The lower extremities often show atrophy and seldom show hypertrophy resulting in limb circumference discrepancy.When located on the trunk, the lesions of CMTC tend to show mosaic distribution in streaks with a sharp midline demarcation seen across the abdomen. The lesions are primarily localized, but can be segmental or generalized, often unilateral in appearance. Diffuse involvement of the skin is usually not observed. Although its course is variable, the majority of lesions in mild cases fade by adolescence. Ulceration and secondary infection are complications in severe cases and can be fatal if present in the neonatal period. Causes
Fewer than 100 cases of CMTC have been published worldwide. Petrozzi reported the first case of CMTC in the United States in 1970. CMTC is believed to be more common than suspected, as studies have shown that milder forms of the disease are not being recognized as CMTC.The pathophysiology is still unclear, with most cases occurring sporadically, although rare cases were reported in families. Studies indicated the primary involvement of capillaries, venules and veins, and possibly also that of arterioles and lymphatics. Hypotheses that have been proposed include: environmental/external factors; peripheral neural dysfunction; failure of the development of mesodermic vessels in an early embryonic stage; autosomal dominant inheritance with incomplete penetrance and, finally, the theory of Happle. Diagnosis
Differential diagnosis
During the first few weeks after birth, when the lesions are not very reticulated, CMTC may look very similar to vascular lesions such as port-wine stains. However, during follow-up, CMTC lesions become characteristic in their appearance.
Larger tumors may cause symptoms, depending on the size and location. Focal seizures may be caused by meningiomata that overlie the cerebrum. Progressive spastic weakness in legs and incontinence may be caused by tumors that overlie the parasagittal frontoparietal region. Tumors of the Sylvian aqueduct may cause myriad motor, sensory, aphasic, and seizure symptoms, depending on the location. Increased intracranial pressure eventually occurs, but is less frequent than in gliomas. Diplopia (Double vision) or uneven pupil size may be symptoms if related pressure causes a third and/or sixth nerve palsy. Causes
The causes of meningiomata are not well understood. Most cases are sporadic, appearing randomly, while some are familial. Persons who have undergone radiation, especially to the scalp, are more at risk for developing meningiomata, as are those who have had a brain injury. Atomic bomb survivors from Hiroshima had a higher than typical frequency of developing meningiomata, with the incidence increasing the closer that they were to the site of the explosion. Dental X-rays are correlated with an increased risk of meningioma, in particular for people who had frequent dental X-rays in the past, when the X-ray dose of a dental X-ray was higher than in the present.Having excess body fat increases the risk.A 2012 review found that mobile telephone use was unrelated to meningioma.People with neurofibromatosis type 2 (NF-2) have a 50% chance of developing one or more meningiomata.Ninety-two percent of meningiomata are benign. Eight percent are either atypical or malignant.