Frequency of Epstein-Barr virus and human papilloma virus in patients with nasopharyngeal carcinoma.

PURPOSE: Nasopharyngeal cancer is a type of malignancy originating from the epithelial cells lining the nasopharynx. In genetic and environmental factors, infection with Epstein-Barr virus is one of the particular factors held accountable for the etiopathogenesis. Human papillomavirus has been associated with cervical, anogenital, and oropharyngeal cancers. The aim of the present study is to demonstrate the presence and incidence of Epstein-Barr virus and human papillomavirus in patients with nasopharyngeal cancer. METHODS: The information collected for these patients included age at the time of biopsy, gender, alcohol consumption and smoking, and histopathological type of nasopharyngeal cancer. Only patients for whom nasopharyngeal biopsy was performed as punch biopsy were included in the study. In situ hybridization was performed with formalin-fixed, paraffin-embedded tissue sections for Human Papillomavirus and Epstein-Barr virus nucleic acids obtained by means of automated Ventana BenchMark Medical system RESULTS: Utilizing in situ hybridization with samples obtained from 56 patients diagnosed with nasopharyngeal cancer. Epstein-Barr virus was positive in 41 out of the 56 (73.2%) patients, while human papillomavirus was positive in 3 (5.4%), and 1 patient (1.8%) had co-infection. Thirty seven (90.2%) of the 41 patients positive for Epstein-Barr virus were Type-2 according to WHO, while 4 (9.8%) were Type-1. All three patients (100%) with Human Papillomavirus positivity were Type-2 according to WHO. CONCLUSIONS: This study shows the close association between nasopharyngeal cancer and Epstein-Barr virus whereas such an association is not shown for Human Papillomavirus.

Does noise exposure during pregnancy affect neonatal hearing screening results?

OBJECTIVE: The aim is to investigate whether noise is effective on hearing screening tests of neonates born to mothers exposed to noise during pregnancy. MATERIAL AND METHOD: Screening results of 2653 infants from the period of January 2013-May 2017 were evaluated. Transient Evoked Otoacoustic Emissions (TEOAE) and Auditory Brainstem Response (ABR) were used. Infants of 65 mothers exposed to noise (LAeq 80-85 dBA/8 hours/day) during pregnancy (Week ± SD; 32.58 ± 2.71) comprised the study group while the control group consisted of infants of 2588 mothers without noise exposure. RESULTS: Among the 65 infants, 23 (35.4%) passed screening at the first emission test (OAE1); 34 (52.3%) at the second emission test (OAE2); 7 (10.8%) at the ABR stage, 1 (1.5%) infant was referred to a tertiary center. In the control group, 458 (17.7%) infants passed at OAE1; 1822 (70.4%) at OAE2; 289 (11.2%) at ABR stages, 19 (0.7%) infants were referred to a tertiary center. The rate of infants that passed screening at OAE1 in the study group was high (P = 0.00001). Sixty-four (98.46%) infants in the study group and 2569 (99.26%) infants in the control group passed the tests. The difference between the two groups was not significant, indicating that exposure to noise during pregnancy had no unfavorable effects on auditory functions (P = 0.392). CONCLUSION: Unfavorable effect of noise exposure during pregnancy was not observed on auditory functions of the infants. The higher rate of infants that passed the screening test at OAE1 stage in the study group raised the question, "Does the exposure of the noise at exposure action levels (80-85 dB A) during pregnancy contribute to auditory maturation of fetus?"

Possible Ototoxic Effects of Topical Rifamycin Application: An Electrophysiological and Ultrastructural Study.

OBJECTIVE: This study aimed to investigate possible ototoxicity associated with topical rifamycin application via electrophysiological tests and ultrastructural examinations. METHODS: Electrophysiological assessment was performed with tympanometry, auditory brainstem response (ABR), and distortion product otoacoustic emission (DPOAE) measurements. This study was conducted on 40 ears of 20 guinea pigs that were detected to have normal hearing thresholds. The animals were randomly assigned to three groups: Group 1 (n=12) received 0.1 mL rifamycin, Group 2 (n=8) received 0.1 ml gentamycin, and Group 3 (n=20) received 0.1 mL physiological saline. The antibiotics and saline solutions were administered via intratympanic injections. After five injections every other day, electrophysiological tests were performed again on the 15th day. After electrophysiological measurements, the temporal bones of all guinea pigs were prepared for ultrastructural examinations and the cochlear surface morphology was examined by scanning electron microscopy (SEM). RESULTS: The animals in group 3 did not show a statistically significant change in their DPOAE signal/noise ratio (SNR) or ABR thresholds (p>0.05). In groups 1 and 2, the reduction in the DPOAE SNR and the increase in the ABR threshold were statistically significant (p<0.05). Regarding SEM examination results, the animals in groups 1 and 2 showed statistically significant outer hair cell damage and cochlear degeneration due to the ototoxic effect of the drugs (p<0.05), whereas the animals in group 3 showed no significant damage (p>0.05). CONCLUSION: The results indicate that rifamycin application to the middle ears of guinea pigs has mild ototoxic effects on their inner ears.

[The evaluation of the outcomes of nasal obstruction surgery by acoustic rhinometry measurements and effects of nasal obstruction on daytime sleepiness]. / Nazal obstrüksiyon cerrahi sonuçlarinin akustik rinometri ölçümleri ile degerlendirilmesi ve burun tikanikliginin gündüz uykululuk hali üzerine etkisi.

OBJECTIVES: In this study, we aimed to investigate the correlation between nasal obstruction findings of the patients who underwent nasal surgery, as assessed by analog scales for the patients and physician and acoustic rhinometry measurements and to establish the effect of nasal obstruction on daytime sleepiness. PATIENTS AND METHODS: Between August 2007 and September 2008, 55 patients (40 males, 15 females; mean age 30 years; range 15 to 56 years) who admitted with the complaint of nasal obstruction and underwent nasal surgery were included. Pre- and postoperative acoustic rhinometry measurements for both nasal cavities were performed. Nasal obstruction was graded by the analog scales for patients and physicians. Epworth Sleepiness Scale (ESS) was used for the evaluation of nasal obstruction on daytime sleepiness. RESULTS: In the preoperative period, a statistically significant correlation between the analog scales for the patients and physicians, and acoustic rhinometry values was found, while no statistically significant correlation was available in the postoperative period. A statistically significant correlation was also observed between pre- and postoperative analog scales for the patients and physicians. There was a statistically significant difference between the pre- and postoperative ESS scores. CONCLUSION: Acoustic rhinometry is a reliable method which provides objective data regarding the effects and outcomes of surgery. The analog scales are also useful to establish the degree of nasal obstruction. Nasal obstruction has an effect on increased complaints of daytime sleepiness.

[Effect of the levels of vascular endothelial growth factor-A and C on the prognosis of patients with laryngeal carcinoma]. / Larenks kanserli hastalarda vasküler endotelyal büyüme faktörü A ve C düzeylerinin prognoza etkisi.

OBJECTIVES: In this study, we determined the prognostic importance of vascular endothelial growth factor (VEGF)-A and C values and their relationship with tumor stages and neck lymp node involvement and also, the relationship between microvessel density and tumor stage in the pathologic specimens. PATIENTS AND METHODS: Thirty-three male patients (mean age 57.8±7.2 years; range 49 to 69 years) who underwent surgical treatment for laryngeal squamous cell carcinoma and a control group of 13 healthy male subjects (mean age 54.2±6.1 years; range 41 to 62 years) were included in the study. Patients were divided into two groups: the early-stage group consisting of patients with T1 and T2 stage tumors and the advanced stage group including patients with T3 and T4 stage tumors. Patients are evaluated in terms of plasma VEGF-A and C levels before and six months after the surgery. In the pathologic specimens, CD 31 was used for immunohistochemical staining. For each patient the number of microvessels per millimeter square (microvessel density) was determined. RESULTS: The preoperative plasma VEBF-A levels of the patients with early-stage tumors were significantly lower compared to those of the control group, while there was no significant difference between the preoperative levels of the patients with advanced stage tumors and the levels of the control group. There was no significant difference between the preoperative and postoperative 6th month VEGF-A levels of the patients both in the early-stage and the advanced stage groups. The preoperative plasma VEGF-C values of the patients with lymph node involvement were significantly lower than those of the patients with early-stage tumors. There was no significant difference between the VEGF-C levels in pre- and postoperatively at six months after the operation of patients with lymph node involvement. There was no significant difference between the preoperative VEGF-C levels of the patients with lymph node involvement and those without lymph node involvement. No significant difference was found in microvessel density between the cases with early and advanced stage tumors. CONCLUSION: It was seen that the plasma VEGF-A value did not increase in patients with laryngeal cancer and rather it is low in patients with early-stage disease. No relationship was found between the plasma VEGF-C values and cervical lymph node involvement.

Laryngeal chondroma: a rare diagnosis in this localization.

Primary chondroid tumors of the larynx represent less than 1% of all laryngeal tumors. Most of them are chondromas and they often involve to the cricoid cartilage. A 31-year-old male patient applied to the oto-laryngology service with a history of dysphonia and dyspnea. Microlaryngoscopy revealed 2 cm sized, ill-defined, covered with regular mucosa, porous, and hard mass on posterior surface of crycoid cartilage in subglottic area. Following the excision of the lesion, histopathologic examination revealed as chondroma. Two years later, local recurrence was detected and the diagnosis was again chondroma. There was no complaint of the patient in last 3 and half years of follow-up. Chondroma should carefully be differentiated from chondrosarcoma and the patients should be followed for possible recurrences.

Dermoid cyst of the parotid gland: first pediatric case.

A dermoid cyst is the result of inclusion of epithelial cells along the lines of embryonic closure. Dermoid cysts of the head neck are uncommon and account for only 7% of all such cysts. They are most often reported as arising in the floor of the mouth. Dermoid cyst is rarely seen in the parotid gland. To our knowledge, there have been only six previous case reports in the English literature. Dermoid cyst of the parotid gland in pediatric patient has not been previously reported in the literature. This is the first case report concerning a dermoid cyst in a pediatric patient.

Primary nasopharyngeal tuberculosis.

Primary nasopharyneal tuberculosis is a rare disease which is commonly present with cervical lymphadenopathy. It is hard to differenciate the diagnosis of tuberculosis from nasopharyngeal carcinoma. Histologic and bacteriologic evaluation is required for diagnosis. A male patient at the age of nineteen applied to our clinic with the complaints of a mass in the neck, congestion in the nose, night sweating and weight loss. Clinical presentation of the patient was similar to that of a malignant tumor of the nasopharynx. Histologic and bacteriologic study supported the diagnosis of tuberculosis. After anti-tuberculosis therapy, the complaints of the patient regressed. We present a nasopharyngeal tuberculosis case in this study.

Synchronous tonsil, gallbladder, and cardiac metastases without any other visceral metastases of malignant melanoma.

BACKGROUND: Malignant melanoma is a highly unpredictable tumor that has capacity to metastasize to any organ. A better understanding is needed of the clinicopathologic features of metastatic melanoma and, in particular, of its rare manifestations. CASE REPORT: A 33-year-old woman with a past medical history of malignant melanoma presented with symptoms of throat discomfort and bleeding. On physical examination, a dark pigmented lesion was observed on the right tonsil. Tonsillectomy was performed, and melanoma was diagnosed. Computed tomography of the thorax and abdomen revealed a filling defect in the right atrium and a 4-cm gallbladder mass. Echocardiography revealed a right atrial mass. No further metastasis was detected by whole body (18)F-fluorodeoxyglucose positron emission tomography. Each metastasis was completely resected with clear margins. The pathologic diagnosis of the resected masses was malignant melanoma. 3 weeks after the final surgery, temozolomide was started. The patient has been followed up for 9 months after diagnosis of the first recurrence, and no new metastases have been detected. CONCLUSION: We report a case with synchronous tonsil, gallbladder, and heart metastases without any other common sites of metastasis of melanoma. The patient was successfully treated with aggressive surgery followed by temozolomide.

[Papillary carcinoma arising from a thyroglossal duct cyst]. / Tiroglossal duktus kistinden kaynaklanan papiller karsinom.

Thyroglossal duct cyst is the most common midline congenital neck anomaly. Carcinoma arising from a thyroglossal duct cyst is a rare entity, the most common histological type being papillary carcinoma. A 23-year-old male patient presented with a painless mass at the level of the hyoid bone in the midline of the neck. It was mobile on swallowing. With an initial diagnosis of thyroglossal duct cyst, the lesion was removed with the Sistrunk procedure. Histopathological examination of the surgical specimen showed papillary carcinoma arising from the thyroglossal duct cyst. Thyroid suppression therapy was initiated postoperatively. The patient has been under follow-up for 30 months with no recurrence.

Evaluation of hearing in children with autism by using TEOAE and ABR.

Assessment of auditory abilities is important in the diagnosis and treatment of children with autism. The aim was to evaluate hearing objectively by using transient evoked otoacoustic emission (TEOAE) and auditory brainstem response (ABR). Tests were performed on 30 children with autism and 15 typically developing children, following otomicroscopy and tympanometry. The children with autism were sedated before the tests. Positive emissions and normal hearing level at ABR were obtained in both ears of all children in the control group and of 25 children with autism. TEOAE and ABR results varied in the remaining five children with autism. The mean III-V interpeak latencies (IPLs) in both ears of children with autism were longer than those in the control group. Hearing loss may be more common in children with autism than in typically developing children.

[Analysis of the psychological symptoms of patients following surgery for laryngeal cancer]. / Larenks kanseri nedeniyle ameliyat olan hastalarin psikolojik semptom dagiliminin incelenmesi.

OBJECTIVES: We evaluated psychological symptoms of patients who underwent partial or total laryngectomy for larynx cancer. PATIENTS AND METHODS: The study included 63 patients who underwent total (n=41) or partial (n=22) laryngectomy. The control group consisted of 20 healthy individuals with similar gender, age, and sociocultural characteristics. During the postoperative follow-up, the psychological symptom distribution of the patients was assessed with the Symptom Check-List-90-Revised (SCL-90-R). RESULTS: The SCL-90-R inventory was administered at a mean of 20.6 months (range 10 to 86 months) postoperatively. Patients with total laryngectomy had significantly higher scores than the controls in the subscales of interpersonal sensitivity, depression, anger-hostility, phobic anxiety, and global symptom index (p<0.05). Partial laryngectomy patients exhibited lower scores than total laryngectomy patients, and higher scores than the control group. The only significant difference between partial laryngectomy patients and the control group was in the subscale of anger-hostility (p<0.05). CONCLUSION: Patients with laryngeal cancer should be given postoperative psychological support to minimize adverse effects of total or partial laryngectomy.

[Assessment of patients with sudden hearing loss by transcranial Doppler ultrasonography]. / Ani isitme kayipli hastalarin transkraniyal Doppler ultrasonografi ile degerlendirilmesi.

OBJECTIVES: We evaluated the utility of transcranial Doppler ultrasonography in determining the vascular pathology in patients with sudden hearing loss. PATIENTS AND METHODS: The study included 13 patients (11 males, 2 females; mean age 46.6+/-17.7 years; range 18 to 66 years) with a diagnosis of sudden hearing loss. Patients having chronic otitis media or other middle ear diseases or a history of surgery in the affected ear were excluded. All the patients were evaluated by pure-tone audiometry, impedance audiometry, transient evoked otoacoustic emissions, auditory brainstem responses, and transcranial Doppler ultrasonography. The results were compared with those of a control group of 19 age- and sex-matched healthy subjects (12 males, 7 females; mean age 46.8+/-6.9 years; range 33 to 58 years) who did not have any ear disease or a history of ototoxic drug intake or working in a noisy environment, and no pathology on otoscopic and audiometric examinations. RESULTS: Compared to the normal ear, the mean blood flow and systolic flow velocities of the vertebral artery were significantly decreased, and the mean pulsatile index was significantly increased on the affected side. The mean flow velocity of the basilar artery in the patient group was lower than that found in the control group. CONCLUSION: Transcranial Doppler ultrasonography can be used for the evaluation of vascular involvement of the vertebral and basilar arteries in patients with sudden sensorineural hearing loss.

[The protective effect of oral magnesium supplement on noise-induced hearing loss]. / Gürültüye bagli isitme kaybinda magnezyumun koruyucu etkisi.

OBJECTIVES: We investigated the beneficial effect of magnesium in the prevention of noise-induced cochlear damage in guinea pigs by transient evoked otoacoustic emissions (TEOAE). STUDY DESIGN: Thirty-nine guinea pigs with normal auropalpebral reflex were randomly divided into control (n=20) and study (n=19) groups. All the animals were subjected to wide-band noise standardized at a mean of 98+/-2 dB for 16 hours a day for 10 days in a sound isolated cabin. The study animals received 39 mmol/l MgCl2 throughout the study period starting from 15 days before noise exposure. Otomicroscopic examination, auditory brain stem response (ABR) and TEOAE measurements were performed before and after noise exposure. Tympanometric measurements were performed to eliminate possible middle ear pathologies. RESULTS: Although the mean TEOAE response and reproducibility values showed significant decreases after noise application in the control group (p<0.001), they were not affected significantly in magnesium-treated animals. Post-exposure mean TEOAE response and reproducibility values significantly differed between the two groups (p<0.001). Noise-induced elevations in ABR thresholds were significant in both groups (p<0.001); however, it was noted that hearing levels were better preserved in the study group. CONCLUSION: Our data suggest that oral magnesium intake may be beneficial in the prevention of cochlear damage in noise-induced hearing loss.

Influence of anaesthetic agents on transient evoked otoacoustic emissions and stapedius reflex thresholds.

This aim of this study was to determine the effect of anaesthetic agents on stapedius reflex (SR) thresholds and transient evoked otoacoustic emissions (TEOAE). Fifty patients who were scheduled for operation and who had normal hearing were included in the study. All were given midazolam for premedication and propofol for induction. Anaesthesia was maintained in five different ways in each group of 10 patients. Groups I-IV received inhalational anaesthesia: group I received 70 per cent N2O plus 30 per cent O2, group II sevoflurane, group III desflurane and group IV halothane. Group V received total intravenous anaesthesia with propofol plus sufentanil. The SR and TEOAE of the patients were measured four times: on the day before surgery (first measurement), after premedication (second measurement), after induction of anaesthesia (third measurement) and during maintenance of anaesthesia (fourth measurement). Midazolam significantly increased ipsilateral and contralateral SR thresholds and decreased TEOAE wave reproducibility. Propofol significantly increased only the SR thresholds. The other anaesthetic agents significantly increased only the contralateral reflex thresholds. Of these, the highest increase was seen after sevoflurane and the lowest after halothane. The changes in TEOAE wave reproducibility due to anaesthetic agents used for maintenance were not significant. We concluded that midazolam premedication may affect audiological evaluation with SR and TEOAE tests, and sevoflurane should not be used when it is necessary to measure SR under general anaesthesia.

Otoacoustic emissions in young adults with a history of otitis media.

The aim of this study was to investigate otoacoustic emissions in young adults who had a history of otitis media (OM) in childhood and to assess whether a history of OM had an irreversible effect on hearing. We studied 116 cases between 15 and 25 years of age, divided into three groups. Each subject underwent a single examination comprising otoscopy, pure-tone audiometry (PTA), tympanometry, and transient evoked otoacoustic emission (TEOAE) and distortion product otoacoustic emission (DPOAE) testing. Subjects in the first and second groups had normal audiometric hearing thresholds and type A tympanograms. The only difference between the first and second group was the presence or absence of a history of OM. The third group consisted of patients diagnosed as having active OM; these patients had poorer hearing thresholds and type B or C tympanograms. After statistical analysis of TEOAE and DPOAE results (one-way analysis of variance test), significant differences were noted between groups. Otoacoustic emission levels were, unsurprisingly, lowest in the third group, as expected. However, the most striking result in the study was that significantly fewer otoacoustic emissions were detected in subjects with a history of OM than in subjects without a history of OM. These findings suggest that OM in childhood may cause minor but irreversible damage to the middle ear or cochlea. Otoacoustic emissions testing can be used to detect this sub-clinical damage.

[The predictive value of assessing mastoid pneumatization in pre-dive examinations]. / Dalici muayenesinde mastoid pnömatizasyon derecesinin barotravmayi öngörmedeki degeri.

OBJECTIVES: We investigated the value of assessing the degree of mastoid pneumatization in predicting middle ear barotrauma -the most common problem in sport SCUBA divers- in comparison with that of the conventional pre-dive examination method, the Valsalva maneuver. MATERIALS AND METHODS: Thirty-four volunteer sport SCUBA divers having normal pre-dive examination findings were included. The Valsalva test was performed in all the divers. Mastoid pneumatization for each ear was calculated on a Schuller's view radiography. Pneumatization of = or <30 cm2 was accepted as poor (prone to barotrauma) and >30 cm2 was accepted as good (not prone to barotrauma). During the observation period, the divers were monitored with regard to barotrauma symptoms and signs. RESULTS: The degree of mastoid pneumatization was = or <30 cm2 in 26 ears (38%) of 16 divers (47%). The Valsalva test was negative in eight ears (12%) of six divers (18%). During a total of 1001 dives, symptomatic middle ear barotrauma occurred in 28 dives (2.8%), i.e. in 21 ears (31%) of 16 divers (47%). Of these, the degree of mastoid pneumatization predicted barotrauma in 11 (69%) divers, whereas the Valsalva test was negative in only three (19%) (p<0.05), with sensitivity, specificity, positive and negative predictive values, and efficiency being 69% and 19%, 72% and 83%, 69% and 50%, 72% and 54%, and 71% and 53%, respectively. CONCLUSION: The value of assessing mastoid pneumatization in predicting middle ear barotrauma in sport SCUBA divers is higher than that of the Valsalva test.

Combined Heermann and Tos (CHAT) technique in cholesteatoma surgery: surgical technique and preliminary results.

The combined Heermann and Tos (CHAT) technique is the combination of Heermann's 'cartilage palisade tympanoplasty' and Tos's 'modified combined approach tympanoplasty = modified intact canal wall mastoidectomy'. The first author (Cem Uzun) performed the CHAT technique as a one-stage operation in 15 ears of 15 patients with cholesteatoma. Two patients (one with a follow up of less than six months and one who did not show up at the final re-evaluation) were excluded from the study. Median age in the remaining 13 patients was 37 years (range: 14-57 years). Cholesteatoma type was attic, sinus (Tos tensa type 1) and tensa retraction (Tos tensa type 2) in six, five and two ears, respectively. Cholesteatoma stage was Saleh and Mills stage 1, 2, 3, 4 and 5 in one, three, four, four and one ear, respectively. The eustachian tube was not involved with cholesteatoma in any ear. After drilling of the superoposterior bony annulus, transcanal atticotomy with preservation of thin bridge and cortical mastoidectomy with intact canal wall, the cholesteatoma was removed, and the eardrum and atticotomy were reconstructed with palisades of auricular cartilage. Type I tympanoplasty was performed in two ears, type II in nine ears and type III (stapes absent) in two ears, with either autologous incus (eight cases), cortical bone (two) or auricular cartilage (one). No complication occurred before, during or after surgery. Oto-microscopy and audiometry were done before and at a median of 13 months after surgery (mean 14 months, range 7-30 months). There was no sign of residual or recurrent cholesteatoma in any patient during the follow-up period. At the final examination, all ears were dry and had an intact eardrum except one with a small, central hole, which had been seen since the early post-operative period. Clean and stable attic retraction with a wide access was observed in two ears. Post-operative hearing at the final evaluation was better (change > 10 dB) than the pre-operative one in nine ears and did not change in the remaining four. Pre- and post-operative mean hearing values were, pure-tone average 47 and 35 dB (p = 0.01) and air-bone gap 30 and 20 dB (p = 0.02), respectively. With the CHAT technique, cholesteatoma can be completely and safely removed from the middle ear, and a durable and resistant reconstruction of the middle ear with reasonable hearing can be achieved. However, a further study should analyse long-term results of a larger patient group.

Thyroid gland tuberculosis with endolaryngeal extension: a case with laryngotracheal dyspnoea.

Tuberculosis affecting the thyroid gland is a rare condition. We present the case of a 30-year-old man with thyroid tuberculosis whose presenting complaints were dyspnoea and hoarseness. There was a cystic mass in the posterosuperior right thyroid lobe extending into the paraglottic space. There was also recurrent laryngeal nerve involvement. We performed surgery and administered post-operative antituberculous treatment.

Use of mometasone furoate aqueous nasal spray in the treatment of rhinitis medicamentosa: an experimental study.

OBJECTIVE: We aimed to investigate, histopathologic changes in the nasal mucosa of guinea pig's after prolonged administration of oxymetazoline and the development of rhinitis medicamentosa, and the efficacy of mometasone furoate aqueous nasal spray and saline in reversing the ultrastructural changes attributable to rhinitis medicamentosa. METHODS: In the study, 24 male guinea pigs (500 to 600 gr) were used. Oxymetazolin (0.05%) was sprayed into the nasal cavities of the guinea pigs 3 times daily for 8 weeks. At the end of this period, 6 guinea pigs were killed and examined to make sure that the animals had developed rhinitis medicamentosa. The remaining guinea pigs were randomly divided into 3 groups. In the first group, one spray-puff of 0.05% mometasone furoate aqueous nasal spray (50 microg) was applied twice daily for 14 days. In the second group, saline solution (0.9% NaCl) was applied twice daily for 14 days. No treatment was performed in the third group. At the end of the treatment period, nasal mucosal changes were evaluated by light microscopy and electron microscopy. RESULTS: After oxymetazolin application for 8 weeks, the main histologic changes were edema, congestion, proliferation of subepithelial glands, and squamous cell metaplasia. After topical mometasone furoate aqueous spray application for 2 weeks, the edema fluid was found to diminish markedly. In the saline and no treatment groups, edema and congestion continued. In these groups of guinea pigs, fibrosis has been seen in the nasal mucosa. CONCLUSION: We found that mometasone furoate nasal spray was effective against experimentally induced rhinitis medicamentosa in guinea pigs. Mometasone furoate nasal spray may have value in the treatment of patients with rhinitis medicamentosa.