Intracranial infantile hemangioma - rare entity and common pitfalls: A comprehensive multidisciplinary approach from Neurosurgery, Neurooncology and Neuropathology.

Objective: To review the rare entity of pediatric intracranial hemangiomas and discuss surgical pitfalls and pathophysiology in regard to cerebral edema formation.

Materials And Methods: We describe an extremely rare case of intracranial infantile hemangioma in a neonate with massive cerebral edema, surgically resected urgently because of acute herniation. We review the literature of 46 other pediatric cases of intracranial hemangioma, including congenital capillary hemangiomas.

New surgical paradigm for open neural tube defects.

Introduction: An open neural tube defect (ONTD) features an exposed, unclosed neural plate in the form of an expanded, flat, and frequently hefty neural placode. Traditional philosophy of ONTD repair aims at preserving function at any cost, which often means stuffing the entire thick and unwieldy but non-functional placode into a tight dural sac, increasing the likelihood of future tethering of the spinal cord. The same philosophy of attempting to save the whole perimetry of the placode also sometimes leads to inadvertent inclusion of parts of the squamous epithelial membrane surrounding the placode into the reconstructed product, only to form inclusion dermoid cyst causing further injury to the neural tissues.

Unjoined primary and secondary neural tubes: junctional neural tube defect, a new form of spinal dysraphism caused by disturbance of junctional neurulation.

Introduction: Primary and secondary neurulation are the two known processes that form the central neuraxis of vertebrates. Human phenotypes of neural tube defects (NTDs) mostly fall into two corresponding categories consistent with the two types of developmental sequence: primary NTD features an open skin defect, an exposed, unclosed neural plate (hence an open neural tube defect, or ONTD), and an unformed or poorly formed secondary neural tube, and secondary NTD with no skin abnormality (hence a closed NTD) and a malformed conus caudal to a well-developed primary neural tube.

Methods And Results: We encountered three cases of a previously unrecorded form of spinal dysraphism in which the primary and secondary neural tubes are individually formed but are physically separated far apart and functionally disconnected from each other.

Limited dorsal myeloschisis associated with dermoid elements.

Introduction: Limited dorsal myeloschisis (LDM) originates from undisjointed neural and cutaneous ectoderms during primary neurulation. Its hallmark is a fibroneural stalk causing tethering on the dorsal spinal cord rostral to the conus. Its treatment is a relatively straightforward resection of the LDM stalk from the spinal cord.

Surgical treatment of complex spinal cord lipomas.

Purpose: This paper shows the long-term benefits of total/near-total resection of complex spinal cord lipomas and meticulous reconstruction of the neural placode, and specifically, its advantage over partial resection, and over non-surgical treatment for the subset of children with asymptomatic virgin lipomas.

Methods: The technique of total resection and placode reconstruction, together with technical nuances, are described in detail. We added 77 patients with complex lipomas to our original lipoma series published in 2009 and 2010, to a total of 315 patients who had had total or near-total resection and followed for a span of 20 years.

Limited dorsal myeloschisis: a not-so-rare form of primary neurulation defect.

Purpose: Limited dorsal myeloschisis (LDM) is a distinctive form of spinal dysraphism characterized by two constant features: a focal "closed" midline skin defect and a fibroneural stalk that links the skin lesion to the underlying cord. The embryogenesis is hypothesized to be incomplete disjunction between cutaneous and neural ectoderms, thus preventing complete midline skin closure and allowing persistence of a physical link (fibroneural stalk) between the disjunction site and the dorsal neural tube.

Objective: We utilize the experience gained from the management of 63 patients with LDM to illustrate these features.

Terminal myelocystocele: surgical observations and theory of embryogenesis.

Background: The structural complexity of terminal myelocystocele (TMC) precludes a recognizable link to spinal cord development and therefore a plausible embryogenetic theory.

Objective: To demystify TMC using clinical, imaging, surgical, electrophysiological, and histopathological data and to propose a theory of embryogenesis.

Methods: Our series consisted of 4 newborns and 6 older children.

Spinal intradural, extramedullary anaplastic ependymoma with an extradural component: Case report and review of the literature.

Background: There have been 18 reported cases of primary spinal intradural, extramedullary ependymomas reported in the literature. One of the 18 cases had an extradural component and was benign. Our case is the second spinal intradural, extramedullary ependymoma with an extradural component and the first with its initial presentation as an anaplastic ependymoma.

Retained medullary cord in humans: late arrest of secondary neurulation.

Background: Formation of the caudal spinal cord in vertebrates is by secondary neurulation, which begins with mesenchyme-epithelium transformation within a pluripotential blastema called the tail bud or caudal cell mass, from thence initiating an event sequence proceeding from the condensation of mesenchyme into a solid medullary cord, intrachordal lumen formation, to eventual partial degeneration of the cavitatory medullary cord until, in human and tailless mammals, only the conus and filum remain.

Objective: We describe a secondary neurulation malformation probably representing an undegenerated medullary cord that causes tethered cord symptoms.

Method: We present 7 patients with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac, complete with issuing nerve roots, which, except in 2 infants, produced neurological deficits by tethering.

Limited dorsal myeloschisis: a distinctive clinicopathological entity.

Background: Limited dorsal myeloschisis (LDM) is a distinctive form of spinal dysraphism characterized by 2 constant features: a focal "closed" midline defect and a fibroneural stalk that links the skin lesion to the underlying cord. The embryogenesis is hypothesized to be incomplete disjunction between cutaneous and neural ectoderms, thus preventing complete midline skin closure and allowing persistence of a physical link (fibroneural stalk) between the disjunction site and the dorsal neural tube.

Objective: To illustrate these features in 51 LDM patients.