Development of a Korean Culture-Friendly Olfactory Function Test and Optimization of a Diagnostic Cutoff Value

Objectives@#. Cultural familiarity and safety must be considered when assessing olfactory ability. The YSK olfactory function (YOF) test is a new olfactory function test using culturally familiar odorants to Koreans. @*Methods@#. The YOF test comprises three subtests for threshold (T), discrimination (D), and identification (I). The identification test included eight universal and four Korean culture-friendly odorants, which were selected considering eight major functional groups. Data were obtained from 1,127 subjects over 19 years old. Subjects were classified as having normosmia (n=542), hyposmia (n=472), and anosmia (n=113) by self-reported olfactory function. The YOF test and the Korean version of the Sniffin’ stick test (KVSS-II) were performed on the same day in random order. Diagnostic cutoffs for anosmia and hyposmia were calculated using the Youden index (J). @*Results@#. The mean values for each T/D/I subtest and the total TDI score were as follows: normosmia (T, 4.6±2.3; D, 8.6±2.1; I, 11.1±1.7; TDI score, 24.2±4.5); hyposmia (T, 3.3±2.2; D, 7.1±2.5; I, 9.2±3.1; TDI score, 19.5±6.4); and anosmia (T, 1.7±1.2; D, 5.1±2.5; I, 5.0±3.2; TDI score, 11.8±5.6). The correlation coefficients between the YOF test and KVSS-II were 0.57, 0.65, 0.80, and 0.86 for T, D, I, and the TDI score, respectively (P<0.001). The diagnostic cutoffs were a TDI score ≤14.5 (J=0.67) for anosmia and 14.5(TDI score ≤21.0 (J=0.38) for hyposmia. The diagnostic efficacy of the YOF test (area under the curve [AUC], 0.88) was equivalent to that of the KVSS-II (AUC, 0.88; P=0.843; DeLong method). @*Conclusion@#. The YOF test is a new olfactory test using safe and Korean culture-friendly odorants. It showed equivalent validity with the conventional olfactory function test. Furthermore, the YOF test provides information on the major functional groups of odorants, potentially enabling a more comprehensive interpretation for patients with olfactory disorders.

An Alternative Dendritic Cell-Induced Murine Model of Asthma Exhibiting a Robust Th2/Th17-Skewed Response

PURPOSE: Simple and reliable animal models of human diseases contribute to the understanding of disease pathogenesis as well as the development of therapeutic interventions. Although several murine models to mimic human asthma have been established, most of them require anesthesia, resulting in variability among test individuals, and do not mimic asthmatic responses accompanied by T-helper (Th) 17 and neutrophils. As dendritic cells (DCs) are known to play an important role in initiating and maintaining asthmatic inflammation, we developed an asthma model via adoptive transfer of allergen-loaded DCs.METHODS: Ovalbumin (OVA)-loaded bone marrow-derived DCs (BMDCs) (OVA-BMDCs) were injected intravenously 3 times into non-anesthetized C57BL/6 mice after intraperitoneal OVA-sensitization.RESULTS: OVA-BMDC-transferred mice developed severe asthmatic immune responses when compared with mice receiving conventional OVA challenge intranasally. Notably, remarkable increases in systemic immunoglobulin (Ig) E and IgG1 responses, Th2/Th17-associated cytokines (interleukin [IL]-5, IL-13 and IL-17), Th2/Th17-skewed T-cell responses, and cellular components, including eosinophils, neutrophils, and goblet cells, were observed in the lungs of OVA-BMDC-transferred mice. Moreover, the asthmatic immune responses and severity of inflammation were correlated with the number of OVA-BMDCs transferred, indicating that the disease severity and asthma type may be adjusted according to the experimental purpose by this method. Furthermore, this model exhibited less variation among the test individuals than the conventional model. In addition, this DCs-based asthma model was partially resistant to steroid treatment.CONCLUSIONS: A reliable murine model of asthma by intravenous (i.v.) transfer of OVA-BMDCs was successfully established without anesthesia. This model more accurately reflects heterogeneous human asthma, exhibiting a robust Th2/Th17-skewed response and eosinophilic/neutrophilic infiltration with good reproducibility and low variation among individuals. This model will be useful for understanding the pathogenesis of asthma and would serve as an alternative tool for immunological studies on the function of DCs, T-cell responses and new drugs.

Usefulness of Inferior Turbinate Bone-Periosteal-Mucosal Composite Free Graft for Cerebrospinal Fluid Leakage

BACKGROUND AND OBJECTIVES: Endoscopic repair of cerebrospinal fluid (CSF) leak can avoid morbidity of open approaches and has shown a favorable success rate. Free mucosal graft is a good method, and multi-layered repair is more favorable. The inferior turbinate has been commonly utilized for the free mucosal graft, but we newly designed it as a bone-periosteal-mucosal composite graft for multilayered reconstruction. SUBJECTS AND METHOD: Four subjects with a skull base defect were treated with this method. The inferior turbinate was partially resected including the conchal bone and was trimmed according to defect size. Both bony parts and periosteum were preserved on the basolateral side of the mucosa as a composite graft. The graft was applied to the defect site using an overlay technique. RESULTS: All cases were successfully repaired without any complications. Three of them had a defect size greater than 10–12 mm, and the graft stably repaired the CSF leakage. CONCLUSIONS: Endoscopic repair of CSF leakage using inferior turbinate composite graft is a simple and easy method and would be favorable for defect sizes greater than 10 mm.

Moonlighting Activity of Secreted Inflammation-Regulatory Proteins

Moonlighting proteins exhibit multiple activities in different cellular compartments, and their abnormal regulation could play an important role in many diseases. To date, many proteins have been identified with moonlighting activity, and more such proteins are being gradually identified. Among the proteins that possess moonlighting activity, several secreted proteins exhibit multiple activities in different cellular locations, such as the extracellular matrix, nucleus, and cytoplasm. While acute inflammation starts rapidly and generally disappears in a few days, chronic inflammation can last for months or years. This is generally because of the failure to eliminate the cause of inflammation, along with repeated exposure to the inflammatory agent. Chronic inflammation is now considered as an overwhelming burden to the general wellbeing of patients and noted as an underlying cause of several diseases. Moonlighting proteins can contribute to the process of chronic inflammation; therefore, it is imperative to overview some proteins that exhibit multiple functions in inflammatory diseases. In this review, we will focus on inflammation, particularly unravelling several well-known secreted proteins with multiple functions in different cellular locations.

Development of a Gustatory Function Test for Clinical Application in Korean Subjects

PURPOSE: To obtain validated clinical values suitable for developing a gustatory function test, including umami taste, in a Korean population. MATERIALS AND METHODS: The investigation involved 297 participants with self-reported normal sense of taste and smell. Liquid solutions were used for the assessment of gustatory function. The test consisted of 30 taste solutions [six concentrations of five tastants (sweet, bitter, salty, sour, and umami)]. For evaluation of overall gustatory function, the number of detected or correctly recognized taste thresholds was combined to form a “taste score.” RESULTS: Mean values of each detection and recognition threshold for the five tastes in men were consistently lower than those of women. The 10th percentile of taste score for recognition was used as the cut-off value for distinguishing normogeusia from hypogeusia. In subgroup analysis, total taste score from recognition thresholds revealed a significant negative correlation with age, indicating lower scores for increasing age. Taste score for non-smokers was significantly higher than that of smokers, in terms of detection and recognition of taste sensitivities. CONCLUSION: This gustatory function test was easy to perform, affordable, and time-saving, with the capacity to self-produce and obtain reliable data. Gustatory function was more sensitive in young people, women, and non-smokers.

Analysis of Histopathologic Characteristic and Treatment of Sinonasal Benign Tumor

BACKGROUND AND OBJECTIVES: The main treatment modality of sinonasal benign tumor is surgical resection, and the endoscopic intranasal approach has been commonly performed since the 1990s. The objective of this study was to evaluate the recurrence rates of different sinonasal benign tumors and to analyze the diverse approaches used in their surgical treatment. SUBJECTS AND METHOD: In 270 patients who were histopathologically diagnosed with sinonasal benign tumor during a period of 20 years, histopathologic type, treatment approach, interval between first treatment and recurrence, and recurrence rate according to treatment approach were analyzed. RESULTS: Recurrence rate was higher with the intranasal approach than with the extranasal approach in inverted papilloma and angiofibroma, but the differences were not statistically significant. The proportion of the intranasal approach during the latter 10 years was higher than that during the former 10 years. There was no significant differences between the recurrence rate during the former 10 years and that during the latter 10 years for both intranasal and extranasal approaches. CONCLUSION: Based on tumor location and stage and skill of the surgeon, the intranasal approach can replace the extranasal approach with no major changes in treatment outcome.

Alternative Method for Primary Nasal Epithelial Cell Culture Using Intranasal Brushing and Feasibility for the Study of Epithelial Functions in Allergic Rhinitis

PURPOSE: Although differentiated normal human nasal epithelial (NHNE) cells can be used to study the role of human nasal epithelium, there is a need for effective culture models of nasal epithelium in sinonasal disease status, including allergic rhinitis (AR). We aimed to examine the feasibility of intranasal brushing for culture of nasal epithelial cells in AR patients and to verify the hypothesis that allergic nasal epithelial (ARNE) cells differ in histologic and physiologic characteristics. METHODS: We established a system for isolating (via intranasal brushing) and culturing (with air-liquid interface, ALI) nasal epithelial cells from healthy volunteers (n=8) and AR patients (n=8). We used this system to compare the histologic findings and physiologic characteristics of NHNE and ARNE. RESULTS: The histology results showed that fully differentiated ALI culture was obtained at least 14 days after confluence and that both ciliated and secretory cells were well differentiated in ALI culture using nasal brushing. The histology results of ARNE culture were significantly different from NHNE. The number of ciliated cells was lower, and secretory cells were more dominant in ARNE cell culture compared to NHNE cells. We also observed, by electron microscopy, loose tight junctions and short cilia in cultured ARNE cells. In addition, the mRNA level of TSLP which was one of the epithelial-derived allergic cytokines was significantly higher, and the expressions of genes involved in ciliogenesis were lower in cultured ARNE cells without allergen stimulation. CONCLUSIONS: Our findings suggest that ALI culture of ARNE cells using intranasal brushing may be an alternative method for epithelial cell culture in AR patients and that cultured ARNE cells will be useful for in vitro studies of the mechanisms at play during AR because they maintain unique allergic characteristics.

Clinical Comparison of 3D Endoscopic Sinonasal Surgery Between ‘Insect Eye’ 3D and ‘Twin Lens’ 3D Endoscopes

BACKGROUND AND OBJECTIVES: Three-dimensional (3D) imaging is gaining popularity and has been partially used in robotic surgery but not in sinonasal surgery owing to technical problems. This is not only the first pilot study to evaluate the usefulness of newly-developed ‘twin lens’ HD-3D endoscope (Machida), but also the first clinical study to compare this instrument with the pre-existing ‘insect eye’ 3D endoscope (Visionsense). MATERIALS AND METHOD: A total of 45 surgeries for cerebrospinal fluid leakage, angiofibroma, or sinonasal malignancy were performed using a 3D endoscope between November 2011 and October 2013 (‘insect eye’ Visionsense VSII 3D: 29 cases, ‘twin lens’ Machida HD-3D: 16 cases). RESULTS: Depth perception and recognition of anatomical structures were all excellent in the two 3D methods. The ‘twin lens’ HD-3D endoscope provided better image resolution and naturalness of color and showed less unfavorable phenomena such as image blurring and blackout than the ‘insect eye’ 3D endoscope. CONCLUSION: If the technical limitations are solved, the 3D endoscope will be used as a substitute and a standard tool in endoscopic sinonasal surgery rather than as supplement to the two-dimensional (2D) endoscope in the near future.

Comparison of Intranasal Ciclesonide, Oral Levocetirizine, and Combination Treatment for Allergic Rhinitis

PURPOSE: To evaluate the efficacy and safety of once-daily ciclesonide in comparison to both levocetirizine alone, and a ciclesonide/levocetirizine combination in patients with seasonal allergic rhinitis (SAR) and perennial allergic rhinitis (PAR). METHODS: Subjects exhibiting moderate to severe allergic rhinitis for longer than 1 year were randomized in an open-label, 3-arm, parallel group, multicenter study. Subjects received 200 microg ciclesonide, 5 mg levocetirizine, or a combination of both. Changes from baseline until the end-of-study visit (2 weeks following) were evaluated by reflective total nasal symptom scores (rTNSSs), reflective total ocular symptom scores (rTOSSs), physician-assessed overall nasal signs and symptoms severity (PANS), and rhinoconjunctivitis quality-of-life questionnaires (RQLQ). RESULTS: Significant improvements in rTNSS, PANS, and RQLQ in the ciclesonide monotherapy group were observed in comparison to the levocetirizine alone group. Three individual symptoms of rTNSS, including runny nose, nasal itching, and congestion, were improved in the ciclesonide-treated group. rTOSS scores for ciclesonide monotherapy improved from baseline, but no superiority over levocetirizine was shown. The absolute score and changes in rTNSS and PANS were positively correlated. Ciclesonide spray was more effective than levocetirizine in reducing nasal symptoms in both SAR and PAR patients. Ciclesonide and levocetrizine were well tolerated alone and in combination. CONCLUSIONS: Our results provide support for an AR and its Impact on Asthma (ARIA) recommendation stipulating that ciclesonide is superior to levocetirizine for the treatment of AR, with tolerable safety. Addition of levocetirizine to ciclesonide did not give further clinical benefit over monotherapy.

Hypoxia Increases Epithelial Permeability in Human Nasal Epithelia

PURPOSE: The nasal mucosa is the first site to encounter pathogens, and it forms continuous barriers to various stimuli. This barrier function is very important in the innate defense mechanism. Additionally, inflammation of the nasal sinus is known to be a hypoxic condition. Here, we studied the effect of hypoxia on barrier function in normal human nasal epithelial (NHNE) cells. MATERIALS AND METHODS: The expression levels of various junction complex proteins were assessed in hypoxia-stimulated NHNE cells and human nasal mucosal tissues. We performed real-time polymerase chain reaction analysis, western blotting, and immunofluorescence assays to examine differences in the mRNA and protein expression of ZO-1, a tight junction protein, and E-cadherin in NHNE cells. Moreover, we evaluated the trans-epithelial resistance (TER) of NHNE cells under hypoxic conditions to check for changes in permeability. The expression of ZO-1 and E-cadherin was measured in human nasal mucosa samples by western blotting. RESULTS: Hypoxia time-dependently decreased the expression of ZO-1 and E-cadherin at the gene and protein levels. In addition, hypoxia decreased the TER of NHNE cells, which indicates increased permeability. Human nasal mucosa samples, which are supposed to be hypoxic, showed significantly decreased levels of ZO-1 and E-cadherin expression compared with control. CONCLUSION: Our results demonstrate that hypoxia altered the expression of junction complex molecules and increased epithelial permeability in human nasal epithelia. This suggests that hypoxia causes barrier dysfunction. Furthermore, it may be associated with innate immune dysfunction after encountering pathogens.

Very Late Recurrent Maxillary Sinus Squamous Cell Carcinoma on the Skin Graft Site 16 years after the Treatment

Maxillary sinus cancer is anatomically located adjacent to the orbit and the skull base. Local recurrence is by far the most common cause of treatment failure and the long-term survival rates is low. Local recurrence is usually happened within 2 years after initial treatment. Late recurrence is generally defined as a recurrence 5 years after initial treatment. But, late recurrence cases of maxillary sinus cancer is very rare, especially 10 years after treatment. We report a case of late recurrence on the previous skin graft site 16 years after the treatment of maxillary sinus squamous cell carcinoma in a 66-yr-old man. The patient was treated with surgical wide excision and skin graft. No recurrence was developed after one and a half year and we discussed the pathogenesis of this very late recurrent case.

Frontal Sinus Lymphoma Presenting As Progressive Multiple Cranial Nerve Palsy

Primary frontal sinus lymphoma is a very uncommon disease. In all the previously reported cases, the presenting symptoms have been due to the tumor mass effect. We present an unusual case report of an immunocompetent patient who presented with facial palsy, and then progressively developed other cranial nerve palsies over several months. He was later diagnosed with diffuse large B cell lymphoma originating from the frontal sinus. The patient underwent chemotherapy, but eventually had to receive autologous peripheral blood stem cell transplantation. He is currently disease-free. The clinical course, diagnostic workup, and therapeutic outcome are described.

Two Cases of Diffuse Large B-cell Lymphoma of Sinonasal Tract

Nasal lymphoma is an uncommon neoplasm in the sinonasal tract. The NK/T-cell type of lymphoma is more commonly found in Asian populations. However, B-cell lymphoma is more common in the western countries whereas it is rare in Asia. Recently, we experienced two cases of sinonasal B-cell lymphoma, which are rare cases in Korea, one in an advanced stage and one in an early stage. Both patients had no specific nasal symptoms or systemic B symptoms (fever, night sweat, weight loss). As our cases demonstrate, diagnosis of B cell lymphoma is often delayed in many cases because B-cell lymphoma does not show any specific symptoms. Thus, careful physical examination and biopsy under suspicion of malignancy are important for early diagnosis of nasal lymphoma.

Rosai-Dorfman Disease of the Nasal Cavity and Nasopharynx / 대한이비인후과학회지

Rosai-Dorfman disease is a rare disorder of unknown etiology and is usually associated with benign proliferation of hematopoietic and fibrous tissue that often manifests in the head and neck region. The most common clinical presentation of this entity is bilateral, nontender cervical lymphadenopathy, but an extranodal form of the disease may develop in up to 43% of patients. We report a case of extranodal Rosai-Dorfman disease occurring in the nasal cavity and the nasopharynx. A 25-year-old male visited the clinic with a complaint of nasal obstruction for several months. Mass originating from anterior portion of septum and nasopharyngeal cavity was observed by endoscopy. Endoscopic guided incisional biopsy of the lesion was performed. The histopathologic findings revealed clusters of large, foamy histiocytes with abundant clear cytoplasm, lymphophagocytosis, and heavy infiltration of lymphocytes and plasma cells, which are the key features of Rosai-Dorfman disease.

IL-1beta Induces Lysozyme Overexpression through a Mechanism Involving ERK/p38 Mitogen Activated Protein Kinase Activation in Human Airway Epithelial Cells

BACKGROUND AND OBJECTIVES: Lysozyme, a major serous component of airway epithelial secretions, plays an important role in airway defense. However, little is understood about the regulation of its expression and the associated signaling pathway. The object of this study is to investigate the regulation of lysozyme expression, the downstream signaling pathway of lysozyme expression, and the related protein kinases under inflammatory conditions using the IL-1beta, which acts as a significant cytokine in many airway inflammations. MATERIALS AND METHODS: After the IL-1beta treatment of normal human nasal epithelial cells (NHNE), lysozyme mRNA expression was determined by RT-PCR. Expressed levels of ERK/p38 kinase were determined by Western blot analysis. RESULTS: IL-1beta treated NHNEcells had over-expressed lysozyme compared to the control group. Activated ERK/p38 kinase level showed marked increment by treating NHNE with IL-1beta. Lysozyme expression and ERK/p38 kinase levels decreased when inhibitors of ERK/p38 MAP kinases were added to the IL-1beta treated cells. Finally, expression of lysozyme and activated level of ERK/p38 MAP kinases decreased in a dominant-negative cell line even when treated with IL-1beta. CONCLUSION: From these results, we concluded that IL-1beta induces over-expression of lysozyme via ERK/p38 MAP kinase signaling pathways in airway epithelial cells.

Effects of Levocetirizine on Quality of Life in the Patients with Allergic Rhinitis

BACKGROUND AND OBJECTIVES: Allergy is a chronic disorder with undesirable consequences on the quality of life (QoL). The first aim of this study is to evaluate the impact of allergy on the QoL and to show the correlation between symptoms and categories of the QoL. The second purpose is to determine whether treatment with levocetirizine improves the QoL among allergic rhinitis patients. MATERIALS AND METHODS: A total of 412 allergic patients answered the questionnaire and its sensitivity was checked to validate its usefulness in asthma and allergic rhinitis patients. To evaluate the effect of applying levocetirizine for 1 month on the QoL among allergic rhinitis patients, a total of 94 subjects were assessed with the questionnaire and analyzed (paired t-test). To evaluate its effect on the symptoms of allergic rhinitis for the duration of 2 and 4 weeks, a total of 100 subjects were analyzed (repeated ANOVA) with the symptom questionnaire. RESULTS: Besides the physical symptoms, patients suffered from activity restriction, emotional problems, difficulty in being examined, and dissatisfaction with health status. The correlation between the questionnaire and the QoL was statistically significant. After treatment, the QoL and symptoms, except nasal congestion, were significantly improved. CONCLUSION: The questionnaire can be beneficial in assessing the QoL among allergic patients. Treatment with levocetirizine provides improvement in the QoL and lowers the symptoms score among allergic rhinitis patients.

Prognostic Factors of Nasal NK/T Cell Lymphoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nasal natural killer T (NK/T) cell lymphomas are relatively common in Asia, but the prognostic factors are not well known. The purpose of this research was therefore to evaluate those prognostic factors. SUBJECTS AND METHOD: We reviewed and analyzed the medical records of 68 patients diagnosed as nasal NK/T cell lymphomas between 1984 and 2003 at Ajou University Hospital and at Yonsei University Hospital. Prognostic factors that include age, B symptoms, serum lactate dehydrogenase (LDH) levels, Eastern cooperative oncology group (ECOG) performance status, international prognostic indices (IPI), treatment modality, and Ann Arbor tumor stages were analyzed using the methods of univariate and multivariate statistics. RESULTS: The five-year overall survival rate was 43%. By univariate analysis, we found ECOG performance status, Ann Arbor tumor stages, B symptoms, and IPI to be significant prognostic factors of nasal NK/T cell lymphoma. The multivariate analysis showed that ECOG performance status and B symptoms were significant. CONCLUSION: ECOG performance status, Ann Arbor tumor stages, B symptoms, and IPI could all be prognostic factors of the nasal NK/T cell lymphoma. Among these factors, ECOG performance status and B symptoms may be regarded more useful in diagnosis of the disease than others.

Prevalence of Frontal Recess Cells in Koreans / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: This research aimed to evaluate the prevalence of specific frontal recess cells in Koreans using the classification developed by Lee, et al. SUBJECTS AND METHOD: Frontal recess was studied using high resolution CT scans of normal 60 Koreans. RESULTS: Three volunteers were found to have sinusitis around frontal recess in CT and therefore were excluded from this study. Agger nasi cells were observed in 107 sides (94.0%), frontal cell type 1 in 26 sides (22.8%), type 2 in 16 sides (14,0%), type 3 in 9 sides (7.9%) and type 4 in 0 side (0.0%). Frontal bullar cells were observed in 16 sides (14.0%), suprabullar cells in 45 sides (39.5%) and supraorbital ethmoid cells in 3 sides (2.6%). Intersinus septal cells were observed in 10 sides (8.8%) and terminal recess in 76 sides (66.7%). CONCLUSION: This is the first study conducted about the Korean prevalence of frontal recess cells using the new classification.

Treatment Outcome of Olfactory Neuroblastoma: Analysis of 11 Cases / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Olfactory neuroblastoma is a rare tumor arising from the olfactory neuroepithelium, for which surgery is the mainstay of treatment; but there are no generally accepted treatment approaches, according to tumor stage. In this study, we present our experiences with this tumor and the results of treatment to consider the clinical analysis and treatment modality. SUBJECTS AND METHOD: All of the patients, who had been treated for olfactory neuroblastoma at Severance hospital during the past ten years, were analyzed retrospectively and each of their diagnosis of olfactory neuroblastoma was histologically confirmed. RESULTS: Eleven patients aged 8 to 70 years were assessed, and 5 year disease-free survival rate were 60%. Sixty-four percent of those patients had received surgical treatment. Craniofacial resection was used mainly as an initial surgical treatment and followed by postoperative radiotherapy in 57% of the patients. If only cervical lymph node metastasis had developed at the initial diagnosis, elective neck treatment including bilateral neck dissection was performed. Chemotherapy was used either as postoperative adjuvant therapy, initial therapy with radiotherapy or salvage therapy, but not as an initial single treatment modality. Forty-five percent of the patients had recurrence and metastasis developed after the initial treatment. In the patients with cervical lymph node metastasis (n=1) and nodal recurrence (n=2), neck dissection was effective in nodal control. CONCLUSION: Complete surgical resection and postoperative radiotherapy were the main treatment modalities of olfactory neuroblastoma. Especially, postoperative radiotherapy is an essential treatment to both early- and advanced-stage olfactory neuroblastoma. Craniofacial resection is a main surgical modality, but in early stage, limited external intervention including endoscopic mass excision can be considered. If the patient has cervical lymph node metastasis or nodal recurrence, radical neck dissection should be performed. Chemotherapy seems to be considered as an adjuvant therapy, not single treatment modality.

Retropharyngeal Lymph Node Metastasis from Olfactory Neuroblastoma: A Report of 2 Cases / 대한이비인후과학회지

Olfactory neuroblastoma is a rare, malignant neoplasm arising from the olfactory epithelium. It has an aggressive biological behavior that is characterized by local recurrence, atypical distant metastasis, and poor long-term prognosis. The incidence of cervical lymph node metastasis in olfactory neuroblastoma is variable, and treatment modalities are controversial. Moreover, few reports have been published concerning retropharyngeal lymph node metastasis from olfactory neuroblastoma. We present two cases of olfactory neuroblastoma with retropharyngeal lymph node metastasis. In addition, we provided a review of the current literature regarding olfactory neuroblastoma and retropharyngeal lymph node metastasis from olfactory neuroblastoma.