Rudimentary cephalocele or neural crest remnant?

Abstract

Three cases of the so-called rudimentary cranial meningocele/encephalocele are presented. A review of the literature yielded a number of similar cases which were tabulated and analyzed. It is suggested that this group of lesions represents neural crest remnants for which there is a good prognosis, distinct from the true meningocele/encephalocele complex.

A Case of Rudimentary Lateral Parietal Cephalocele: Extracranial Meningothelial and Glial Tissue without Intracranial Communication or Bony Defect

“…The lesion contained glial elements with surrounding meningeal tissue that converged to a definable stalk; however, no continuity between the lesion and cerebral parenchyma was identified. This entity has subsequently been given a variety of names, including atretic cephalocele, heterotopic neural rest, ectopic glial tissue, congenital head tumor, meningocele manqué and nasal glioma (when specifically occurring in the nasofrontal region) [1, 2,4,5,6]. Rudimentary cephaloceles are considered to be a distinct pathologic diagnosis from classic cephaloceles [2, 7].…”

“…Rudimentary cephaloceles are described as atrophic skin-covered scalp lesions that may be either solid or cystic, occur frequently in the posterior midline, may contain CSF-like fluid, and are often marked by alopecia or a dark ‘hair collar’ sign [1, 4, 6, 8]. On surgical and histological examination, these lesions demonstrate extracranial meningeal and often glial tissue [1, 2].…”

“…On surgical and histological examination, these lesions demonstrate extracranial meningeal and often glial tissue [1, 2]. Generally, they are characterized as terminating in a fibrous core or tract that extends through bony defect to attach to the dura mater [7].…”

“…Rudimentary cephaloceles are characterized by extracranial meningeal and glial cells, usually with a midline intracranial connection through a bony defect [1, 2]. The authors present a case of a right lateral parietal scalp lesion that on two occasions drained clear fluid similar in appearance to cerebrospinal fluid (CSF), and contained extracranial glial cells; however, no bony defect or identifiable communication with the intracranial compartment was present.…”

Atretic Cephalocele: Contribution of Magnetic Resonance Imaging in Preoperative Diagnosis

“…Atretic, occult, abortive or rudimentary cephaloceles are defined as skin-covered midline subscalp lesions that contain meninges and rests of glial and/or central nervous system tissue. These rare lesions generally occur within a few centimeters of the lambdoid suture, and 50% of them are parietal in location [1, 2, 3, 4]. We report a case of atretic parietal cephalocele documented on MRI and MR venogram, and speculate on its genesis in the context of the literature available.…”