IMPORTANCE Heterotopic glial tissue is a rare, benign congenital anomaly that can present as a fibrous mass with or without overt signs of neural tissue origin, such as overlying alopecia, pigmentation, or a "hair collar" sign. These lesions are typically found in the midline area, though they have been found laterally involving the mastoid and middle ear regions. As demonstrated by this case r...

Albrecht introduced the concept of hamartoma at beginning twentieth century to designate a tumor like or non-neoplastic malformation inborn error tissue development. They arise virtually in all organs. may derive from any three germinal layer which mesodermal derived overgrowth is most common. are slow growing and have self-limited growth. The formation these growth take place by abnormal mixin...