INTRODUCTION:
Limited Dorsal Myeloschisis (LDM) is a distinctive clinicopathological
entity of spinal dysraphic malformations [1]. The criteria for LDM
are a cutaneous abnormality and a fibro neural or fibro vascular-neural
stalk that connects the base of the skin lesion to a focus on the dorsal
midline of the spinal cord [1].
The pathophysiology of LDM is hypothesized to be a primary neurulation
anomaly that results in incomplete disjunction between the cutaneous and
neural ectoderms of the developing embryo [2]. Based on their
cutaneous manifestations, LDMs are classified as saccular or
non-saccular (flat) [1]. Congenital dermal sinus (CDS) is a
condition of secondary neurulation, and the stalk of CDS comprises
dermal elements rather than fibroglial tissue, making the distinction
between CDS and LDM crucial. A CDS develops when the cutaneous ectoderm
is ”pulled” to the spinal cord, whereas the fibroglial connection
happens when the neural ectoderm that makes up the spinal cord is
”stretched” to the skin with an LDM.
For the diagnosis of LDM, magnetic resonance imaging (MRI) is the gold
standard [3]. With visualization of the stalk connecting the skin or
posterior mass to the underlying spinal cord, spinal imaging can show
the characteristics of LDM [4].