XXXX : a distinctive clinicopathological entity.

@entity1 @entity27202 @entity51 @entity601 @entity272 @entity121
BACKGROUND: @entity27202 ( @entity27202 ) is a distinctive form of spinal dysraphism characterized by 2 constant features: a focal "closed" @entity601 and a fibroneural stalk that links the @entity272 to the underlying cord. The embryogenesis is hypothesized to be incomplete disjunction between cutaneous and neural ectoderms, thus preventing complete midline skin closure and allowing persistence of a physical link (fibroneural stalk) between the disjunction site and the dorsal neural tube. OBJECTIVE: To illustrate these features in 51 @entity27202 @entity1 . METHODS: All @entity1 were studied with magnetic resonance imaging or computed tomography myelography, operated on, and followed for a mean of 7.4 years. RESULTS: There were 10 cervical, 13 thoracic, 6 thoracolumbar and 22 lumbar lesions. Two main types of @entity272 were saccular (21 @entity1 ), consisting of a skin-base cerebrospinal fluid sac topped with a squamous epithelial dome, and nonsaccular (30 @entity1 ), with a flat or sunken squamous epithelial crater or pit. The internal structure of a saccular @entity27202 could be a basal neural nodule, a stalk that inserts on the dome, or a segmental myelocystocele. In nonsaccular LDMs, the fibroneural stalk has variable @entity121 and complexity. In all LDMs, the fibroneural stalk was tethering the cord. Twenty-nine @entity1 had @entity51 . There was a positive correlation between neurological grade and age, suggesting progression with chronicity. Treatment consisted of detaching the stalk from the cord. Most @entity1 improved or remained stable. CONCLUSION: @entity27202 is a distinctive clinicopathological entity and a tethering lesion with characteristic external and internal features. We propose a new classification incorporating both saccular and flat lesions.
