Congenital spinal lipomas--tumor versus hamartoma.

Congenital spinal lipomas as a form of dysraphism are frequently reported in literature. A few studies have highlighted their histologic features and found them different from lipomas in other parts of the body. In a review of eight cases of spinal lipomas, we found heterotopic tissue in seven. Neural tissue, muscle, bone and cartilage were frequently encountered. The presence of meningothelial cells in one case was an unusual finding. These findings support the concept of their hamartomatous origin. Malignancy, occurring later in life in one of the heterotopic elements is known, though uncommon, and is one of the reasons, besides neurologic deficit, for long term follow-up.