Congenital cysts of the fourth ventricle : a report of two cases associated with tumor of the optic thalamus and crus cerebri / by J. Ramsay Hunt.

  • Hunt, James Ramsay, 1872-1937.
Date:
1904
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Licence: In copyright

Credit: Congenital cysts of the fourth ventricle : a report of two cases associated with tumor of the optic thalamus and crus cerebri / by J. Ramsay Hunt. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    composed of coarse glia and an external rich in medullary nerve fibres. The interior lacks a continuous epithelial lining, but a few remnants still persist. These consist of columnar cells, flat cells, and stratified layers of cells, the latter suggesting an epithelial metaplasia. No ganglion cells were observed. Remarks. The occurrence in the brain of congenital cysts, while rare, is recognized in all classifications of the subject. They originate in offshoots of the primary cerebral vesicles. Bruns mentions, in connection with gliomata of the pons, the occurrence in the brain stem of minute cysts lined by ependyma and evidently separations from the primary neural tube. Stroebe demonstrated in gliomata of the brain minute cysts lined by columnar epithelium, probably sprouts of the primary cerebral vesicles. In spinal cord pathology the relation of central gliosis, gliomata, and syringomyelia to developmental defects and embryonal rests of the central canal is fairly well established. In brief, abnormal offshoots and diverticula of the primary neural tube in any portion of its course may furnish the incentive to morbid proliferation. Cysts of the size, location, and nature just described are unique in my pathological experience. A parasitic origin could be definitely excluded by the nature of the histological findings. In favor of a congenital origin are: 1. The cyst wall throughout was composed of medullated nerve fibres and glia. 2. The intimate relations of the cyst wall with the adjacent nerve structures as it traverses the brain stem; the cyst is not intercalated, but forms an integral part of the pons. 3. Remnants of an epithelial lining. 4. The associated neoplasms. 5. lhe absence of cerebral symptoms preceding the development of tumor. I he gross anatomical relations of the cysts in my cases suggest an origin from that portion of the medullary tube engaged in the formation of the second and third primary cerebral vesicles. The developmental changes in these vesicles, which form the mid- brain and hind-brain, are especially conspicuous and complicated. I his portion of the fetal brain is wedged in between the head and neck bend, flaring out laterally to form the expansions of the floor of the fourth ventricle, corresponding to the lateral recesses. I he evaginations of the Rauten lippen, which develop subse- quently, enfolding and covering in the ventral and dorsal zones of His, further complicate matters and would favor the occurrence of developmental defect. The frequency of gliomata in this region is well known. 6 In conclusion, I would emphasize the importance of subjecting the so-called old, sterile, parasitic cysts in the neighborhood of the ventricular cavity, to serial study and (he Weigert method before excluding a congenital origin.