Dermal Sinus Tract of the Thoracic Spine Presenting with Intramedullary Abscess and Cranial Nerve Deficits.

Congenital dermal sinus tract of the spine is an unusual developmental defect which represents a failure of the surface ectoderm and dermal elements to separate from the neuroectoderm. A 15-month-old female presented with high fever, severe right hemiparesis, difficulty breathing and cranial nerve deficits. Magnetic resonance imaging (MRI) of the spine revealed a congenital dermal sinus tract at the Th6 level, an intramedullary collection extending up to the brainstem and a probable intramedullary cystic lesion. The child was operated acutely with ligation of the sinus tract, drainage of the abscess and partial removal of the intramedullary lesion. Due to abscess recurrence, she was reoperated with complete excision of the dermal sinus tract, abscess redrainage and subtotal excision of the dermoid cyst (retaining a part of its capsule). Pus culture isolated Corynebacterium species and Peptococcus species and histology of the lesion showed a dermoid cyst. Postoperatively, after an initial neurologic deterioration, she progressively improved. An MRI scan at 15 months neither showed recurrence of the collection nor regrowth of the lesion. Spinal dermal sinus tracts that remain unnoticed or untreated can result in serious complications and should be operated as soon as possible to prevent undesirable sequelae.