Faculty Bibliography

CONTEXT: Salivary adenocarcinoma, not otherwise specified, refers to gland-forming malignancies that do not satisfy the diagnostic requirements of other 'named' malignancies. OBJECTIVE: To review the features of 11 patients with salivary adenocarcinoma, not otherwise specified. To also compare the diagnostic frequencies of 2 databases, one from the Mount Sinai Medical Center (New York, NY), the other from the Shanghai Ninth People's Hospital (Shanghai, People's Republic of China). DESIGN: Pathology files were searched to establish a database of salivary tumors. All available hematoxylin-eosin- stained slides from the resection specimens diagnosed as either adenocarcinoma, not otherwise specified, or with vague or unusual diagnoses (eg, probable carcinoma-ex-pleomorphic adenoma) were pulled from our files and reexamined. Dates of death were confirmed with the Social Security Death Index. RESULTS: We identified 11 patients with salivary adenocarcinoma, not otherwise specified, ranging in age from 49 to 80 years (median, 67 years), with a male preponderance. The parotid gland was the most common site of tumor origin. Ten of these tumors were high grade, and 1 was intermediate grade. Two patients were diagnosed at stage II, while the remaining patients were diagnosed at stage III or IV. Histologically, all tumors were invasive, with variable glandular differentiation and diverse architectural patterns. The diverse cytologic tumor cell types included cuboidal, columnar, epithelioid, polygonal, oncocytoid, clear, melanoma-like, mucinous, sebaceous, and plasmacytoid. Four patients died after 4 to 27 months (mean, 15 months), 1 patient is alive with disease at 12 months, 1 patient is disease-free at 14 years, and 3 patients remain disease-free after short follow-ups (10, 12, and 12 months). One patient had surgery just recently, and the remaining patient had no follow-up. CONCLUSIONS: Salivary adenocarcinoma, not otherwise specified, is an aggressive, high-grade malignancy, with a predisposition for the parotid gland. It is characterized by cytologic and architectural diversity and an invasive growth pattern

Dry mouth (xerostomia) is one of the most common complaints following radiation therapy (RT) for head and neck cancers. Notably, RT causes irreparable damage to salivary glands that increases the risk for severe and long-term oral and pharyngeal disorders. Several strategies in the treatment of head and neck cancers have been developed to prevent RT-induced salivary dysfunction while providing definitive oncologic therapy. These include salivary-sparing RT; cytoprotectants (such as amifostine); combination therapy of high-dose-rate intraoperative RT, external beam RT, plus a cytoprotectant; salivary gland surgical transfer; and gene therapy. Future research that incorporates biologic, pharmacologic, and technologic advancements that optimize therapeutic ratios and minimizes adverse oral sequelae is warranted.

OBJECTIVES: Multichannel auditory brainstem implants (ABI) are currently indicated for patients with neurofibromatosis type II (NF2) and schwannomas involving the internal auditory canal (IAC) or cerebellopontine angle (CPA), regardless of hearing loss (HL). The implant is usually placed in the lateral recess of the fourth ventricle at the time of tumor resection to stimulate the cochlear nucleus. This study aims to review the surgical and audiologic outcomes in 18 patients implanted by our Skull Base Surgery Team from 1994 through 2003. STUDY DESIGN: A retrospective chart review of 18 patients with ABIs. METHODS: We evaluated demographic data including age at implantation, number of tumor resections before implantation, tumor size, surgical approach, and postoperative surgical complications. The ABI auditory results at 1 year were then evaluated for number of functioning electrodes and channels, hours per day of use, nonauditory side effect profile and hearing results. Audiologic data including Monosyllable, Spondee, Trochee test (MTS) Word and Stress scores, Northwestern University Children's Perception of Speech (NU-CHIPS), and auditory sensitivity are reported. RESULTS: No surgical complications caused by ABI implantation were revealed. A probe for lateral recess and cochlear nucleus localization was helpful in several patients. A range of auditory performance is reported, and two patients had no auditory perceptions. Electrode paddle migration occurred in two patients. Patient education and encouragement is very important to obtain maximum benefit. CONCLUSIONS: ABIs are safe, do not increase surgical morbidity, and allow most patients to experience improved communication as well as access to environmental sounds. Nonauditory side effects can be minimized by selecting proper stimulation patterns. The ABI continues to be an emerging field for hearing rehabilitation in patients who are deafened by NF2

OBJECTIVES: Cochlear implant device failures and reimplantation have mainly been reported on in adults. The purpose of this study was to isolate precursors of device failures and assess the effects of reimplantation in children. METHODS: From 1997 to 2003, 27 children underwent cochlear reimplantation at our institution. The pre-failure complaints were categorized and correlated with actual failure modes and postimplantation results. Speech-recognition tests were used to evaluate pre- and post-reimplantation performance. RESULTS: Pre-failure length of usage ranged from 0 to 12 years. Symptoms including pain, intermittence, reduced performance, noise and the need for frequent device adjustments were associated with device failures, although not with a particular mode of failure. Post reimplantation performance was equal to but not immediately better than pre-failure results in children who received upgraded devices. CONCLUSIONS: Specific complaints, frequent need for device adjustments and reduced speech recognition can be precursors to device failures, underscoring the need for routine follow-up evaluations. Reimplantation with newer technology does not guarantee improved speech understanding and often requires an adjustment period to reach pre-reimplantation levels.

The purpose of this study was to evaluate the performance of the new features of the Nucleus Research Platform 8 (RP8), a system developed specifically for research purposes The RP8 consists of a research implant, a speech processor and a new NRT software (NRT v4), and includes comparisons of the different artefact-cancellation methods, NRT threshold, and recovery function measurements. The system has new artefact-suppression techniques and new diagnostic capabilities; their performance has been verified in animal experiments. In this study, NRT data were collected from 15 postlingually deafened adult cochlear implant patients intraoperatively and up to 6 months postoperatively after switch-on. The initial investigation in two clinics in Europe focused primarily on the enhanced NRT capabilities Results from the trial in two European clinics indicate that NRT measurements can be obtained with lower noise levels. A comparison of the different artefact-cancellation techniques showed that the forward-masking paradigm implemented in the Nucleus 3 system is still the method of choice. The focus of this report is on recovery function characteristics, which may give insight into auditory nerve fiber properties with regard to higher stimulation rates

HYPOTHESIS: Fixation of cochlear implants using prosthetic mesh is an improvement of the traditional fixation methods. STUDY DESIGN: A retrospective chart review was performed examining all adult and pediatric patients between 1998 and 2003 who underwent cochlear implantation using polypropylene mesh and titanium screws to fix the cochlear implant internal receiver. Patient age at implantation, postoperative infections, device failures, device migrations or extrusions, cerebrospinal fluid (CSF) leaks, flap complications, epidural hematoma data, and follow-up data were evaluated. RESULTS: Two hundred and eighty-five patients were identified who received cochlear implantation using the polypropylene mesh securing technique. There were five postoperative infections, two device failures, zero flap complications, zero device migrations or extrusions, zero cerebral spinal fluid leaks, and zero epidural hematomas. The two delayed device failures in this series were not related to fixation technique. CONCLUSIONS: We conclude that this technique is widely applicable, technically superior, and not associated with increased complications.

OBJECTIVE/HYPOTHESIS/OBJECTIVE:The utility of elective neck dissection in the management of patients with oral cavity and oropharyngeal cancer who present without neck metastases remains controversial. The study addressed the question of whether elective neck dissection improves regional control and survival in patients with squamous cell carcinoma of the oral cavity and oropharynx presenting with T1/T2 node-negative disease. STUDY DESIGN/METHODS:A nonrandomized, uncontrolled retrospective chart review. METHODS:A nonrandomized, uncontrolled retrospective chart review was performed. Resection of the primary tumor was performed in all patients. The neck was observed in one group, and elective neck dissection was performed for patients in another group. RESULTS:The study data indicated that elective neck dissection significantly improves regional control and regional recurrence-free survival. Elective neck dissection when compared with observation of the neck did not improve overall survival. CONCLUSION/CONCLUSIONS:Elective neck dissection reduces regional recurrence and may extend disease-free survival.

Despite multiple advances in medical imaging, noninvasive monitoring of therapeutic efficacy for malignant gliomas remains problematic. An underutilized observation is that malignancy induces characteristic abnormalities of vessel shape. These characteristic shape abnormalities affect both capillaries and much larger vessels in the tumor vicinity, involve larger vessels prior to sprout formation, and are generally not present in hypervascular benign tumors. Vessel shape abnormalities associated with malignancy thus may appear independently of increase in vessel density. We hypothesize that an automated, computerized analysis of vessel shape as defined from high-resolution MRA can provide valuable information about tumor activity during the treatment of malignant gliomas. This report describes vessel shape properties in 10 malignant gliomas prior to treatment, in 2 patients in remission during treatment, and in 2 patients with recurrent disease. One subject was scanned multiple times. The method involves an automated, statistical analysis of vessel shape within a region of interest for each tumor, normalized by the values obtained from the vessels within the same region of interest of 34 healthy subjects. Results indicate that untreated tumors display statistically significant vessel tortuosity abnormalities. These abnormalities involve vessels not only within the tumor margins as defined from MR but also vessels in the surrounding tissue. The abnormalities resolve during effective treatment and recur with tumor recurrence. We conclude that vessel shape analysis could provide an important means of assessing tumor activity.

Advanced MRI techniques, such as MR spectroscopy, diffusion and perfusion MR imaging can give important in vivo physiological and metabolic information, complementing morphologic findings from conventional MRI in the clinical setting. Combining perfusion MRI and MR spectroscopy can help in patients with brain masses in who the pre-operative differential diagnosis is unclear. This review demonstrates the use of dynamic, susceptibility weighted, contrast-enhanced MR imaging (DSC MRI) and magnetic resonance spectroscopic imaging (MRSI) to distinguish surgical from non-surgical lesions in the brain. There is overlap in the MRI appearance of many enhancing and ring-enhancing lesions such as gliomas, metastases, inflammatory lesions, demyelinating lesions, subacute ischemia, abscess and some AIDS related lesions. We review examples of histopathologically confirmed high-grade glioma, a middle cerebral artery territory infarct, a tumefactive demyelinating lesion and a metastasis for which conventional MR imaging (MRI) was non-specific and potentially misleading and demonstrate how DSC MRI and MRSI features were used to increase the specificity of neurodiagnosis. At several institutions, many patients routinely undergo MRI as well as MRSI and DSC MRI. Cerebral blood flow (CBF), mean transit time (MTT), and relative cerebral blood volume (rCBV) measurements are obtained from regions of maximal perfusion as determined from perfusion color overlay maps. Metabolite levels and ratios are determined for Choline (Cho), N-Acetyl Aspartate (NAA), Lactate and Lipids (LL). Metabolite levels are obtained by measuring the peak heights of each metabolite and the ratios are obtained from these measurements for Cho/Cr, Cho/NAA and NAA/Cr. Neurosurgical intervention carries substantial morbidity, mortality, financial and potential emotional cost to the patient and family. Making a pre-operative diagnosis allows the neurosurgeon to be confident in the choice of treatment plan for the patient and allays considerable patient anxiety. The utility of combining clinical findings with multi-parametric information from perfusion and spectroscopic MR imaging in differentiating surgical lesions from those which do not require surgical intervention is discussed