Hypopharyngeal Diffuse Large B-Cell Lymphoma in a 74-Year-Old Man Presenting with Dysphagia: A Case Report

BACKGROUND Malignant lymphomas can occur at various sites. Hypopharyngeal tumors are at risk for airway obstruction and require rapid diagnosis and treatment. Most hypopharyngeal malignancies are squamous cell carcinomas; other tumors are rare. To date, only a few cases of malignant hypopharyngeal lymphoma have been reported, and its specific characteristics are unknown. Herein, we report a case of right hypopharyngeal diffuse large B-cell lymphoma (DLBCL) in a 74-year-old man with dysphagia. CASE REPORT A 74-year-old man presented to our hospital with dysphagia. He had no relevant medical history. Endoscopic examination revealed a right hypopharyngeal tumor. The surface of the tumor was smooth, with no evidence of hemorrhage. Computed tomography revealed a 40-mm mass located in the hypopharynx. We performed a tracheotomy and biopsy of the tumor. Histopathological examination revealed a diffuse proliferation of large atypical B cells with negative staining for Epstein-Barr virus by in situ hybridization. Immunohistochemical staining was positive for CD20 but negative for CD3 and CD10. The patient was administered chemotherapy. The tumor reduced in size, and the patient recovered completely. During the two-year follow up, no recurrence of cancer was observed. CONCLUSIONS Although most hypopharyngeal tumors are squamous cell carcinomas (SCCs), the possibility of other types of tumors should also be considered. Malignant lymphoma of the hypopharynx is rare, and more cases need to be studied and reported in the future.

Endoscopic Resection of a Massive Pleomorphic Adenoma of the Nasal Septum

Pleomorphic adenoma is a benign tumor that commonly arises from the major salivary glands, such as the parotid and submandibular glands. However, they rarely originate from the nasal cavity. Herein, we describe the case of a 49-year-old woman who presented with nasal obstruction. Preoperative evaluation revealed a giant pleomorphic adenoma attached to the nasal septum. Transnasal endoscopic removal was successfully performed using a specimen retrieval bag. We performed an endoscopic complete en-bloc resection of a large pleomorphic adenoma in the nasal cavity, using a specimen retrieval bag. There were no complications seen, no local recurrences after 2 years of follow-up, and the patient satisfaction was high. We therefore recommend that this technique of using specimen retrieval bags can be favorably utilized for endoscopic removal of large nasal tumors like pleomorphic adenoma.

Cervical Emphysema and Pneumomediastinum Caused by a Nasogastric Tube: A Case Report

BACKGROUND The nasogastric tube (NGT) is a common medical device, and serious complications associated with NGT insertions are rare. The most common serious complication is tracheal insertion; cervical emphysema and pneumomediastinum are rare. There are several methods for confirming the location of the NGT, but a single method of confirmation is often inadequate. Confirmation by air insufflation into the NGT is currently not recommended and is highly invasive. Here, we report a case of cervical emphysema and pneumomediastinum caused by an NGT. CASE REPORT A 94-year-old woman experienced a stroke and was hospitalized for neurosurgery. The nurse inserted an NGT and performed insufflation, but air sounds were not detected. Chest radiography did not reveal the tip of the NGT. Computed tomography (CT) revealed cervical emphysema, pneumomediastinum, an NGT bent in the esophagus, and the distal end of the NGT in the nasopharynx. Nasopharyngeal endoscopy revealed damaged nasopharyngeal mucosa and the distal end of the NGT. The patient was diagnosed with insufflated air passing through the damaged nasopharynx, which had spread to the cervical area and mediastinum. The NGT was removed, and the patient was treated with antibiotics. CT showed cervical emphysema, and the pneumomediastinum resolved after 20 days. CONCLUSIONS It is important to recognize that there are numerous serious and unexpected complications associated with NGT. Different methods should be considered and used to confirm the location of an NGT. Further studies on the confirmation methods and dissemination of such knowledge are required to reduce NGT complications.

Stapes Bar-Normal Stapedial Superstructure with a Mobile Footplate Fixed to the Promontory

This report describes a case of stapedial superstructure fixation with a mobile footplate, which is a rare occurrence among the ossicular malformations that cause conductive hearing impairment. A 44-year-old man with symptoms of left-sided hearing impairment since childhood presented to our department. The eardrum was normal, and pure tone audiometry showed conductive hearing impairment with a three-frequency (500, 1000, and 2000 Hz) mean of 53.3 dB and a normal tympanogram result. An abnormal shadow was observed on the internal side of the left stapes during the three-dimensional reconstruction of computed tomography. We suspected a stapes malformation and performed an exploratory tympanotomy with transcanal endoscopic ear surgery. We found a bony bar between the superstructure of the stapes and the promontory. The mobility of the stapes was significantly improved by removing the bony bar. Findings of postoperative audiometry were normal after surgery. The treatment of such cases of stapedial fixation is simple, and the prognosis of hearing gain after surgery is quite good. Thus, regarding the treatment of patients with conductive hearing impairment, clinicians and surgeons should be aware of the possibility of single stapedial superstructure fixation.

A case of giant cell-rich solitary fibrous tumor in the external auditory canal

We present a rare case of giant cell-rich solitary fibrous tumor (SFT) arising at the left external auditory canal in a 31-year-old woman. The tumor was well-circumscribed and composed of spindle-shaped cells with abundant collagenous bands. Scattered multinucleate giant cells were observed, some of which lined pseudovascular spaces. Although a focal mild-hypercellular area was observed, mitoses were rare and necrosis was absent. Interstitial mast cells were scattered, especially in the hypercellular area. Immunohistochemically, CD34, vimentin, and Bcl-2 presented diffuse positivity. Moreover, both mononuclear spindle cells and multinucleate cells showed nuclear STAT6 positivity, while NAB2-STAT6 fusion gene could not be detected by reverse transcription polymerase chain reaction using formalin-fixed specimen. These findings suggest the pathological diagnosis of giant cell-rich SFT, previously known as giant cell angiofibroma, which is a rare variant of SFT with multinucleate giant cells and occurs predominantly in orbital region. Although giant cell-rich SFTs of extra-orbital sites have been reported, to our knowledge, this is the first case arising in the external auditory canal. Giant cell-rich SFT should be considered as a differential diagnosis of spindle cell lesion with multinucleate giant cells, and STAT6 immunohistochemistry should be performed to distinguish this rare tumor from other mesenchymal neoplasms.

Stimulation of denervated muscle promotes selective reinnervation, prevents synkinesis, and restores function

OBJECTIVES/HYPOTHESIS

Previously, electrical stimulation of denervated canine laryngeal muscle was shown to promote reinnervation by native over foreign motoneurons. The goal of this study was to assess the effect of different stimulus paradigms on reinnervation quality and functional recovery.

STUDY DESIGN

A prospective study of six canines over 8 to 20 months.

METHODS

A clinical model of laryngeal paralysis was used, where recurrent laryngeal nerves of the animals were sectioned and ventilation compromised. The abductor, posterior cricoarytenoid (PCA) muscles were implanted bilaterally with electrodes from an implantable pulse generator. Animals were randomly assigned to three groups to assess the effect of different stimulus paradigms: 1) 40 pulses per second (pps) train, 2) 10 pps train, 3) no stimulation. Spontaneous vocal fold movement was measured endoscopically during hypercapnia. Exercise tolerance was measured on a treadmill using pulse oximetry. In the terminal session, electromyography (EMG) potentials were recorded during superior laryngeal nerve stimulation to index foreign reinnervation of the PCA by reflex glottic closure (RGC) motoneurons.

RESULTS

After reinnervation started, nonstimulated and stimulated 40 pps animals displayed paradoxical closure of the glottis during hypercapnia and severely decreased exercise tolerance due to faulty reinnervation. In contrast, stimulated 10 pps animals displayed minimal paradoxical closure and normal exercise tolerance (12 minutes up to 8 mph). EMG findings in this group demonstrated significantly less PCA reinnervation by foreign RGC motoneurons.

CONCLUSION

PCA stimulation with low frequency reduced synkinetic reinnervation by foreign RGC motoneurons. Paradoxical closure of the glottis with inspiration was reduced and exercise tolerance restored to normal.

Bilateral motion restored to the paralyzed canine larynx with implantable stimulator

OBJECTIVES/HYPOTHESIS

Bilateral stimulation of posterior cricoarytenoid (PCA) muscles offers a physiologic approach to restore ventilation to a normal level in case of bilateral laryngeal paralysis. The objective of this study was to evaluate the long-term efficacy and safety of a new generation stimulator in restoring ventilation and exercise tolerance.

STUDY DESIGN

A prospective study of four canines over 8-20 months.

METHODS

A Genesis XP stimulator and electrodes were implanted and recurrent laryngeal nerves were sectioned and repaired bilaterally. In bimonthly sessions, vocal fold movement resulted from PCA stimulation or induced hypercapnea, was measured endoscopically in the anesthetized animal. Exercise tolerance was measured on a treadmill and swallowing function was examined endoscopically and radiographically.

RESULTS

During the denervation phase, there was minimal ventilatory compromise and near-normal exercise tolerance. PCA stimulation produced only nominal abduction. During the reinnervation phase, synkinetic reinnervation became significant, resulting in a narrowed passive airway and paradoxical glottic closure during hypercapnea. Animals were stridorous and could walk for only 1-2 minutes. Bilateral PCA stimulation increased glottal area, equaling that of a normally innervated animal. Exercise tolerance was also normal. The optimal stimulus paradigm for the synkinetically reinnervated larynx was not different from that for the innervated larynx. Stimulation remained efficacious over the study period. Lead integrity could be maintained by prevention of device migration. There was no evidence of aspiration.

CONCLUSIONS

This study demonstrates that ventilatory compromise only occurs following faulty reinnervation. Bilateral PCA stimulation can restore ventilation and exercise tolerance completely without aspiration over the long term.

Laryngeal plexiform schwannoma as first symptom in a patient with neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by bilateral vestibular schwannomas. The initial symptoms of NF2 are usually hearing loss and tinnitus caused by vestibular schwannomas. Although other intracranial, spinal, or skin tumors also occur in NF2, laryngeal lesions are very rare. We report a rare case of NF2 with laryngeal plexiform schwannoma as first symptom. A 38-year-old man presented with a smooth-surfaced submucosal supraglottic mass. Two round masses in the left chest wall and left supraclavicular fossa were noted incidentally during investigation of the laryngeal mass. Magnetic resonance imaging (MRI) findings for these masses were identical to those of the laryngeal mass. No typical symptoms related to NF2 were identified. Histologically, the laryngeal tumor represented plexiform schwannoma. We thus considered that the two round masses in the left chest wall and left supraclavicular fossa might also represent plexiform schwannomas. NF2 was suspected, as a high incidence of multiple plexiform schwannomas has been suggested for patients with NF2. MRI of brain lesions demonstrated bilateral vestibular schwannomas and multiple meningiomas. Finally, NF2 with laryngeal plexiform schwannoma was diagnosed. Recognizing that multiple plexiform schwannomas could be associated with NF2 is important.

Rehabilitation of bilaterally paralyzed canine larynx with implantable stimulator

OBJECTIVES/HYPOTHESIS

Bilateral stimulation of the posterior cricoarytenoid (PCA) muscles offers a physiologic approach to rehabilitate ventilation to a normal level in case of bilateral laryngeal paralysis. The objective was to evaluate the safety and efficacy of a new generation stimulator in restoring glottal opening, ventilation, and exercise tolerance.

STUDY DESIGN

A prospective study in three canines over 6 to 17 months.

METHODS

A Genesis XP stimulator and electrodes were surgically implanted, and the recurrent laryngeal nerves sectioned/repaired bilaterally. In bimonthly sessions, vocal fold movement was measured endoscopically in the anesthetized animal. The movement resulted from PCA stimulation or hypercapnea during spontaneous breathing. Exercise tolerance was measured on a treadmill using pulse oximetry and swallowing function examined by videofluoroscopy.

RESULTS

During the denervation phase, there was minimal ventilatory compromise and near normal exercise tolerance with the device off (12 minutes, up to 8 mph). PCA stimulation produced only nominal abduction. During the reinnervation phase, synkinetic reinnervation became significant with narrowed passive airway and paradoxical closure of the glottis during hypercapnea. Animals were stridorous and could walk for only 1 to 2 minutes at 4 mph. With the device activated, bilateral PCA stimulation increased glottal area from 50 mm(2) to 250 mm(2), even during hypercapnea, equaling that of a normally innervated animal. Exercise tolerance was normal. There was no evidence of aspiration during deglutition.

CONCLUSIONS

This study demonstrates that severe ventilatory compromise only occurs following faulty reinnervation of laryngeal muscles. Bilateral PCA stimulation can result in complete rehabilitation of ventilation and exercise tolerance without impairment of swallowing.

Evaluation of a deep brain stimulation electrode for laryngeal pacing

OBJECTIVES

The purpose of the present study was to evaluate the suitability of a deep brain stimulation electrode for laryngeal pacing. Of interest was whether the smaller and more closely spaced channels could provide sufficient channel redundancy, controlled current distribution, and discrete activation of the posterior cricoarytenoid (PCA) muscle.

METHODS

A study was conducted in dogs under differing states of PCA muscle innervation representing complete denervation to complete synkinetic reinnervation. In 3 animals, stimulated glottal opening was assessed in the innervated state and after chemical denervation by pancuronium bromide. In 3 additional dogs, the left side of the larynx was surgically denervated and compared to the innervated, right side to study an anatomic model of clinical paralysis.

RESULTS

The thresholds were lower and the maximum level of abduction was greater for the innervated state. The stimulated glottal opening equaled that of a spontaneously breathing animal. Abductory responses were obtained across all channels in the array, demonstrating its anatomic and physiological compatibility for this application. In the denervated state, responses were only 20% of that of the innervated state with a pulse duration of 0.5 ms. The response could be enhanced to 40% and 60% by increasing the pulse duration to 1 and 2 ms.

CONCLUSIONS

A deep brain stimulation electrode could effectively reanimate the PCA muscle to a normal level in a case of synkinetic reinnervation and to as much as 60% of the normal level in a case of complete denervation.

R430 – Glycogen Depletion for Study of Neuromuscular Connectivity

Problem

A useful technique for characterizing connectivity between nerve and muscle involves prolonged electrical stimulation of nerve fibers to deplete glycogen in their target muscle fibers. Depleted muscle fibers appear blank when stained by the PAS technique. Unfortunately, results are inconsistent over a wide range of stimulus paradigms. The aim of this study was to identify other factors that may impact glycogen depletion.

Methods

Glycogen depletion was examined in the rat medial gastrocnemius muscle because of the presence of aerobic fiber types I and IIA, which are resistant to depletion. Tension and EMG were monitored during maximal stimulation of transected sciatic nerve with a 333 msec pulse train delivered at 40 Hz every second over a period of 1 hour. Once an effective paradigm was identified, depletion of an entirely aerobic muscle (i.e., soleus) was evaluated.

Results

Animals maintained in a light plane of anesthesia with a steady rate of pentobarbital IP infusion showed an average depletion of only 72%. Animals administered a progressively increasing level of anesthesia with continued stimulation until complete loss of muscular response showed a significantly greater depletion of 96%. However, when this paradigm was applied to the soleus, only 37% of the muscle depleted. Further investigation determined that co-contraction of gastrocnemius with soleus resulted in unloading of the slower soleus. Disruption of the gastrocnemius insertion on the Achilles tendon shifted the load to the soleus and increased soleus depletion to 93%.

Conclusion

Muscle fibers of any motor unit type can be identified with 93–96% accuracy when nerve stimulation is applied to an isometrically loaded muscle that is in a state of progressive barbiturate anesthesia.

Significance

Glycogen depletion provides a method for identifying the number, types, and distribution of muscle fibers in a muscle that have reinnervated, important in the assessment of nerve regeneration.

Support

NIH grants R01 DC001149 and R01 DC008429.

Fos expression in the brainstem nuclei evoked by nasal air-jet stimulation in rats

BACKGROUND

Noxious stimulation of the nasal mucosa may induce protective reflexes in the upper airway in rats. Previously, we have reported that nasal air-jet stimulation increases the activities of the laryngeal muscles in decerebrate cats; however, the neuronal mechanism of this phenomenon still is not clarified.

METHODS

After the application of nasal air-jet stimulation for 2 hours, we investigated the distribution of Fos-positive cells (FPCs) throughout the medulla compared with sham-operated rats using Fos immunoreactivity.

RESULTS

FPCs in the spinal trigeminal nucleus, the parvocellular reticular nucleus, and the nucleus of the solitary tract were more frequent than the sham-operated rats.

CONCLUSION

These results suggest that the afferents induced by air-jet stimulation were conveyed to these FPCs and that some of these cells might participate in the augmentation of laryngeal muscle activities during nasal air-jet stimulation.

Functional electrical stimulation of laryngeal adductor muscle restores mobility of vocal fold and improves voice sounds in cats with unilateral laryngeal paralysis

Functional electrical stimulation (FES) has been proposed as a potential treatment for restoring motor functions of denervated motor systems. We investigated whether FES of paralyzed laryngeal adductor muscles could restore adduction to the vocal folds. In addition, we studied the effect of stimulated vocal fold adduction on the intensity and overall quality of voice production. We recorded movement of the vocal fold, electromyographic activity of muscles recruited for vocalization, and sound production in unanesthetized decerebrate cats during FES of the paralyzed thyroarytenoid (TA) muscle. FES of the paralyzed TA muscle induced adduction of the vocal fold. Appropriate stimulus parameters for induction was 1.5-3.0 mA intensity pulses delivered at a frequency of 30-50 pulses per second (pps). FES of the paralyzed TA muscle prolonged phonation time and increased intensity of voice sounds during vocalization induced by electrical stimulation (0.2 ms, 20-50 microA, 50 pps) of the periaqueductal gray (PAG). The quality of voice sounds evaluated by sound spectrography was shown to improve during vocalization with FES. We conclude that FES of the paralyzed laryngeal adductor muscle was effective in restoring adduction of the vocal fold and improving voice sounds impaired by unilateral laryngeal paralysis.

The neuronal circuit of augmenting effects on intrinsic laryngeal muscle activities induced by nasal air-jet stimulation in decerebrate cats

We previously demonstrated that during nasal air-jet stimulation, both the activities of intrinsic laryngeal adductor and abductor muscles persistently increase, whereas the respiratory cycle prolongs and the activity of diaphragm decreases [Am. J. Rhinol. 9 (1995) 203-208; Neurosci. Res. 31 (1998) 137-146]. The purpose of this study was to clarify the neuronal circuit underlying the augmentation of intrinsic laryngeal muscles evoked by nasal air-jet stimulation. The immunohistologic analysis of Fos-expression was reported to determine the distribution of activated neurons in cat brainstem evoked by sneeze-inducing air puff stimulation of the nasal mucosa [Brain Res. 687 (1995) 143-154]. In sneezing cats, immunoreactivity was evoked in projection areas of the ethmoidal afferents, e.g. the subnuclei caudalis, interpolaris and in interstitial islands of the trigeminal sensory complex. Immunoreactivity was also enhanced in the solitary complex, the nucleus retroambiguus, the pontine parabrachial area and the lateral aspect of the parvocellular reticular formation [Brain Res. 687 (1995) 143-154]. In the present study, we focussed on the parvocellular reticular nucleus (PRN) as a relay of the neural circuit contributed to the augmentation of intrinsic laryngeal muscles evoked by nasal air-jet stimulation. We recorded the neuronal behavior of PRN during the nasal air-jet stimulation in precollicular-postmammillary decerebrate cats. As the results, 24% (17/71) of recorded neurons which were activated orthodromically by the electrical stimulation to anterior ethmoidal nerve, increased their firing rates in response to the nasal air-jet stimulation. Furthermore, spike-triggered averaging method revealed that four of these 17 PRN neurons activated intrinsic laryngeal muscles, suggesting that such neurons have excitatory projections to the intrinsic laryngeal muscle motoneurons in the nucleus ambiguus. These results suggest that the some of PRN neuron play a role in augmentation of the intrinsic laryngeal muscles activities during nasal air-jet stimulation.