Cavernous hemangioma, also called cavernous angioma, venous malformation, or cavernoma, is a type of venous malformation due to endothelial dysmorphogenesis from a lesion which is present at birth. A cavernoma in the brain is called a cerebral cavernous malformation or CCM. Despite its designation of a hemangioma, a cavernous hemangioma is not a tumor as it does not display endothelial hyperplasia. The abnormal tissue causes a slowing of blood flow through the cavities, or "caverns". The blood vessels do not form the necessary junctions with surrounding cells, and the structural support from the smooth muscle is hindered, causing leakage into the surrounding tissue. It is the leakage of blood, referred to as hemorrhage, that causes a variety of symptoms known to be associated with the condition. Symptoms
People with this condition in the brain may or may not experience symptoms. Some complications of the condition are life-threatening or cause major disruptions to normal functioning. Dangerous seizures due to compression of the brain, bleeding inside the brain tissue, vision problems, difficulty with speaking or using words, memory loss, ataxia, or hydrocephalus can occur. Less serious symptoms may include headaches and weakness or numbness in the arms or legs, though these symptoms alone do not indicate a person has the condition. In the eye, it may cause disruption or damage to the extraocular muscles and optic nerve which may manifest as double vision, progressive proptosis, decreased visual acuity, or other vision changes. It can lead to partial or complete blindness.
Tick-borne diseases like Rocky Mountain spotted fever produce a rash that may become extensive enough so as to be classified as exanthemous in as many as 90% of children with the disease. See also
List of cutaneous conditions

References
External links

Overview at About.com
Definition at MedTerms
Differential diagnosis
Dermatology Quiz Includes photo, diagnosis, and treatment of unilateral laterothoracic exanthem (ULE).