The bone ablation characteristics of five infrared lasers, including three pulsed lasers (Nd:YAG, lambda = 1,064 micron; Hol:YSGG, lambda = 2.10 micron; and Erb:YAG, lambda = 2.94 micron) and two continuous-wave lasers (Nd:YAG, lambda = 1.064 micron; and CO2, lambda = 10.6 micron), were studied. All laser ablations were performed in vitro, using moist, freshly dissected calvarium of guinea pig skulls. Quantitative etch rates of the three pulsed lasers were calculated. Light microscopy of histologic sections of ablated bone revealed a zone of tissue damage of 10 to 15 micron adjacent to the lesion edge in the case of the pulsed Nd:YAG and the Erb:YAG lasers, from 20 to 90 micron zone of tissue damage for bone ablated by the Hol:YSGG laser, and 60 to 135 micron zone of tissue damage in the case of the two continuous-wave lasers. Possible mechanisms of bone ablation and tissue damage are discussed.
The term "endolymphatic sac tumor" (ELST) was coined to identify the likely origin of aggressive papillary tumors of the temporal bone. To evaluate the validity of this designation, the temporal bone collection at the Massachusetts Eye and Ear Infirmary was accessed in an effort to determine the pathologic relationship between these tumors and the endolymphatic sac. The search resulted in the identification of a de-novo papillary epithelial lesion arising within the confines of the endolymphatic sac in a patient with von Hippel-Lindau (VHL) disease who harbored a large, destructive ELST in the opposite temporal bone. This finding provides the most substantial evidence to date regarding the origin of the ELST and the accuracy of its nomenclature. Seven additional clinical cases of ELST were identified and analyzed in order to define the natural history of these tumors. All patients had a history of sensorineural hearing loss diagnosed an average of 10.6 years prior to tumor discovery. The presence of a polypoid external auditory canal mass, facial paralysis, and evidence of a destructive mass arising on the posterior fossa surface of the temporal bone were common physical and radiographic findings. The management of these patients, as well as those who are probably prone to such tumors (i.e., VHL patients), is discussed.
Patients diagnosed with congenital TEF/EA have a high rate of secondary upper airway anomalies. Consideration should be given to perform a complete airway evaluation in all of these patients.
To review the presentation of laryngeal neurofibroma, including its association with neurofibromatosis types 1 and 2, and present guidelines for its management. Design: Retrospective study. Patients: Five pediatric patients with laryngeal neurofibroma, 4 girls (80%) and 1 boy (20%), were treated at a tertiary pediatric medical center from 1973 through 2003. Recorded data included age at initial presentation, sex, symptoms, significant medical and family history, preoperative evaluation, location of the tumor, surgical procedure, complications, outcome, and recurrence. Results: The 5 patients presented with stridor and caféau-lait spots at or shortly after birth. All patients were diagnosed as having neurofibromatosis type 1 by the established criteria. Studies evaluating the disease processes included plain radiography, computerized tomography, magnetic resonance imaging, barium swallow, and laryngoscopy and bronchoscopy under anesthesia. Pathologic examination of biopsy specimens from all patients showed neurofibromas with plexiform and/or diffuse features. Treatments included tracheotomy (n=4), carbon dioxide laser excision (n=4), modified neck dissection (n=3), partial pharyngectomy (n=1), supraglottic laryngectomy (n=1), and endoscopic hemilaryngectomy (n=1). Three patients were successfully decannulated. Follow-up ranged from 1 to 15 years. One patient was lost to follow-up. No evidence of malignant degeneration was noted.
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