The Roles of Vascular Endothelial Growth Factor, Angiostatin, and Endostatin in Nasal Polyp Development

Background and Objectives@#Microvascular remodeling and angiogenesis are elements of tissue remodeling characteristic of chronic inflammatory diseases, including nasal polyps (NPs). Angiogenesis reflects the balance between the actions of pro- and anti-angiogenic factors. Many pro-angiogenic factors are known, including vascular endothelial growth factor (VEGF). A number of anti-angiogenic factors (e.g., angiostatin and endostatin) also has been identified. Our objective was to assess the roles of VEGF, angiostatin, and endostatin in NP development. @*Methods@#The expression levels of VEGF, angiostatin, and endostatin were measured in NPs harvested during endoscopic endonasal surgery and compared with those in inferior turbinate mucosa (control) samples acquired from patients with hypertrophic rhinitis without allergy. Western blotting and immunohistochemical staining were used to analyze all samples. @*Results@#The levels of VEGF and angiostatin were significantly higher in the NP subjects than in the controls. Neither the VEGF/angiostatin ratio nor the endostatin level differed significantly between the two groups. However, the VEGF/endostatin ratio was significantly higher in the NP than in the control group. Both the NP and control tissues were diffusely immunoreactive for VEGF, angiostatin, and endostatin. @*Conclusion@#NP-associated hypoxia can elevate angiostatin level; moreover, an imbalance in the VEGF/endostatin ratio can contribute to NP formation.

A Case of Follicular Lymphoma of Sphenoid Sinus and Orbit / 대한이비인후과학회지

Malignant lymphoma is a tumor of the immune system. It mainly occurs in the lymph node, but it can also originate from extranodal organs such as the gastrointestinal tract, salivary gland and the sinonasal tract. A primary malignant lymphoma in the paranasal sinuses is rare and usually occurs in the maxillary or ethmoid sinus. The sphenoid sinus is a rare primary site for extranodal lymphomas. Moreover, follicular lymphoma involving paranasal sinuses rarely occurs. Recently, we experienced a patient who complained of facial swelling, exophthalmos, reduced visual acuity, and diplopia for a month, and she was diagnosed with follicular lymphoma of the sphenoid sinus and orbit. Here we report a rare case of follicular lymphoma of the sphenoid sinus and orbit, along with a literature review.

Validation of Simultaneous Endoscopic Sinus Surgery and Transsphenoidal Surgery in Patients with Chronic Rhinosinusitis and Pituitary Tumors / 대한이비인후과학회지

Background and Objectives@#Transsphenoidal (TS) surgery for removal of pituitary lesions has become popular with improvements in diagnostic and treatment modalities, as well as endonasal and endoscopic methods, resulting in reduced complications. Rhinosinusitis (RS) is considered a risk factor for postoperative intracranial infections. Previously, we showed that concurrent TS surgery and endoscopic sinus surgery (ESS) yielded a favorable outcome in cases with pituitary lesions and RS. However, there seems to be a lack of consensus in performing simultaneous TS and ESS for patients with a pituitary lesion and RS. We would like to validate the feasibility of performing two operations concurrently.Subjects and Method We reviewed the medical records of 13 patients who underwent simultaneous TS surgery and ESS between 2007 and 2016. One patient underwent concurrent TS surgery and ESS twice due to the regrowth of pituitary macroadenoma and recurrence of RS. @*Results@#There were only four minor nasal complications during the postoperative period, which were controlled with conservative treatment. Only one patient exhibited postoperative cerebrospinal fluid leakage and no patients experienced intracranial complications. @*Conclusion@#This study shows that it might be better to treat patients with pituitary lesion and RS simultaneously. Also, further studies with large cases would be necessary to manage these patients without intracranial complications.

A Case of Myeloid Sarcoma in the Nasal Cavity Occurred in the Patient with Leukemic Transformation in Myelodysplastic Syndrome / 대한이비인후과학회지

Myeloid sarcoma is characterized by the presence of myeloid blasts at an extramedullar site that disrupts the normal architecture of the organ. Many of these cases are associated with acute myeloid leukemia, chronic myeloid leukemia, myelodysplastic syndrome, or occur in de novo. It occurs most commonly in skin, lymph node, gastrointestinal tract, bone, soft tissue but, rarely in head and neck; especially in nasal cavity. Therefore, it is often misdiagnosed as a different disease: most commonly as lymphoma. Here we report a rare case of myeloid sarcoma in the nasal cavity that occurred in a patient with leukemic transformation with myelodysplastic syndrome, provided with literature review.

A Case of Papillary Squamous Cell Carcinoma Which Associated with Inverted Papilloma in Sinonasal Cavity / 대한이비인후과학회지

According to the classification of World Health Organization, papillary squamous cell carcinoma is a variant of squamous cell carcinoma. This is a malignancy rarely found in the upper aerodigestive tract, especially in the sinonasal tract. We experienced a case, in which a 50-year-old man had papillary squamous cell carcinoma on his right nasal cavity, accompanied with inverted papilloma and fungiform papilloma. They were resected via endoscopic and Caldwell-Luc's approach. After the operation, the patient was treated with radiotherapy for 7 weeks, and has been disease-free for two years. We present the clinical characteristics, pathology, treatment, and prognosis of the tumor with a review of the literature.

Hairy Polyp in Nasal Vestibule

Hairy polyps are rare congenital benign masses of the head and neck. They mainly occur in the nasopharynx and oropharynx. This paper reports a 12-month-old female patient who had a 0.5-cm sausage-shaped mass in the left nasal vestibule with nasal obstruction and habitual nose-picking. This lesion was surgically removed with no complications under monitored anesthesia. There was no evidence of recurrence through 24 months. To the best our knowledge, this is the first English literature report of a patient with a hairy polyp arising from a nasal vestibule.

Dexamethasone Induces Apoptosis of Nasal Polyp-Derived Tissue Cultures Through JNK and p38 MAPK Activation

OBJECTIVES: Glucocorticoids, such as dexamethasone (DEX), increase apoptosis in a variety of white cells in nasal polyps and apoptosis is an important factor in the resolution of inflammation. However, the mechanism of glucocorticoids induced apoptosis in nasal polyp remains unclear. In this study the authors evaluated which pathways were engaged in apoptosis induced by DEX in an ex vivo model of nasal polyps. METHODS: Nasal polyp tissues were cultured using an air-liquid interface method. Cultures were maintained in the absence or presence of DEX (10 or 100 microM) for 24 hours. To investigate the involvement of the apoptotic signaling pathways in nasal polyp, such as caspase cascades, Fas-FasL signaling pathway, mitochondrial pathway and p38 mitogen-activated protein kinase (MAPK)/JNK pathway, the authors performed reverse transcription-polymerase chain reaction and Western blotting. RESULTS: The expression ratios of FasL, activated form of caspase-8, caspase-9, and caspase-3 were significantly higher in DEX-treated polyps (P<0.01). In the Bcl-2 family expression, the anti-apoptotic molecules, Bcl-2 and Bcl-XL decreased, but pro-apoptotic molecules, Bax increased, and Bid and Bad were activated. In the conventional MAPKs, JNK, and the phospho-p38 MAPK were significantly higher, but phospho-extracellular signal-regulated kinase (ERK)1/2 was significantly lower in DEX-treated polyps (P<0.01). CONCLUSION: DEX induces apoptosis of nasal polyp via caspase cascades, Fas-FasL signaling pathway, mitochondrial pathway and p38 MAPK/JNK pathway.

A Case of Angiomyolipoma of the Nasal Cavity / 대한이비인후과학회지

Angiomyolipoma (AML) is a generally benign tumor that usually occurs in the kidney. Nasal AML is extremely rare, with eight cases of AML in the nasal cavity have been reported in the English-language literature and only one case has been reported in Korea. Our case involved a 55-year-old male who presented with a history of frequent nasal bleeding on the right side of nasal cavity. Physical examination revealed a mass of about 1.2-cm in the right nasal cavity, which was removed by an endoscopic approach. Microscopically, it consisted of bundles of smooth muscle and blood vessels, mature fat cells in various proportions. We suggest that the cause of the nasal bleeding should be considered this case.

A Case of Ectopic Tooth in the Maxillary Sinus Associated with a Mucocele / 대한이비인후과학회지

Supernumerary, ectopic tooth eruption in a non-dental area is a rare entity. The ectopic development of tooth found in non-dental environment has been reported in places such as the nasal cavity, chin, maxillary sinus, mandibular bone, palate and orbital cavity. Ectopic tooth eruptions in the maxillary sinus are usually asymptomatic and are found incidentally during routine clinical or radiological investigations. The diagnosis is usually made by plain-film radiography. Computed tomography is indicated when an ectopic tooth is found prior to surgery. Standard treatment for an ectopic tooth is extraction of the tooth. Here, the authors present a case of supernumerary, ectopic tooth found in the maxillary sinus associated with a mucocele.

Distribution of Histologic Type of Nasal Polyp and Expression of Vascular Endothelial Growth Factor According to Nasal Polyp Type / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: To determine the frequency of the histologic types of nasal polyp in Korea and their relationships with respect to age, laterality, asthma, allergic rhinitis (AR) and expression of vascular endothelial growth factor (VEGF). SUBJECTS AND METHOD: Tissue slides obtained from 282 patients with nasal polyps were examined; polyps were classified either as eosinophilic polyp or chronic inflammatory polyp. VEGF expression was determined using immunohistochemical staining. RESULTS: Of the 282 subjects, 169 (59.9%) had chronic inflammatory polyps, 113 (40.1%) had eosinophilic polyps, and 232 (82.3%) had bilateral polyps. Twenty-two subjects (7.8%) had asthma and 23 (8.2%) had AR. There was no statistical relationship between nasal polyp type and laterality or the presence of asthma or AR. Of 10 children, 9 (90%) had chronic inflammatory polyps. VEGF expression was significantly higher in eosinophilic polyps than in chronic inflammatory polyps, and significantly higher in the samples of each polyp type from the subjects with AR than those without AR. In subjects with asthma, however, the VEGF expression did not differ between eosinophilic polyps and chronic inflammatory polyp samples. CONCLUSION: In the Korean population, chronic inflammatory nasal polyps are more common than eosinophilic nasal polyps. VEGF expression was the highest in eosinophilic polyps of the subjects with AR, suggesting that VEGF might contribute to the polyp formation via local allergic action.

Endoscopic Marsupialization of Postoperative Cheek Cyst with Orbital Floor Defect

BACKGROUND AND OBJECTIVES: The postoperative cheek cyst with orbital involvement is a rare condition and the treatment of eroded orbital floor is controversial. This study evaluated the efficacy of endoscopic marsupialization for treating postoperative cheek cyst with orbital floor defect and assessed the requirements of a direct orbital approach for orbital reconstruction. MATERIALS AND METHODS: The study involved a retrospective review of twelve patients with postoperative cheek cyst and orbital floor defect. Medical records were reviewed for details of previous surgery, presenting symptoms, surgical approach and the results of the operation. The maximum diameter of the involved orbital floor was calculated using the coronal imaging of paranasal sinus computed tomography (PNS CT). RESULTS: All patients had previously undergone Caldwell-Luc procedures. The most common symptom was pressure on the cheek. According to PNS CT, the maximum diameter of the involved orbital floor ranged from 0.7 to 3.1 cm (mean 1.46 cm) and the involved orbital area ranged from 0.35 to 4.23 cm2 (mean 1.87 cm2). All patients underwent only endoscopic marsupialization without orbital reconstruction. Postoperatively, all patients showed no recurrence of symptoms or required revision surgery. CONCLUSION: Endoscopic marsupialization without reconstruction of the orbital floor could be considered as a first treatment option for postoperative cheek cyst combined with orbital floor defect.

Acute Lymphadenitis with Cellulitis Caused by Staphylococcus lugdunensis / 대한진단검사의학회지

Although coagulase-negative staphylococci (CNS) have been considered part of the resident flora on the human skin, Staphylococcus lugdunensis is an unusually virulent CNS and can cause many types of infection. We report a rare case of acute lymphadenitis with cellulitis in the right infraauricular region caused by S. lugdunensis. A 62-yr-old woman visited the Department of Otolaryngology of Busan Paik university hospital. She had a palpable mass and swelling in the right infraauricular region and complained of aggressive pain and a febrile sensation in the region for 5 days. On the suspicion of abscess with infection, percutaneous aspiration was performed and smooth, flat, white, opaque colonies grew on a blood agar plate as a pure culture. The biochemical test results showed the organism to be catalase positive, tube coagulase negative, ornithine decarboxylase positive, slide coagulase positive, and latex agglutination tests for coagulase positive. The API Staph Kit was used to identify the isolate to the species level as S. lugdunensis with a 64.6% probability (profile 6716152). We confirmed the species identification of this strain by 16S rDNA sequence analysis. The patient's clinical condition improved with appropriate antimicrobial therapy and pus drainage.

Myxoma of the Maxillary Sinus : A Case Report / 대한이비인후과학회지

Myxomas of the maxillary sinus are uncommon benign tumors arising from primitive mesenchyme. They are usually manifested by slow, painless bony expansion with resultant facial deformity. The standard treatment for myxoma is radical excision. Although incomplete primary removal of tumor may result in high recurrence rates, complete radical resection may result in a significant functional and aesthetic defect. Therefore, a radical resection of the tumor with maximal preservation of surrounding anatomic structure is necessary. We describes a case of maxillary myxoma in a 31 year old male who underwent piece-meal surgery following debridement with microdebriders via intranasal endoscopic approach and Caldwell-Luc's approach for maximal preservation of anatomical structure.

5-Lipoxygenase Promotor Polymorphism in Nasal Polyp Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nasal polyps are the most common mass lesions in the nasal cavity and occur on both infectious and noninfectious basis, and genetic etiology is suspected in the development of nasal polyps. 5-Lipoxygenase is the first enzyme committed in the metabolic pathway leading to the intracellular synthesis of leukotrienes. Some studies have shown that leukotrienes were significantly higher in nasal polyps from aspirin-sensitive asthmatics than in nasal polyps from aspirin-tolerant asthmatics and normal nasal mucosa. The purpose of the present study is to evaluate whether genetic polymorphism of the core promoter region of the 5-lipoxygenase gene contributes to the development of nasal polyps. SUBJECTS AND METHOD: This study was conducted in 97 nasal polyp patients associated with chronic sinusitis and 92 healthy controls. Genetic polymorphisms of 5-lipoxygenase gene promoter were genotyped by PCR and direct sequencing. RESULTS: There were no significant differences between the 5-lipoxygenase gene promoter polymorphisms in nasal polyp patients with chronic sinusitis and those in healthy controls (p=0.76). In the nasal polyp patients associated with chronic sinusitis, the frequencies of 6-bp deletion were lower than those of healthy controls (OR, 0.88 95% CI, 0.48-1.60), but there was no statistical significance (p=0.67). The frequencies of 6-bp addition were higher than those of healthy controls (OR, 1.96; 95% CI, 0.33-10.6), but no significant difference was found (p=0.68). CONCLUSION: We concluded that 5-lipoxygenase gene promoter polymorphism did not show genetic predisposition with regard to nasal polyps in the Korean population.

A Case of Invasive Maxillary and Orbital Aspergillosis Inhematopoietic Stem Cell Transplantation Recipient with Severe Aplastic Anemia / 대한혈액학회지

Invasive aspergillosis (IA) of the paranasal sinuses is a rare infectious complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). However, immunocompromised patients are particularly at risk of fulminant IA. The high risk of an invasive fungal infection (IFI) following allogeneic HSCT is due to several factors, including neutropenia before engraftment, disruption of mucosal barriers by various preparative regimens and the use of broad-spectrum antimicrobial agents, as well as the immunosuppressive effects of prophylaxis and treatment of GVHD. As the therapy for an IFI following allogeneic HSCT is often unsuccessful, the mortality rate is increased by 95%. Therefore, early diagnosis is important to overcome the high mortality of this destructive disease. In previous studies, high risks for the early onset of IA were demonstrated in patients with severe aplastic anemia (SAA), independent of the day of engraftment. Here, we report a case of invasive aspergillosis of the maxillary sinuses and orbit in a 50 years old man with SAA, who underwent an allogeneic HSCT from a HLA-matched sibling conditioned with Cytoxan/Fludara/ATG.

The Effect of Selective Cyclooxygenase-2 Inhibitor on the Expression of Hypoxia-Inducible Factor-1alpha in Nasal Polyps / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used drugs in the world. NSAIDs are known to be potent inhibitors of the cyclooxygenase (COX) enzymes, a family of enzymes that catalyze the conversion of arachidonic acid to prostagladins. Expression of the gene encoding COX-2 might be regulated by hypoxia. Hypoxiainducible factors (HIFs) are activated by hypoxia. HIFs function in the hypoxic environment to orchestrate adaptational adjustments of vascular homeostasis through the activation of several dozens of target genes. The purpose of this study was to investigate whether a selective COX-2 inhibitor inhibits HIF-1alpha in human nasal polyps. SUBJECTS AND METHOD: Seven patients with nasal polyps with chronic sinusitis were selected. After the first biopsy, all patients were treated with selective cyclooxygenase inhibitor (Celebrax(R), 100mg, twice daily) for 7 days. At the end of the treatment period, a second set of biopsies was taken. HIF-1alpha messenger RNA (mRNA) production was measured by reverse transcriptase polymerase chain reaction and the protein expression of HIF-1alpha was determined by immunohistochemical staining. RESULTS: The expression of HIF-1alpha mRNA and protein were detected in nasal polyps. There was no significant difference in the mean level of HIF-1alpha mRNA between selective COX-2 inhibitoruntreated and treated nasal polyps (p>0.05). Immunohistochemistry shows diffuse and increased expression of HIF-1alpha in the nuclei of pseudostratified columnar epithelial cells. Endothelial cells and inflammatory cells including lymphocytes and histiocytes were expressed with HIF-1alpha in the stroma. Subcellular localization of HIF-1alpha were found mostly in the nucleus, but were occasionally observed in the cytoplasm of histiocytes. The expression of HIF-1alpha protein was not significantly different between selective COX-2 inhibitor-treated and selective COX-2 inhibitor-untreated nasal polyps (p>0.05). CONCLUSION: Selective COX-2 inhibitor did not inhibit HIF-1alpha expression in nasal polyps. Further studies are needed to find out the effect of selective COX-2 inhibitor on nasal polyps.

Association Between Nasal Polyp and -308, -238 Tumor Necrosis Factor-alpha Polymorphism / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nasal polyps are the most common mass lesion of the nasal cavity and it occurs on both infectious and noninfectious basis, and especially because genetic etiology is suspected in the development of nasal polyp. Tumor necrosis factor-alpha (TNF-alpha) is a pivotal cytokine in inflammatory and infectious diseases, and increased tissue TNF-alpha levels have been observed in the inflammatory type of nasal polyp. It has been known that several TNF-alpha gene polymorphisms in a promoter region are related to TNF-alpha production. Among them, the G to A substitution at the position 308 (TNF-alpha 308A) and at the position 238 (TNF-alpha 238A) in the TNF-alpha promoter are associated with the high or low production of TNF-alpha. Therefore, we investigated the association between with TNF-alpha promoter polymorphism and nasal polyps. SUBJECTS AND METHODS: This study included 104 patients with polyp associated chronic sinusitis and 104 healthy controls. TNF-alpha promoter genotype was screened by PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: In the nasal polyp associated chronic sinusitis, the frequency of TNF-alpha 308A was higher than those of healthy controls (OR, 1.739;95% CI, 0.653-4.633). But there was no statistical significance between distribution of TNF-alpha gene polymorphism and nasal polyps. Frequency of TNF-alpha 238A was higher in nasal polyp than in healthy controls, but no significant differences were found. We concluded that TNF-alpha polymorphism did not show genetic predisposition with regard to nasal polyp in Korean patients.

The Clinical and Pathological Study of the Adenoid Vegetation Above the Age of 20 / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The adenoid increases progressively in size during early childhood, reaching a maximum at the age between 3 and 7. It begins to atrophy and involute after puberty and almost disappears before the age of 20. However, a few authors stated that persistence of the adenoid in adult life is not uncommon and the nasopharyngeal lymphoid tissue can undergo prominent or even marked hyperplasia in adults. We investigated clinical and pathological features of the patients who underwent adenoidectomy at ages beyond 20. SUBJECTS AND METHOD: A retrospective study was performed on 18 patients who underwent adenoidectomy due to adenoid vegetation from October 1997 to December 2002 at Pusan Paik Hospital and they compared the results with children of ages 3 to 10 years. To evaluate hypertrophy, adenoidal-nasopharyngeal ratios (A/N ratio) obtained using simple linear measurements from lateral skull radiographs were described. To investigate pathologic features, all excised adenoids were fixed in neutral 10 % formalin and serial sections of 5 microM thick were prepared and stained by Haematoxylin and Eosin. RESULTS: The A/N ratios of the studied patients were from 7.5 to 9.0. The main symptom of the patients was snoring. Others were nasal obstruction, postnasal drip and frequent upper respiratory infection. The prominent pathologic findings in the patients were increased squamous metaplasia of the surface epithelium and parenchymal fibrosis. CONCLUSION: Snoring and nasal obstruction were often caused by adenoid enlargements in adults. Because the examination of the nasopharynx was inadequate, many cases of enlarged adenoid in adults were misdiagnosed. Pathologic features of enlarged adenoid in adults were slightly different from those in children.

Expression of Angiogenic Growth Factor in Middle Ear Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Angiogenesis is important both in normal and pathologic processes, including wound healing and inflammation. Because proliferating tissues require an enhanced blood supply, angiogenesis appears to be a prerequisite for expansion of cholesteatoma. This study was aimed to investigate mRNA and protein expression of angiogenic growth factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha) and platelet derived-endothelial cell growth factor (PD-ECGF) in middle ear cholesteatoma. SUBJECTS AND METHOD: Cholesteatoma tissues and retroauricular skins were obtained from 12 patients during operation. The mRNA expression was detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the degree of expression was measured by comparing density ratio of beta-actin by NIH imaging analysis system. The protein expression was evaluated by immunohistochemistry, and the degrees of expression in epithelial, endothelial, inflammatory cells of cholesteatoma and retroauricular skin were judged by two pathologists and then converted on a 5-grade rating scale according to intensity of expression. RESULTS: The expression rate of mRNA in cholesteatoma and retroauricular skin was 67.7 and 33.3% in VEGF, 75.0 and 50.0% in bFGF, 53.8 and 8.3% in TGF-alpha, 67.7 and 75% in PD-ECGF. There was statistically significant difference only in TGF-alpha (p0.05). The degrees of VEGF, bFGF and PD-ECGF protein expression in cholesteatoma tissue were more intense at the inflammatory (p0.05) than in retroauricular skin. And the degree of TGF-alpha protein expression in cholesteatoma tissue was more intense at all three cells (p<0.05) than in the retroauricular skin. CONCLUSION: These results suggest that angiogenesis processes in cholesteatoma perimatrix and the expression of angiogenic growth factors are upregulated by mRNA. Further studies for evaluating the factors that can affect the expression of mRNA and also for disclosing the roles and control mechanisms of these factors in cholesteatoma angiogenesis must be followed.

Expression of Hypoxia-Inducible Factor-1alpha and Correlation between Hypoxia-Inducible Factor-1alpha and Vascular Endothelial Growth Factor in Nasal Polyps / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The function of hypoxia-inducible factors (HIFs) in the hypoxic environment is to orchestrate adaptational adjustments of vascular homeostasis through the activation of several dozens of target genes including vascular en-dothelial growth factors (VEGF). It has been suggested that VEGF is involved in the pathogenesis of nasal polyp. The purpose of this study is to determine and correlate concentrations of HIF-1alpha and VEGF in nasal polyps. MATERIALS AND METHOD: Twenty-five nasal polyps were collected at the time of endoscopic sinus surgery. The production of HIF-1alpha and VEGF messenger RNA (mRNA) was measured by reverse transcriptase polymerase chain reaction (RT-PCR) and HIF-1alpha and VEGF proteins were determined by immunohistochemical staining. RESULTS: The expressions of HIF-1, VEGF mRNA and proteins were detected in nasal polyps. RT-PCR demonstrated that the level of mRNA expression of HIF-1alpha and VEGF were 1.12+/-0.33 and 1.11+/-0.42, respectively. A positive correlation was observed between HIF-1alpha and VEGF mRNA (correlation coefficient [r]=0.49, p<0.05). The immunohistochemical studies revealed that HIF-1alpha was predominantly expressed in surface epithelial cells, submucosal glandular cells, endothelial cells and inflammatory cells in the stroma and VEGF was more strongly and diffusely expressed in subglandular epithelial cells, vascular endothelial cells, and inflammatory cells than in surface epithelial cells. The expressions of HIF-1alpha and VEGF proteins were 3.24+/-1.80 and 3.52+/-1.89, respectively. A positive correlation was observed between HIF-1alpha and VEGF proteins (r=0.76, p<0.05). CONCLUSION: We suggest that HIF-1alpha has a role in inducing VEGF in nasal polyps, and hypoxia is an important factor in the growth of nasal polyps.