Cluster Analysis of Inhalant Allergens in South Korea: A Computational Model of Allergic Sensitization

Objectives@#. Sensitization to specific inhalant allergens is a major risk factor for the development of atopic diseases, which impose a major socioeconomic burden and significantly diminish quality of life. However, patterns of inhalant allergic sensitization have yet to be precisely described. Therefore, to enhance the understanding of aeroallergens, we performed a cluster analysis of inhalant allergic sensitization using a computational model. @*Methods@#. Skin prick data were collected from 7,504 individuals. A positive skin prick response was defined as an allergen-to-histamine wheal ratio ≥1. To identify the clustering of inhalant allergic sensitization, we performed computational analysis using the four-parameter unified-Richards model. @*Results@#. Hierarchical cluster analysis grouped inhalant allergens into three clusters based on the Davies-Bouldin index (0.528): cluster 1 (Dermatophagoides pteronyssinus and Dermatophagoides farinae), cluster 2 (mugwort, cockroach, oak, birch, cat, and dog), and cluster 3 (Alternaria tenus, ragweed, Candida albicans, Kentucky grass, and meadow grass). Computational modeling revealed that each allergen cluster had a different trajectory over the lifespan. Cluster 1 showed a high level (>50%) of sensitization at an early age (before 19 years), followed by a sharp decrease in sensitization. Cluster 2 showed a moderate level (10%–20%) of sensitization before 29 years of age, followed by a steady decrease in sensitization. However, cluster 3 revealed a low level (<10%) of sensitization at all ages. @*Conclusion@#. Computational modeling suggests that allergic sensitization consists of three clusters with distinct patterns at different ages. The results of this study will be helpful to allergists in managing patients with atopic diseases.

A Case of Brain Herniation and Cerebrospinal Fluid Leakage during Endoscopic Marsupialization of Ethmoid Sinus Mucocele / 대한이비인후과학회지

Paranasal sinus mucocele is a slowly growing benign cystic lesion. It usually involves the frontal and ethmoid sinuses and can extend to adjacent structures, especially to the orbit, skull base and brain parenchyma. Prompt surgical intervention is needed when symptoms occur. Complete resection of mucocele is approached via endoscopic sinus surgery, while marsupialization is also widely considered. Recently, we encountered a case of spontaneous brain herniation and cerebrospinal fluid leakage during endoscopic marsupialization of ethmoid sinus mucocele. Herein, we report the case with a review of the literature.

Effect of Nocturnal Hypoxia on Nocturia in Patients With Obstructive Sleep Apnea / 대한배뇨장애요실금학회지

PURPOSE: To identify the association between nocturia and obstructive sleep apnea (OSA), we compared results of polysomnography (PSG) with the presence or absence of nocturia in patients with suspected OSA. METHODS: Patients underwent PSG for suspected OSA. The International Prostate Symptom Score and quality of life (IPSS/QoL) questionnaire was evaluated to assess voiding symptoms that may affect sleep quality. The results of PSG were compared between patient groups with or without nocturia. RESULTS: In logistic regression analysis, age (odds ratio [OR], 1.052; P=0.004), diabetes mellitus (OR, 6.675; P<0.001), mean O₂ saturation (OR, 0.650; P=0.017), oxygen desaturation index (ODI) 3 (OR, 1.193; P=0.010), and ODI4 (OR, 1.136; P=0.014) affected nocturia independently among the OSA-suspected patients. CONCLUSIONS: Hypoxia caused by OSA affects the incidence of nocturia. Less desaturated OSA patients with nocturia may require more urological evaluation and treatment for nocturia even after the correction of OSA.

Higher glucagon-to-insulin ratio is associated with elevated glycated hemoglobin levels in type 2 diabetes patients

BACKGROUND/AIMS@#The importance of α-cell dysfunction in the pathogenesis of type 2 diabetes has re-emerged recently. However, data on whether relative glucagon excess is present in clinical settings are scarce. We aimed to investigate associations between glucagon-to-insulin ratio and various metabolic parameters.@*METHODS@#A total of 451 patients with type 2 diabetes naïve to insulin treatment were recruited. Using glucagon-to-insulin ratio, we divided subjects into quartiles according to both fasting and postprandial glucagon-to-insulin ratios.@*RESULTS@#The mean age of the subjects was 58 years, with a mean body mass index of 25 kg/m² The patients in the highest quartile of glucagon-to-insulin ratio had higher glycated hemoglobin (HbA1c) levels. HbA1c levels were positively correlated with both fasting and postprandial glucagon-to-insulin ratios. Subjects in the highest quartile of postprandial glucagon-to-insulin ratio were more likely to exhibit uncontrolled hyperglycemia, even after adjusting for confounding factors (odds ratio, 2.730; 95% confidence interval, 1.236 to 6.028; p for trend < 0.01).@*CONCLUSIONS@#Hyperglucagonemia relative to insulin could contribute to uncontrolled hyperglycemia in type 2 diabetes patients.

Clinical Analysis of Daytime Sleepiness and Insomnia in Patients with Obstructive Sleep Apnea

BACKGROUND AND OBJECTIVES: Sleep disturbances and excessive daytime sleepiness (EDS) are the major symptoms of obstructive sleep apnea (OSA). This study aimed to investigate clinical implications of insomnia and EDS in patients with OSA using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). MATERIALS AND METHOD: We evaluated 131 subjects with suspected OSA who were undergoing polysomnography (PSG) and performing the PSQI and ESS surveys. OSA was diagnosed when the apnea-hypopnea index was five or more. EDS was defined when ESS score was 11 points or higher. Detailed history and questionnaire were used to categorize insomnia. We compared clinical variables and PSG results in subgroups with or without insomnia and EDS. RESULTS: There were no significant differences of PSQI and ESS score between controls and OSA. OSA with insomnia had significantly increased total score (p < 0.001) and decreased total sleep time (p=0.001) and sleep efficiency (p=0.001) on the PSQI compared to those without insomnia. OSA with EDS showed significantly increased PSQI score (p=0.022) and decreased total sleep time (p=0.018) on PSG compared to those without EDS. Neither PSQI nor ESS score had a correlation with respiratory variables such as AHI and oxygen saturation. Total sleep time had a significant effect on both insomnia and EDS in patients with OSA. CONCLUSION: Decreased total sleep time had important effects on subjective symptoms of OSA and comorbid insomnia. Therefore, restoration of decreased sleep time is important in the management of OSA.

Gender-specific cephalometric features related to obesity in sleep apnea patients: trilogy of soft palate-mandible-hyoid bone / 대한악안면성형재건외과학회지

BACKGROUND@#The aim of this study is to investigate the relationship between gender-specific and obesity-related airway anatomy in patients with obstructive sleep apnea (OSA) by using cephalometric analyses.@*METHODS@#We retrospectively evaluated 206 patients with suspected OSA undergoing polysomnography and anthropometric measurements such as body mass index, neck circumference, and waist-hip ratio. We checked lateral cephalometry to measure tissue landmarks including angle from A point to nasion to B point (ANB), soft palate length (SPL), soft palate thickness (SPT), retropalatal space (RPS), retrolingual space (RLS), and mandibular plane to hyoid (MPH).@*RESULTS@#Male with OSA showed significantly increased SPL (P = .006) compared with controls. SPL and MPH had significant correlation with apnea-hypopnea index (AHI) and central obesity. Female with OSA showed significantly increased ANB (P = .013) and SPT (P = .004) compared with controls. The receiver operating characteristic curves revealed that SPT in male and ANB and SPT in female were significant in model 1 (AHI ≥ 5) and model 2 (AHI ≥ 15). MPH was also significant for male in model 2.@*CONCLUSION@#Male and female with OSA had distinct anatomic features of the upper airway and different interactions among soft palate, mandible, and hyoid bone.

Bacterial Ball as an Unusual Finding in Patients With Chronic Rhinosinusitis

OBJECTIVES: Pathophysiology of chronic rhinosinusitis (CRS) is very complex and has not yet been clearly understood. To date, various factors have been researched to have relations with the pathogenesis of CRS, such as superantigens and biofilms. Recently, we found an unusual pathological finding in patients with CRS, and we called this new entity as bacteria ball (or bioball). In this study, we analyze the clinical characteristics of bacteria ball occurred in CRS. METHODS: This study enrolled consecutive 247 patients with CRS who underwent functional endoscopic sinus surgery from January 2015 to August 2016. The diagnosis of bacterial ball was made when negative in Gomori-methenamine-silver stain and positive in Gram stain. Histologically, bacterial ball was defined as acellular mucous materials with bacterial colonies and inflammatory cell infiltrates. We compared clinical data and computed tomography (CT) findings between fungal and bacterial balls. RESULTS: Six cases (2.4%) of CRS were confirmed histologically as bacterial ball. Most of them were found in the maxillary sinus of CRS without nasal polyposis (66.7%). Bacterial ball was green or brown colored materials similar to fungal ball which was harder and tightly adherent to the antral mucosa. Compared to fungal ball, patients with bacterial ball showed significantly less peripheral eosinophils (P=0.011) and calcification in CT scans (P=0.003). CONCLUSION: Bacterial ball is unusual findings occurred in patient with CRS which is different from fungal ball and biofilm. For diagnosis of bacterial ball, Gram stain is essentially required to identify bacterial colonies. Bacterial ball might appear to be evidence of a new strategy for living in the paranasal sinuses.

The Effectiveness of Budesonide Nasal Irrigation After Endoscopic Sinus Surgery in Chronic Rhinosinusitis With Asthma

OBJECTIVES: Budesonide nasal irrigation was introduced recently for postoperative management of patients with chronic rhinosinusitis. The safety and therapeutic effectiveness of this procedure is becoming accepted by many physicians. The objective of this study was to evaluate the efficacy of postoperative steroid irrigation in patients with chronic rhinosinusitis and asthma. METHODS: This prospective study involved 12 chronic rhinosinusitis patients with nasal polyps and asthma who received oral steroid treatment for recurring or worsening disease. The 22-item Sinonasal Outcomes Test (SNOT-22) and Lund-Kennedy endoscopy scores were checked before nasal budesonide irrigation, and 1, 2, 4, and 6 months after irrigation. We also calculated the total amount of oral steroids and inhaled steroids in the 6 months before irrigation and the 6 months after it. RESULTS: The mean SNOT-22 score improved from 30.8±14.4 before irrigation to 14.2±8.7 after 6 months of irrigation (P=0.030). The endoscopy score also improved from 7.4±4.7 before irrigation to 2.2±2.7 after 6 months (P<0.001). The total amount of oral steroid was decreased from 397.8±97.6 mg over the 6 months before irrigation to 72.7±99.7 mg over the 6 months after irrigation (P<0.001). CONCLUSION: Nasal irrigation with budesonide is an effective postoperative treatment for chronic rhinosinusitis with asthma, which recurs frequently, reducing the oral steroid intake.

Clinical Implications of Snoring Time (%) in Patients with Obstructive Sleep Apnea / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Snoring is the vibration sound of respiratory structures when air stream flows through the narrowed airway during sleep. In this study, we aimed to determine the clinical meaning of snoring time (%) of patients who have simple snoring or obstructive sleep apnea (OSA). MATERIALS AND METHODS: We performed a retrospective review of 240 cases of clinical data and polysomnography, which were diagnosed with either simple snoring (n=53) or OSA (n=187). Clinical data included anthropometric measurements such as body mass index, neck and waist circumference (WC), and wasit-hip ratio (WHR). Snoring time (%) was calculated as the total time of snoring per hour of sleep. RESULTS: In the female group, snoring time (%) increased in OSA compared to simple snoring, which showed a negative correlation with N3 (r=-0.395, p=0.002) and a positive correlation with the arousal index (r=0.39, p=0.003). Moreover, in females, snoring time (%) showed significant correlations with respiratory indexes: hypopnea index (p=0.008), apnea-hypopnea index (p=0.049), and lowest SpO₂ (p=0.003). WC and WHR showed significant correlations with snoring time (%) in both male and female. CONCLUSION: Snoring time (%) of females showed important clinical associations with sleep quality and respiratory index. Therefore, snoring may have an important role in the pathogenesis of OSA in females.

Do Helper T Cell Subtypes in Lymphocytic Thyroiditis Play a Role in the Antitumor Effect?

BACKGROUND: Papillary thyroid carcinoma (PTC) is frequently accompanied by lymphocytic thyroiditis (LT). Some reports claim that Hashimoto's thyroiditis (the clinical form of LT) enhances the likelihood of PTC; however, others suggest that LT has antitumor activity. This study was aimed to find out the relationship between the patterns of helper T cell (Th) cytokines in thyroid tissue of PTC with or without LT and the clinicopathological manifestation of PTC. METHODS: Fresh surgical samples of PTC with (13 cases) or without (10 cases) LT were used. The prognostic parameters (tumor size, extra-thyroidal extension of PTC, and lymph node metastasis) were analyzed. The mRNA levels of two subtypes of Th cytokines, Th1 (tumor necrosis factor α [TNF-α], interferon γ [IFN-γ ], and interleukin [IL] 2) and Th2 (IL-4 and IL-10), were analyzed. Because most PTC cases were microcarcinomas and recent cases without clinical follow-up, negative or faint p27 immunoreactivity was used as a surrogate marker for lymph node metastasis. RESULTS: PTC with LT cases showed significantly higher expression of TNF-α (p = .043), IFN-γ (p < .010), IL-4 (p = .015) than those without LT cases. Although the data were not statistically significant, all analyzed cytokines (except for IL-4) were highly expressed in the cases with higher expression of p27 surrogate marker. CONCLUSIONS: These results indicate that mixed Th1 (TNF-α, IFN-γ , and IL-2) and Th2 (IL-10) immunity might play a role in the antitumor effect in terms of lymph node metastasis.

Endoscopic Repair with Above and Below Technique of Recurrent Cerebrospinal Fluid Leak from the Posterior wall of Frontal Sinus: Case Report

Cerebrospinal fluid (CSF) rhinorrhea can be caused by head trauma, brain or sinus surgery, or neoplastic sinonasal disease. There are many diverse techniques for repairing skull base defects, and recently there has been a shift from using external approaches to endoscopic approaches. The reported success rate after endoscopic repair is 97%, but CSF rhinorrhea may recur in some cases. Recently, we witnessed one case of recurrent CSF rhinorrhea from the posterior wall of the frontal sinus after a traffic accident. The patient was a 48-year-old male and had recurrent CSF rhinorrhea, severe pneumocephalus and mental change even after a CSF leakage repair operation was performed by the neurosurgeon using the periosteal flap. We successfully treated recurrent frontal CSF rhinorrhea with fat graft and mucosal graft, using the above and below approach with the guidance of a navigation system.

Comparison of Modified Blair Incision and Modified Facelift Incision in Parotidectomy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Modified Blair incision (MBI) and Modified facelift incision (MFI) are mainly used for paroidectomy. MBI can provide a wide surgical view for parotidectomy. MFI was designed for better cosmesis by hiding the incision behind the auricle and hair line. This study was performed to evaluate surgical outcomes, functional and cosmetic results after parotidectomy using MBI and MFI. SUBJECTS AND METHOD: We retrospectively reviewed medical records of 120 patients who underwent parotidectomy from September 2005 to April 2012. Tumor characteristics, operative outcome, and cosmetic outcome according to incision method were investigated. Cosmetic satisfaction was assessed using a questionnaire 12-18 months after surgery. RESULTS: Tumor characteristics such as size, location and pathologic features did not differ between the two groups. The extent of parotidectomy, operation time, amout of drainage, and complications were also not different between the two groups. Cosmetic satisfaction was significantly supeior in the MFI group than that of the MBI group. CONCLUSION: MFI is superior to MBI for parotidectomy for having similar surgical outcome but better esthetical success compared to MBI.

Midterm Outcome of Femoral Artery Stenting and Factors Affecting Patency

PURPOSE: The purpose of this study was to evaluate the early and midterm results of superficial femoral artery (SFA) stenting with self-expanding nitinol stents and to identify the factors affecting patency. MATERIALS AND METHODS: SFA stenting was performed in 165 limbs of 117 patients from January 2009 to December 2013. Patients were followed-up for the first occurrence of occlusion or stenosis based on computed tomography and duplex scan results and a decrease in ankle brachial index of >15%. RESULTS: During the follow-up period (mean, 15.3+/-3.2 months), no early thrombotic reocclusions occurred within 30 days, but in-stent restenosis developed in 78 limbs. The primary patency rates at 6, 12, 18, and 24 months were 78%, 66%, 42%, and 22%, respectively, and the secondary patency rates were 85%, 72%, 58%, and 58%, respectively. TASC II C or D lesions, stent length >8 cm, number of patent tibial arteries and diabetes were significantly associated with reintervention. CONCLUSION: The midterm results of stenting for SFA occlusive disease were disappointing because the primary and secondary patency rates at two years were 22% and 58%, respectively. Reintervention after SFA stenting remains a major problem, particularly in patients with diabetes mellitus or long TASC II C or D lesions.

One Year Experience of Iliac Bifurcated Device for Aortoiliac Aneurysm in a Korean Single Center

One of the predominant methods for preserving the internal iliac artery (IIA) in aortoiliac aneurysms is to use an iliac bifurcated device (IBD). However, there are a few limitations to the use of IBD in Korea. Our study aims to present the technical aspects of these devices, and to provide a mid-term analysis of IBD. Since 2013, 4 IBDs were used in 4 patients, with a mean follow-up of 14 months (range, 6-22 months). A 100% technical success rate was achieved without mortality and morbidity in our cases. The mean procedural time was 176 min (range, 145-240 min), and the mean contrast dose used was 184 mL (range, 135-220 mL). Type I or III endoleaks and postoperative expansion of the aneurysms weren't observed. Our cases demonstrates that IBD is a relatively safe repair method of aortoiliac aneurysms with preservation of the IIAs. However, a longer follow-up is needed to review the midterm results.

Role of Cochlear Microphonic in Newborn Hearing Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cochlear microphonic (CM) is an electrical potential generated by outer hair cells in response to acoustic stimulation. The aim of this study is to evaluate the significance of CM in neonatal hearing loss. SUBJECTS AND METHOD: From April 2013 to April 2014, 64 neonates hospitalized in neonatal intensive care unit were enrolled. Subjects underwent transient evoked otoacoustic emission (TEOAE), auditory brain stem response (ABR) and CM. We analyzed the results of hearing tests and the correlation between CM and the other test modalities. RESULTS: Ninety two ears showed normal ABR waves whereas the other 36 ears had abnormal ABR. There were two neonates who were suspected of auditory neuropathy because of the presence of TEOAE and CM. Among 14 ears who showed abnormal OAE results, 12 ears (86%) were identified as having CM. The amplitudes of CMs were correlated with the reproducibility of TEOAE (p<0.005). Between the ears with positive TEOAE and others with negative TEOAE, the amplitudes of CMs were significantly different (p<0.005). CONCLUSION: Many ears were identified with the presence of CM without TEOAE response because of the the vulnerability of OAE from middle ear status and environment. We suppose that CM might provide information on outer hair cell function to complement the OAE in neonatal hearing test.

All-Trans Retinoic Acid Has a Potential Therapeutic Role for Diabetic Nephropathy

PURPOSE: The aim of this study was to examine the effects of all-trans retinoic acid (ATRA) on diabetic nephropathy. MATERIALS AND METHODS: We measured amounts of urinary albumin excretion (UAE) after administrating ATRA to Otsuka Long-Evans Tokushima Fatty (OLETF) rats. In order to understand the mechanism of action for ATRA, we administrated ATRA to examine its inhibitory action on the production of transforming growth factor-beta1 (TGF-beta1), protein kinase C (PKC), and reactive oxidative stress (ROS) in cultured rat mesangial cells (RMCs). RESULTS: After 16 weeks of treatment, UAE was lower in the ATRA-treated OLETF rats than in the non-treated OLETF rats (0.07+/-0.03 mg/mgCr vs. 0.17+/-0.15 mg/mgCr, p<0.01). After incubation of RMCs in media containing 30 or 5 mM of glucose, treatment with ATRA showed time- and dose-dependent decreases in TGF-beta1 levels and ROS. Moreover, ATRA treatment showed a dose-dependent decrease in PKC expression. CONCLUSION: ATRA treatment suppressed UAE and TGF-beta1 synthesis, which was mediated by significant reductions in PKC activity and ROS production. Our results suggest that ATRA has a potential therapeutic role for diabetic nephropathy.

Voice Outcome and Quality of Life after Laser Cordectomy in Glottic Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Laser cordectomy is considered one of the best techniques for the treatment of early stage glottic cancer. But voice outcome and quality of life (QOL) after laser cordectomy is controversial. The aim of this study is to evaluate the voice outcome after laser cordectomy in glottic cancer and its association to QOL. SUBJECTS AND METHOD: 43 patients who underwent laser cordectomy from January 2002 to December 2008 were enrolled in this study. We evaluated the objective and subjective voice outcomes using acoustic analysis, aerodynamic study and voice handicap index (VHI). We also assessed QOL using EORTC QLQ-C30/H&N35 questionnaire. We compared the voice outcome according to the type of laser cordectomy and analyzed correlation between voice outcome and QOL. RESULTS: Harmonic to noise ratio, maximum phonation time and VHI of patients treated with Types I, II cordectomy was significantly improved after operation. Functional VHI after Types I, II cordectomy was significantly lower than Types III-VI cordectomy. The postoperative QOL score of glottic cancer patients were not statistically different between Type I, II and Type III-VI cordectomy. QOL score had a positive correlation with postoperative VHI. CONCLUSION: Objective and subjective voice outcomes after laser cordectomy showed favorable results, especially in patients who were treated with Types I, II laser cordectomy. QOL scores were correlated with VHI scores, but not with acoustic parameters.

Endoscopic Frontal Sinus Surgery / 대한이비인후과학회지

Surgery on the frontal sinus or frontal recess remains a challenge for rhinologist because of its variability and complex anatomy. Its location, relatively complex and narrow frontal recess also make visualization difficult and predispose it to stenosis. Significantly, serious complications are possible due to the anterior ethmoidal artery, orbit and anterior cranial fossa. An understanding of frontal sinus and frontal recess anatomy is essential to perform endoscopic frontal sinus surgery. This paper examines frontal sinus anatomy and then variable procedures of endoscopic frontal sinus surgery. The selection of less invasive procedure as possible after assessment of the patient's history, diagnostic endoscopy, and the CT scan makes successful endoscopic treatment of frontal sinus diseases.

Association Between Blood Sugar Level, Psychological Impact, and Emotional Symptoms in Patients Newly Diagnosed with Diabetes / 임상당뇨병

As the duration of diabetes mellitus (DM) increases, the risk of complications increases and the prevalence of depression becomes higher. Most studies on depression in Korean patients with DM have focused on a point 5-10 years after diagnosis, and there has not been much data reported regarding the early stages of DM, including newly developed DM. In this study, we examined whether blood glucose levels could be associated with emotional symptoms such as depression (DS) and anxiety (AS) in patients newly diagnosed with DM. Serum glucose and HbA1c were measured in 89 patients with DM. The Impact of Event Scale (IES) was used to investigate the extent of the psychological impact of a diagnosis of DM. The IES comprises four elements: hyperarousal, intrusiveness, avoidance, and sleep problems. DS and AS were investigated using the Hospital Anxiety and Depression Scales. DS was observed in 32 patients (36%) and AS was observed in 21 patients (23.6%), indicating a higher prevalence of DS and AS than in the general population. There was an inverse correlation between HbA1c and DS (Pearson's correlation coefficient: R = -0.227; P = 0.035), but no correlation was found for AS. The four elements of the IES had significant correlations with DS and AS. Logistic regression analysis showed that sleep problems (OR = 1.437) and HbA1c (OR = 0.51) were associated with DS, but only intrusiveness (OR = 0.629) showed a correlation with AS. In patients newly diagnosed with DM, DS is associated with sleep problems and low HbA1c levels. Emotional symptoms should be considered as part of glucose control, and efforts to mitigate psychological stress during the initial period of diabetes management should be made.

Peripheral Primitive Neuroectodermal Tumor with Osseous Component of the Small Bowel Mesentery: A Case Study

A case of peripheral primitive neuroectodermal tumor of the small bowel mesentery with osseous component is reported. A 23-year-old man was admitted to our hospital because of acute severe abdominal pain. Abdominal computed tomography revealed a large solid and cystic, oval shaped mass, measuring 11.0x6.0 cm in the pelvic cavity. Histologically the resected lesion consisted of sheets of undifferentiated small round cells forming Homer-Wright rosettes and perivascular pseudorosettes, and showed areas of osteoid and bone formation. Immunohistochemical studies revealed that tumor cells expressed positivity against CD99 (MIC2), CD57, neuron-specific enolase, and vimentin. Fluorescence in situ hybridization study revealed Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangement on chromosome 22q12. To the authors' knowledge this is the first documentation of a peripheral neuroectodermal tumor with osteoid and bone formation of the small bowel mesentery.