Multivariate analysis of carcinogenic equivalence (CEQ) to characterize carcinogenic VOC emissions in a typical petrochemical industrial park in Taiwan.

Large industrial emissions of volatile organic compounds (VOCs) from the petrochemical industry are a critical concern due to their potential carcinogenicity. VOC emissions vary in composition depending on the source and occur in mixtures containing compounds with varying degrees of toxicity. We proposed the use of carcinogenic equivalence (CEQ) and multivariate analysis to identify the major contributors to the carcinogenicity of VOC emissions. This method weights the carcinogenicity of each VOC by using a ratio of its cancer slope factor to that of benzene, providing a carcinogenic equivalence factor (CEF) for each VOC. We strategically selected a petrochemical industrial park in southern Taiwan that embodies the industry's comprehensive nature and serves as a representative example. The CEQs of different emission sources in three years were analyzed and assessed using principal component analysis (PCA) to characterize the major contributing sectors, vendors, sources, and species for the carcinogenicity of VOC emissions. Results showed that while the study site exhibited a 20.7 % (259.8 t) decrease in total VOC emissions in three years, the total CEQ emission only decreased by 4.5 % (15.9 t), highlighting a potential shift in the emitted VOC composition towards more carcinogenic compounds. By calculating CEQ followed by PCA, the important carcinogenic VOC emission sources and key compounds were identified. More importantly, the study compared three approaches: CEQ followed by PCA, PCA followed by CEQ, and PCA only. While the latter two methods prioritized sources based on emission quantities, potentially overlooking less abundant but highly carcinogenic compounds, the CEQ-first approach effectively identified vendors and sources with the most concerning cancer risks. This distinction underscores the importance of selecting the appropriate analysis method based on the desired focus. Our study highlighted how prioritizing CEQ within the analysis framework empowered the development of precise control measures that address the most carcinogenic VOC sources.

Modeling of the Spatial Distribution of Forest Carbon Storage in a Tropical/Subtropical Island with Multiple Ecozones.

Visual data on the geographic distribution of carbon storage help policy makers to formulate countermeasures for global warming. However, Taiwan, as an island showing diversity in climate and topography, had lacked valid visual data on the distribution of forest carbon storage between the last two forest surveys (1993-2015). This study established a model to estimate and illustrate the distribution of forest carbon storage. This model uses land use, stand morphology, and carbon conversion coefficient databases accordingly for 51 types of major forests in Taiwan. An estimation in 2006 was conducted and shows an overall carbon storage of 165.65 Mt C, with forest carbon storage per unit area of 71.56 t C ha-1, where natural forests and plantations respectively contributed 114.15 Mt C (68.9%) and 51.50 Mt C (31.1%). By assuming no change in land use type, the carbon sequestration from 2006 to 2007 by the 51 forest types was estimated to be 5.21 Mt C yr-1 using historical tree growth and mortality rates. The result reflects the reality of the land use status and the events of coverage shifting with time by combining the two forest surveys in Taiwan.

The Influences of Pore Blockage by Natural Organic Matter and Pore Dimension Tuning on Pharmaceutical Adsorption onto GO-Fe3O4.

The ubiquitous presence of pharmaceutical pollution in the environment and its adverse impacts on public health and aquatic ecosystems have recently attracted increasing attention. Graphene oxide coated with magnetite (GO-Fe3O4) is effective at removing pharmaceuticals in water by adsorption. However, the myriad compositions in real water are known to adversely impact the adsorption performance. One objective of this study was to investigate the influence of pore blockage by natural organic matter (NOM) with different sizes on pharmaceutical adsorption onto GO-Fe3O4. Meanwhile, the feasibility of pore dimension tuning of GO-Fe3O4 for selective adsorption of pharmaceuticals with different structural characteristics was explored. It was shown in the batch experiments that the adsorbed pharmaceutical concentrations onto GO-Fe3O4 were significantly affected (dropped by 2-86%) by NOM that had size ranges similar to the pore dimensions of GO-Fe3O4, as the impact was enhanced when the adsorption occurred at acidic pHs (e.g., pH 3). Specific surface areas, zeta potentials, pore volumes, and pore-size distributions of GO-Fe3O4 were influenced by the Fe content forming different-sized Fe3O4 between GO layers. Low Fe contents in GO-Fe3O4 increased the formation of nano-sized pores (2.0-12.5 nm) that were efficient in the adsorption of pharmaceuticals with low molecular weights (e.g., 129 kDa) or planar structures via size discrimination or inter-planar π-π interaction, respectively. As excess larger-sized pores (e.g., >50 nm) were formed on the surface of GO-Fe3O4 due to higher Fe contents, pharmaceuticals with larger molecular weights (e.g., 296 kDa) or those removed by electrostatic attraction between the adsorbate and adsorbent dominated on the GO-Fe3O4 surface. Given these observations, the surface characteristics of GO-Fe3O4 were alterable to selectively remove different pharmaceuticals in water by adsorption, and the critical factors determining the adsorption performance were discussed. These findings provide useful views on the feasibility of treating pharmaceutical wastewater, recycling valuable pharmaceuticals, or removing those with risks to public health and ecosystems.

The effect of metformin and drinking water quality variation on haloacetamide formation during chlor(am)ination of acetaminophen.

Acetaminophen (Apap) is widely used and is known to form toxic haloacetamides (HAcAms) during chlorination. Metformin (Met) is a typical medication with usage much higher than that of Apap and its ubiquitous presence in the environment is known. The objective of this study was to investigate the effects of Met which contains multiple amino groups potentially joining reactions and different chlorination methods on HAcAm formation from Apap. In addition, a major drinking water treatment plant (DWTP) using the largest river in southern Taiwan was sampled to study the influence of Apap in a DWTP on the HAcAm formation. Results showed increasing dichloroacetamide (DCAcAm) molar yields of Apap at a Cl/Apap molar ratio of 5 during chlorination (0.15%) and two-step chlorination (0.03%). HAcAms were formed by the chlorine substitution of hydrogen on the methyl group in Apap followed by the cleavage of the bonding between nitrogen and aromatic. While a high Cl/Apap ratio during chlorination led to reactions between chlorine and HAcAms formed decreasing the HAcAm yields, the two-step chlorination further reduced the HAcAm formation during chlorination by a factor of 1.8-8.2. However, Met which limitedly formed HAcAms increased the DCAcAm yields of Apap by 228% at high chlorine dosages during chlorination and by 244% during two-step chlorination. In the DWTP, trichloroacetamide (TCAcAm) formation was important. The formation was positively correlated with NH4+, dissolved organic carbon (DOC), and specific ultraviolet absorbance (SUVA). DCAcAm dominated in the presence of Apap. The DCAcAm molar yields were 0.17%-0.27% and 0.08%-0.21% in the wet and dry seasons, respectively. The HAcAm yields of Apap in the DWTP were limitedly changed between different locations and seasons. Apap could be one important cause for HAcAm formation in a DWTP, as the presence of other pharmaceuticals such as Met possibly worsens the situation in chlorine applications.

Variations of N concentrations and microbial community in the start-up of anammox using anaerobic heterotrophic sludge: Influence of a long reaction-phase time and comparison of the efficiencies of attached-versus suspended-growth cultures.

Anaerobic sludge was capable of producing anaerobic ammonium oxidation (anammox) cultures. However, the low activity of anammox bacteria in the seed sludge often led to a long time for stable anammox to initiate. The objective of this study was to investigate the influence of an extended reaction-phase time in the sequencing batch reactor (SBR) on the rapid startup of anaerobic ammonium oxidation (anammox) using anaerobic heterotrophic bacteria as the seed sludge. After the startup, suspended and attached bacteria in anammox were separately analyzed for comparison. The variations of nitrogen concentrations and shifts of the microbial community structures were studied. The results showed that anammox occurred after a long reaction-phase time in the SBR with the efficient removals of NH4+ (96.4%) and NO2- (99.8%). The effective NO2- treatment before anammox startup was attributable to inevitable denitrification or dissimilatory nitrate reduction (e.g., Denitratisoma). The occurrence of anammox was supported by the anammox stoichiometry, bacteria diversity variation, and principal component analysis. The overall nitrogen removal rate (NRR) and nitrogen removal efficiency (NRE) was 0.07 kg/m3-d and 92.8%, respectively. The relative molar quantities of NH4+ and NO2- removed as well as N2 and NO3- formed were 1(1):1.29(1.32):1.45(1.02):0.15(0.26), as the numbers in the parentheses represent the theoretical values. Denitratisoma and Desulfatiglans dominated in the seed sludge, whereas Candidatus_Jettenia abundances were significantly higher in anammox attached- (26.0%) and suspended-growth cultures (14.5%). Fifty-three genera were simultaneously identified in all samples, suggesting their importance in the startup of anammox from anaerobic sludge. Candidatus_Jettenia was observed to be more associated with the growth of anammox biofilm (the abundances were 26.0% and 14.5% in attached- and suspended-growth cultures, respectively) and supported the fine nitrogen removal performance in the attached-growth cultures.

Generating large out-of-plane piezoelectric properties of atomically thin MoS2via defect engineering.

We calculated the piezoelectric properties of asymmetrically defected MoS2 using density functional theory. By creating uneven numbers of defects on either side of two-dimensional MoS2, the out-of-plane centrosymmetry of the charge distribution is clearly broken, and the out-of-plane piezoelectric response is induced. The largest out-of-plane piezoelectric response is associated with the highest defect ratio for MoS2 to be semiconducting. We calculated the critical defect density of the metal-insulator transition of the asymmetrically defected MoS2 to be 9.90 × 1014 cm-2 and chemical formula MoS1.22. The d33 of the multilayer of optimally defected MoS2 is found to be greater than those of AlN and ZnO, and in the same order of magnitude as lead zirconate titanate. All two-dimensional transition metal dichalcogenides can in principle be fabricated as piezoelectric with this approach. The required defect engineering is readily available with various types of ion irradiation or plasma treatment. By controlling the dose of the ion, the defect ratio and hence the piezoelectricity can be tuned. Such asymmetrically defected transition metal dichalcogenides can easily be integrated into two-dimensional transition metal dichalcogenide based devices, which is hard for conventional piezoelectric thin films to rival.

Studies of zwitterionic sulfobetaine functionalized polypropylene surface with or without polyethylene glycol spacer: surface characterization, antibacterial adhesion, and platelet compatibility evaluation.

Microbial adhesion reduction as well as platelet compatibility improvement have been suggested as the key requirements for developing blood-contacting synthetic biomaterials. Surface grafting of hydrophilic polyethylene glycol chains or alkyl chains with zwitterionic terminal ends has been proposed for reducing microbial or platelet adhesion. Nonetheless, none has been reported to incorporate both polyethylene glycol and zwitterionic terminal functionality on the same surface-grafted alkyl chain. In this investigation, a novel surface modification scheme was reported for grafting zwitterionic alkyl chains with or without polyethylene glycol as the spacer. It was noted the bacterial adhesion reduction capability on the zwitterionic modified surface was dependent upon the use of polyethylene glycol spacer or not and the strain of microbe tested. Besides, the zwitterionic modified ones all showed greater antimicrobial adhesion capability than the surface modified with polyethylene glycol alone. On the other hand, significantly reduced platelet adhesion and activation were found, but with no statistical differences noted among the polyethylene glycol-modified surface and zwitterionic ones, with or without polyethylene glycol spacer. These suggested that the use of polyethylene glycol spacer on the zwitterionic terminated surface could further enhance the antimicrobial adhesion against gram-negative bacterial while still keeping its platelet compatibility.

Investigation of the Capacitance-Voltage Electrical Characteristics of Thin-Film Transistors Caused by Hydrogen Diffusion under Negative Bias Stress in a Moist Environment.

In this study, the impact of moisture on the electrical characteristics of an amorphous In-Ga-Zn-O thin-film transistor (a-IGZO TFT) was investigated. In commercial applications of such TFTs, high stability and quality performance in humid environments are essential. During TFT operation under ambient moisture, the electrolysis of water molecules occurs via the tip electric field effect. Hydrogen diffuses from the etch-stop layer or back-channel into the main channel under a negative electric field. The hydrogen atoms act as shallow donors (which causes the carrier concentration in the channel to rise), causing the threshold voltage (VTH) to shift in the negative direction. Hydrogen diffusion from the overlap of the source/drain and gate electrodes to the channel center caused by the tip electric field induces a significant barrier lowering and VTH shifts in a short-channel device. However, under negative bias stress (NBS) in ambient moisture, the negative VTH shift is more obvious in short- than in long-channel devices, indicating suppressed hydrogen diffusion in long-channel devices. This is attributed to the electrolysis of water by the tip electric field at the source, drain, and gate electrodes, which causes hydrogen to diffuse to the center of the channel. Here, a novel physical model of the capacitance-voltage (C-V) electrical property changes under ambient moisture is proposed, based on the early appearance of abnormalities in the C-V measurements. The electrolysis of water caused by the tip electric field and electrical abnormalities caused by hydrogen diffusion into the a-IGZO active layer are explained by this model. A secondary-ion mass spectrometry analysis shows that hydrogen content in the channel generally increases under NBS in ambient moisture. The degradation behavior due to moisture in a-IGZO is clarified. Thus, inhibiting the tip electric field may benefit future flexible-display and gas-sensing applications.

Influence of emulsified biodiesel on the emission and health risk of polycyclic aromatic hydrocarbons in the vapor and particulate phases during engine combustion.

Biofuel is a renewable energy source for transportation. Given the toxicity associated with particulate polycyclic aromatic hydrocarbons (PAHs) is not fully understood, investigating the difference of adverse health risks posed between vapor and particulate PAH emissions from biodiesel-fueled engine combustion was the objective of this study. Three different fuel types, including typical diesel, emulsified diesel with a water fraction from 10 to 19% (v/v), and emulsified biodiesel with water (10%) and biofuel fractions from 10 to 40% (v/v), were studied. The fugacity model and risk assessment were conducted to predict the health risks when different fuels were used. In the results, the addition of water and biofuel elevated and reduced the total PAH emissions in the exhausts, respectively. After the emission, chrysene and benzo(a)anthracene were two dominant carcinogenic species in the environment. The excess cancer risk of the PAH emission significantly decreased (e.g., up to two orders of magnitude) while the emulsified biodiesel was applied, with limiting the formation of benzo(a)pyrene being the explanation. The PAH emissions with molecular weights ranging from 166 to 255 g/mol were significantly different between the vapor and particulate phases during the emulsified biodiesel combustion (p < 0.01). From the viewpoint of cancer risk, the contribution posed by the particulate PAHs was significantly greater than those by the vapor PAHs (e.g., from 54% (benzo(a)pyrene) to 76% (benzo(b)fluoranthene)). Benzo(a)pyrene and chrysene represent the species with the highest and lowest risks, respectively. The multi-ringed PAHs with four or five rings were more indicative of potential cancer risk posed by the PAHs associated with particulate matters during combustion of the emulsified biodiesel.

Cyclical Annealing Technique To Enhance Reliability of Amorphous Metal Oxide Thin Film Transistors.

This study introduces a cyclical annealing technique that enhances the reliability of amorphous indium-gallium-zinc-oxide (a-IGZO) via-type structure thin film transistors (TFTs). By utilizing this treatment, negative gate-bias illumination stress (NBIS)-induced instabilities can be effectively alleviated. The cyclical annealing provides several cooling steps, which are exothermic processes that can form stronger ionic bonds. An additional advantage is that the total annealing time is much shorter than when using conventional long-term annealing. With the use of cyclical annealing, the reliability of the a-IGZO can be effectively optimized, and the shorter process time can increase fabrication efficiency.

Oral malignant acanthosis nigricans associated with endometrial adenocarcinoma.

We report a 59-year-old patient with malignant acanthosis nigricans associated with metastasis of endometrial carcinoma. The patient presented papillomatosis lesions that appeared to be benign on multiple skins of body folds, particularly on lips. The lesions in lips and axilla had histological characteristic appearances of acanthosis nigricans, while the masses in abdomen and pelvis were metastasis endometrial adenocarcinoma. The article highlights the importance of biopsy and histopathological diagnosis in presumed benign lesions and the role of doctors in screening for body internal tumors.

[Application of CAD/CAM technique in three-dimensional reconstruction of zygomatic complex defect].

OBJECTIVE: To evaluate the efficacy of computer-aided design and computer-aided manufacturing (CAD/CAM) technique in reconstruction of zygomatic complex defect. METHODS: Three-dimensional computed tomography (3D-CT) and rapid prototyping (RP) techniques were applied to produce facsimile models in 13 patients with zygomatic complex defects resulted from trauma or tumor ablation. The zygomatic complex defect was reconstructed using a mirroring technique by CAD/CAM. Titanium mesh was prefabricated on individual facsimile models and combined with autologous bone graft and pedicled buccal fat pad flap for reconstruction. RESULTS: The measuring data of zygomatic complex defect between facsimile model and intraoperative findings was extremely consistent. The prefabrication of reconstructive titanium mesh was matched with zygomatic complex defect in the surgery. The postoperative 3D-CT image demonstrated the symmetry of reconstructed zygomatic complex. The functional recovery and facial contours were satisfactory in all cases. CONCLUSION: The application of CAD/CAM technique can simulate the surgery procedures accurately, which contributes to shorten the actual operative time. RP techniques can reconstruct the facial contours symmetry and recover the function of zygomatic complex defect.

Deep lingual arterial chemoembolization of tongue carcinoma with microcapsuled anticancer drug.

OBJECTIVE: Microcapsule chemoembolism is a promising treatment of tumors. We describe a deep lingual arterial embolization of tongue carcinoma with microcapsuled carboplatinum. METHODS: Lingual artery cast specimens from cadavers were microscopically examined, and 78 patients with tongue cancer were recruited and treated with the deep lingual arterial embolization therapy. RESULTS: Microcapsule embolism occurred approximately at the fifth or sixth level of the deep lingual artery branches. The five-year survival rate was 88.5% (69 out of 78), and the ten-year survival rate 52.6% (41 out of 78). CONCLUSION: The deep lingual arterial embolization of tongue carcinoma with microcapsuled carboplatinum is an effective therapy to treat carcinoma in mid-margin or mid-body of the tongue.

[The application of three dimensional craniomaxillofacial model in the restoration of mandibular bone defects with vascularized fibular autograft].

OBJECTIVE: To evaluate the effect of applying the three dimensional craniomaxillofacial model technique in the restoration of mandibular defects with vascularized fibular autograft. METHODS: Three dimensional craniomaxillofacial models of 24 patients with mandibular defects were achieved by CT scan and rapid prototype technique. Surgery simulation and individual prefabricated titanium board were designed on the models. Vascularized fibular autograft was obtained, remodeled with titanium implant based upon preoperative surgery simulation, and implanted into the site with mandibular defect. RESULTS: By using three-dimensional craniomaxillofacial model, all fibular flaps survived without complication in all 24 patients. Bony union was achieved between the implanted fibula and the mandible. First intention of the wound was achieved. The appearance of the mandibular bone was well recovered shown by 3-dimensional CT scan. CONCLUSION: Based upon the preoperative surgery simulation with three dimensional craniomaxillofacial model, vascularized fibular autograft has many advantages for mandible reconstruction and represents the first choice for the head and neck surgeon.

[Extraarticular diffuse pigmented villonodular synovitis of the temporomandibular joint: report of one case and review of the literature].

Diffuse pigmented villonodular synovitis (PVNS) in the temporomandibular joint (TMJ) is distinctly rare. This article reported a case of extra-articular type of PVNS of the TMJ, and reviewed the previously reported cases in the literature. It is concluded that PVNS can be diagnosed by characteristic MRI finding, wide local excision including a total synovectomy and postoperative radiotherapy should be adopted.

[Reconstruction of maxillary defect by prefabricated titanium mesh combined with pedicled buccal fat pad flap and bone autograft].

OBJECTIVE: To introduce individualized 3-dimensional (3-D) reconstruction of maxillary defect by prefabricated titanium mesh combined with pedicled buccal fat pad flap (PBFPF) and bone autograft. METHODS: Since May, 2001, 16 patients with maxillary defect resulted from tumor or trauma were treated. The 3-D models were created through 3-D CT and rapid prototype technique. The maxilla on the unaffected side was copied to the affected side by CAD/CAM. Then the titanium mesh was prefabricated accurately on the 3-D model. The PBFPF served as lining of the titanium mesh and the autogenous bone graft was used to reconstruct the shape and function of maxilla. RESULTS: The duration of follow-up was 6 to 36 months. All the wounds healed primarily with good facial symmetry. No food reflux to nasal cavity was observed. The dentitions in 8 of 16 cases were restored with good function by removable partial denture. They could have normal diet and were articulate. Nasopharyngoscopy showed normal tissue lining of the titanium mesh 5-12 months after operation in 3 cases. CONCLUSIONS: Satisfactory aesthetic and functional result can be achieved with this 3-D reconstruction method for maxilla defect. The PBFPF was insert better titanium mesh and mucous of maxilla sinus to avoid exposure of titanium mesh. The fat pad flap with blood supply promotes wound healing and helps partially restoring the function of the maxillary sinus.

[Relative quantification of cytokeratin 19 transcription in oral squamous cell carcinoma tissues by fluorescent quantitive real-time RT-PCR].

OBJECTIVE: To investigate the relative quantification of cytokeratin 19 transcription in oral squamous cell carcinoma tissues by fluorescent quantitive real-time reverse transcription-polymerase chain reaction ((RT-PCR). METHODS: CK19mRNA level was detected by fluorescent quantitive real-time RT-PCR in cancerous and para-cancerous tissues from 31 oral squamous cell carcinoma patients. According to the 2(-DeltaDeltaCt) equation, the relative quantification fold of CK19mRNA level was calculated in cancerous tissues compared with para-cancerous tissues. RESULTS: CK19mRNA levels in cancerous tissues were 2.21 folds higher than those in para-cancerous tissues, and the amplicon was specific. CK19mRNA level in cancerous tissue correlated significantly with pathological differentiation degree, the poorer the differentiation was, the higher the CK19mRNA level became. CONCLUSIONS: Fluorescent quantitive real-time RT-PCR is accurate and reliable in the detection of relative quantification of CK19 transcription in oral squamous cell carcinoma tissues.

Increased levels of CK19 mRNA in oral squamous cell carcinoma tissue detected by relative quantification with real-time polymerase chain reaction.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral and maxillofacial region and has a poor prognosis. Cytokeratin 19 (CK19) is a component of cytoskeleton protein. Previous studies have reported abnormal expression of CK19 protein in OSCC tissue. This study is to investigate the quantitative level of CK19 gene transcript in OSCC tissue as well as its clinical significance. Thirty-one OSCC patients (26 males and 5 females) took part in the present study, aged 34-78 years (mean 58.2 years). The level of CK19 mRNA was detected using fluorescent quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) in cancerous and paracancerous tissues. The relative quantification in cancerous tissue compared with paracancerous tissue was calculated using the 2(-DeltaDeltaCt) equation. The level of CK19 mRNA in cancerous tissue from OSCC patients was 2.21-fold higher than that in paracancerous tissue (P=0.020), and the amplicon was specific without genomic DNA contamination. The level of CK19 mRNA correlated significantly with the pathological differentiation grade of OSCC tissue (P=0.025), with poorer differentiation indicating a higher level of CK19 mRNA. These results suggest that fluorescent quantitative real-time RT-PCR is accurate and reliable for the detection of CK19 gene transcript levels in OSCC tissue. The level of CK19 mRNA was increased in OSCC tissue, and this was significantly correlated with the pathological differentiation grade.

[The effect of artificial bone implantation in cleft palate on the development of maxilla].

OBJECTIVE: To research the influence of palate bone implantation to the growth of maxilla in three dimensional direction. METHODS: 40 patients of congenital cleft palate type II with palate board damage were stochastically divide into the comparison group and bone planted group. In bone planted group, HA-Bone cement was used to repair palate tabular damage. All patients are 16 full year old, cephalometric radiograph and tooth cast model were measured and contrast analysis was applied. RESULTS: Planted bone group and the comparison group does not have the significance difference in both the maxilla length and maxilla hightness( P > 0.05); But there was significance difference in the width of post-part of the maxilla (P < 0.05). CONCLUSIONS: It could promote the growth of maxilla width in use of bone implantation, that advocated the bone repair in the sequence treatment process in cases of the hard palate bone damage.

[Langerhans' cell histiocytosis of the mandible in infant: report of one case].

Langerhans' cell histiocytosis of the mandible is a rare disease in infant. This article reported a case of Langerhans' cell histiocytosis of mandible in a 2-year old female child. The clinical manifestation, radiographic characteristics, pathologic diagnosis, differential diagnosis and treatment were discussed. It is concluded that Langerhans' cell histiocytosis of the mandible in infant is rare without typical clinical manifestation and radiographic characteristics; final diagnosis is based on pathological examination with the characteristic hyperplasia of Langerhans' cell; immunohistochemistry examination of S-100 and CD1a are useful for diagnosis and differential diagnosis. Surgical resection with close postoperative follow-up is suggested as the main treatment for this disease.