, which is more distributed on the palm side of the hand, the plantar side of the foot and the fingers and toes, and its diameter is usually not more than 1 mm. Other parts of the body such as muscles, penis, trunk and internal organs such as stomach, nasal cavity and trachea can also occur. Most of them are solitary, and multiple occurrence is rare. It is more common in young and middle-aged people, and slightly more common in women than in men. The pathogenesis of angioglobuloma is still unclear, but trauma may be the cause, and local stimulation by long-term extrusion, friction and temperature change may also be related to its occurrence. Clinical manifestations Solitary hemangioblastoma often occurs in the fingers (toes), and is more common in females, typically in the nail bed. The tumor is small, usually 1 to 2 mm in diameter, rarely more than 3 mm. Blue or purple-red rice-like spots can be seen under the nail or under the skin, which are unusually sensitive. Patients are protected by their hands all day long to prevent painful attacks. If the affected limb is immersed in cold or hot water, the pain can be relieved, and some patients may also have symptoms of ipsilateral sympathetic vasomotor disorders, such as sweating and chilling of the affected limb and ipsilateral horner syndrome, when the pain attacks. In patients with long-standing subxiphoid hemangioblastoma, paraneoplastic bone loss can also be seen in the terminal phalanges. Multiple hemangioblastic tumors are less common and most often develop in childhood. They appear as large, soft blue nodules with extensive or limited damage and are mostly asymptomatic. Physical examination 1.Physical examination Large-headed needle pressure test (pain caused by the tail of a large-headed needle touching the surface of the tumor) is positive. Histopathology shows dilated vascular lumen lined with single layer of flattened endothelial cells, surrounded by several layers or multiple layers of vascular spheroid cells. There can be connective tissue, smooth muscle tissue and unmyelinated nerve fibers in the tumor. Electron microscopy reveals that the tumor cells have the characteristics of smooth muscle cells rather than epithelial cells. Immunohistochemistry is positive for Vimentin and basement membrane components. 3.Imaging X-ray examination is used to check whether the hemangioblastoma has compressed the finger bone and formed finger bone indentation, and to observe whether the hemangioblastoma has cyst-like changes of sclerosis. Magnetic resonance imaging can detect the lesion earlier, clearly show the boundary, locate accurately, and can clearly show its relationship with the surrounding tissues, which helps to determine the scope of the tumor in surgery. Diagnosis The diagnosis of finger (toe) damage with typical triad signs is easier. Pain in the finger (toe), especially severe pain produced by cold, local collision and pressure, should be firstly considered as angioblastoma of the finger. The diagnosis can be confirmed by a positive large-headed needle test and an X-ray indicating a tumor indentation on the dorsal side of the end phalanges. Angioblastoma outside the nail bed is difficult to diagnose and often misdiagnosed due to its small size, deep location, inaccurate localization and lack of the typical triad of angioblastoma signs. Differential diagnosis Subxiphoid hemangioblastoma should be distinguished from bone warts, fibroma, melanoma, etc. Outside the subxiphoid area, it should be distinguished from neurofibroma and hemangioma. Multiple hemangioblasts need to be distinguished from blue rubber nipple nevus syndrome (BRBNS). The differences between the two are: the latter is often congenital, whereas this disease often begins in childhood; BRBNS often involves the gastrointestinal tract, whereas this disease rarely involves the gastrointestinal tract; and histopathology shows characteristic hemangioblasts, whereas BRBNS has no hemangioblasts. Treatment Angioblastic tumors with pain should be surgically removed once diagnosed. Complete removal of the tumor is an effective treatment for this disease. Depending on the location of the tumor, a portion of the nail is excised and the nail bed is incised and retracted to reveal a small, round, intact pink or purplish-red tumor with clear margins located under the nail bed. It usually heals in about 2 weeks. Multiple hemangioblasts can be treated without special treatment if they are not painful. For those with significant pain, laser treatment can be used to reduce the pain, and if necessary, the painful lesions can be surgically removed.