Spinal dermal sinus and pseudo-dermal sinus tracts: two different entities

Abstract

Occult spinal dysraphism (OSD) encompasses various conditions. A dermal sinus tract (DST) consists of a duct communicating to the skin with deep structures that carries an important risk of infection. A different lesion consisting of a translucent skin opening and a fibrous tract that lacks a lumen can also be found in OSD. We termed this lesion pseudo-dermal sinus tract. We reviewed clinical features of 20 patients with spinal skin orifices. The patients were classified into two categories: group 1 comprised children with true DST and group 2 included patients with skin dimples resembling a DST. The aim of this study was to analyze differential features of patients in these two groups as they behaved dissimilarly in regard to clinical significance and outcomes, especially those concerning infectious risk. Children of group 1 (n = 8) presented with tiny skin orifices and with superficial or deep infection. In contrast, group 2 (n = 12) mostly manifested with neurological symptoms. No patient in group 2 developed an infection preoperatively. In both groups, magnetic resonance showed tracts that ended in different structures. Histopathology of the lesions were dissimilar, those of group 1 being hollow tubular structures lined by epithelium while those of group 2 being solid tracts of fibrous connective tissue. DST constitutes a clinicopathological diagnosis. Although sharing some common cutaneous and neuroimaging findings, both groups behaved differently. Patients of group 1 tended to show up with infection requiring urgent surgery. Patients of group 2 often presented with neurological manifestations and skin lesions, but needed no immediate operation.