SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Von Recklinghausen neurofibromatosis (NF1) is the most common hereditary syndrome predisposing to neoplasia. The most common symptomatic manifestation of NF1 is the plexiform neurofibroma. We describe the case of a patient with classical von Recklinghausen neurofibromatosis presenting with a giant cell tumor (GCT) of the occipital bone infiltrating a surrounding plexiform neurofibroma.
Osteoradionecrosis (ORN) is a common complication of radiation therapy. We present the first case reported in the literature of ORN involving the first and second cervical vertebrae and occipital bone in a patient who was treated with surgery and radiation therapy 9 years prior for a TxN3M0 squamous cell carcinoma of the left neck arising from an unknown primary origin. A brief review of the pathophysiology and treatment of this pathological process is also presented. Although the mandible is the most commonly affected site in the head and neck, ORN may develop in an unusual location without any preceding trauma and display an insidious but rapidly progressive course. The pathophysiology of ORN is believed to be a complex metabolic and homeostatic deficiency created by radiation-induced cellular injury and fibrosis, which is characterized by the formation of hypoxic, hypovascular, and hypocellular tissue. The irradiated bone loses its capability to increase the metabolic requirements and nutrient supply required to replace normal collagen and cellular components lost through routine wear. This results in tissue breakdown and the formation of a chronic nonhealing wound. Infection plays only a contaminant role, with trauma being a possible initiating factor. Diagnosis of ORN begins with a complete physical examination, including fiberoptic examination and biopsy of any suspicious lesion to eliminate the possibility of recurrent tumor. Treatment of ORN commonly requires the debridement of necrotic bone and hyperbaric oxygen therapy. The head and neck surgeon must possess a high degree of suspicion to promptly diagnose ORN and initiate early treatment. Because of similarities in clinical presentation, the most important step in the initial management of suspected ORN is to eliminate the possibility of tumor recurrence or a new primary.
Intracranial venous sinus thrombosis is an uncommon cause of pseudotumor cerebri. The diagnosis is often not confirmed on the rationale that treatment will not be altered. We report a case presenting a pseudotumor cerebri where the underlying pathology disclosed dural sinus thrombosis resulting from compression by an eosinophilic granuloma of the occipital bone. Routine CT of the head and Technetium-99m brain scan initially demonstrated neither tumor nor thrombosis. Plain skull x-rays subsequently revealed a lytic lesion of the occiput. When reinvestigated with CT using bone density windows the tumor was revealed. Excision of the tumor and a short course of cobalt therapy was curative. Special techniques in nuclear scanning, CT and MRI designed to improve the sensitivity for diagnosing venous sinus thrombosis are described. This case illustrates the importance of establishing a definitive diagnosis and shows the importance of pre-test consultation between clinicians and radiologists to ensure that specific investigative techniques are properly utilized.
The work is grounded on the study of 1560 case histories of a diagnosed closed craniocerebral injury. The X-ray examination showed fractures of the cranial vault only in 3.7% of cases. A comprehensive clinical analysis of 18 cases of occipital bone fractures is set forth. In case of an extremely severe condition of such patients surgical interventions have proved to be of a little effectiveness; their expediency is doubtful.
Explore the source record for details and available documents.
Upward projection of the cerebellar vermis through the tentorial hiatus is called upward vermal herniation (UVH). UVH is less common in clinical practice than uncal herniation. Even more uncommon is chronic vermal herniation and impaction in the tentorial hiatus. To illustrate this phenomenon, we present the clinical, radiological, and morphological features of vermal impaction in a patient with a postradiation osteosarcoma of the occipital bone. In spite of nearly total excision of the tumor pushing the cerebellum upward, his postoperative course was complicated by respiratory problems and an altered level of consciousness, finally resulting in death. His clinical status paralleled the computed tomographic (CT) demonstration of persistent obliteration of the supramesencephalic cistern. CT makes more reliable the detection and management of UVH, but a high index of suspicion is necessary for prevention of this complication.
Venous blood flow through the cerebral dural sinus is variable and clinically significant. It has been investigated by cadaver dissection or radiology; however, we thought that osteology might be informative. A total of 160 dried skulls were macroscopically examined for impressions on the inner surface of the occipital bone in order to interpret the sinus flow around the torcular Herophili. The continuity between the grooves for the superior sagittal sinus (SSS) and the transverse sinuses was categorized into four types. Confluence type was noted in 56 specimens (35%), in which SSS drained into a common pool of venous sinuses. Bifurcation type was noted in 22 cases (14%), in which SSS was divided to drain into the bilateral transverse sinuses. Right dominant type was the most frequent one with 66 cases (41%), in which SSS drained only into the right transverse sinus. Left dominant type was the least frequent one with 16 cases (10%), in which SSS drained to the left, in a mirror image to the right dominant type. Clinical significance is discussed with our preliminary trial for the optimization of the inner skull surface and venous flow using computed tomography and magnetic resonance imaging, and demonstration of cerebrovascular disease.
BACKGROUND: Ewing's sarcomas account for approximately 10% of primary malignant bone tumors. While most of the primary Ewing's sarcomas occur in the long bones, pelvis, or ribs, approximately 1-6% of these sarcomas arise in the skull. We found approximately 50 cases of Ewing's sarcoma of the calvarium reported in our search of the literature. Of these, 36 cases were reported in detail. CASE REPORT AND DISCUSSION: In this article we describe a rare case of primary Ewing's sarcoma of the occipital bone presenting with acute obstructive hydrocephalus and review the literature.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Murine Hox genes have been postulated to play a role in patterning of the embryonic body plan. Gene disruption studies have suggested that for a given Hox complex, patterning of cell identity along the antero-posterior axis is directed by the more 'posterior' (having a more posterior rostral boundary of expression) Hox proteins expressed in a given cell. This supports the 'posterior prevalence' model, which also predicts that ectopic expression of a given Hox gene would result in altered structure only in regions anterior to its normal domain of expression. To test this model further, we have expressed the Hox-4.2 gene more rostrally than its normal mesoderm anterior boundary of expression, which is at the level of the first cervical somites. This ectopic expression results in a homeotic transformation of the occipital bones towards a more posterior phenotype into structures that resemble cervical vertebrae, whereas it has no effect in regions that normally express Hox-4.2. These results are similar to the homeotic posteriorization phenomenon generated in Drosophila by ectopic expression of genes of the homeotic complex HOM-C (refs 7-10; reviewed in ref. 3).
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.