Caudal Regression Syndrome in a 12-Year-Old Boy Associated with Thecal Sac Ending at Fifth Lumbar Vertebrae Associated with Caudal Stenotic Dural Sac and Thickened Filum Terminale, Bifid Lumbar Vertebrae with Sacral Vertebral Agenesis: Pentads Defects

Caudal regression syndrome is a rare congenital anomaly with characteristic agenesis or dysgenesis of caudal vertebrae varying from isolated partial agenesis of coccyx or entire lumbosacral vertebrae.1,2 It may be associated with congenital anomaly of spinal cord, genitourinary tract, and gastrointestinal tract.3–5 The children with extensive bony defects in caudal regression syndrome may present with stork leg deformity, narrow iliocostal interval, and significant smaller transverse pelvic diameter, in those cases also having complete sacrum agenesis.6–8 The authors present an interesting case in which the patient had the thecal sac extending only up to fifth lumbar vertebrae, stenotic caudal thecal sac, thickened filum terminale, bifid lumbar vertebrae, and agenesis of lower sacral and coccygeal vertebral segments.