[The role of dysembryogenesis in the development of spinal cord tumors]. / Rol' dyzembriohenezu u rozvytku pukhlyn spynnoho mozku.

Experience of treatment of 36 patients with extramedullary spinal cord tumors is summarized. Pigmented macules, papillomas or the spinous processes painfulness while irritation were determined on skin in accordance to tumor localization in the innervation zone of one or two segments.

[Intracerebral schwannoma. Apropos of a case]. / Schwannome intra-cérébral. A propos d'un cas.

The authors report a case of intracerebral Schwannoma discovered in a 13 year old girl who had shown symptoms of increased intracranial pressure since four years and half evolving progressively to aggravation. CT scan images and operating appearance were uncharacteristic. Histological diagnosis of the tumor was only established at pathological examination. The tumor recurred 15 months after in spite of its complete extirpation. The characteristics of this extremely rare localization of Schwannoma (14 cases published in the literature) are pin-pointed by the authors.

Incidence and ultrastructure of rudimentary cilia in benign and malignant peripheral nerve tumors.

The incidence and ultrastructure of cilia were examined in 26 peripheral nerve tumors. The cilia had the common features of elongated shafts and basal structures consisting of two basal bodies. The basal body contained two basal feet and some long striated rootlets. The cilia lacked central tubules and two dynein arms of subfiber A, suggesting that they were nonmotile and rudimentary. The quantitative results showed that the incidence of cilia was low in Schwann cells and fibroblasts of the 20 benign tumors and slightly higher in perineurial cells of the 12 neurofibromas. Conversely, the incidence was high in most of the 6 malignant tumors. Only one perineurial cell from normal mature nerve examined carried a cilium, although no cilia were seen in the other perineurial cells, Schwann cells, and fibroblasts observed. The results showed that ciliary formation was more marked in the more actively proliferating tissues such as malignant tumors, and less so in the less actively proliferating tissues such as benign tumors. Ciliary formation may be one of the ultrastructural features commonly observed in proliferative tissues.

Ectomesenchymoma. A malignant tumor of migratory neural crest (ectomesenchyme) remnants showing ganglionic, schwannian, melanocytic and rhabdomyoblastic differentiation.

A case is reported in which a tumor containing elements of mature and immature ganglioneuroma, Schwannoma, clusters of apparently benign melanocytes and embryonal rhabdomyosarcoma presented as a right-sided facial mass in a six-month-old child. Different elements of the tumor were intimately intermingled without distinct borders. Embryogenesis of the tumor, which is thought to arise from remnants of migratory neural crest cells (ectomesenchyme), showing multidirectional phenotypic expression is discussed. It was felt that the lesion contributed additional evidence in support of pluripotentiality of the migratory, neural crest derivatives, and their susceptibility to mutagenic and oncogenic influences.