Specific immune response of the adenoids to a respiratory antigen

The specific antibody response of the adenoids to a respiratory antigen was investigated, both in vitro and in vivo. The in vitro immunoglobulin (Ig) production of adenoidal and tonsillar lymphocytes in the same patient in 18 cases was measured by an enzyme-linked immunosorbent assay. Adenoidal lymphocytes produced more IgM than IgG or IgA under culture conditions without any mitogens, whereas IgG was the major Ig produced by tonsillar lymphocytes. The same results were obtained when cultured with pokeweed mitogen. Under culture conditions with Dermatophagoides farinae (mite) antigen, adenoidal lymphocytes produced only specific IgM class antibody, and at a level significantly greater than tonsillar lymphocytes. Through an in vivo study, we established experimental adenoidal tissue in the guinea pig by long-term exposure to an ovalbumin aerosol. Infiltration of cells producing the specific antibody against an ovalbumin was demonstrated in the epipharyngeal mucosa using immunofluorescent staining. Our results confirm that the adenoids play a role in specific immune responses to respiratory antigens.     

扁桃体和腺样体肥大患儿心理行为特征的对照研究

目的：扁桃体和腺样体肥大对儿童心理行为的影响。方法：采用湖南医科大学龚耀先1986年修订的Achenbach儿童行为量表对97例扁桃体和腺样体肥大患儿进行心理行为的检测。结果：扁桃体和腺样体肥大儿童心理行为异常检出率明显高于对照组。扁桃体和腺样体肥大患儿心理行为的总粗分均显著高于对照组,差异有统计学意义（P〈0．01）。男孩主要表现在分裂性、交往不良、强迫性、多动、违纪方面,女孩主要表现在体诉、多动、攻击方面,均差异有统计学意义（均P％0．01）。行扁桃体切除术和腺样体切除术3个月后,对患儿进行第2次测试,术后男孩在分裂性、抑郁、强迫性、体诉方面分数及总粗分明显低于术前值,差异有统计学意义（P〈0．05）。女孩在抑郁,强迫分裂性、违纪、攻击、残忍方面分数及总粗分明显低于术前值,差异有统计学意义（P〈0．05）。心理行为异常检出率与患儿年龄呈正相关。结论：扁桃体和腺样体肥大对患儿的心理行为有比较明显的影响,应加强对扁桃体和腺样体肥大患儿的心理行为干预。     

Actinomycosis in obstructive tonsillar hypertrophy and recurrent tonsillitis

A quantitative analysis of adenoid and tonsillar specimens from 460 patients was performed. The patients underwent tonsillectomy or adenotonsillectomy for either recurrent tonsillitis or obstructive tonsillar hypertrophy. Histologic preparations revealed Actinomycetes as statistically more prevalent in the obstructive population. The presence of Actinomycetes in the adenotonsillar core of this diagnostic group may indicate an etiologic role for this organism in tonsillar and adenoidal hypertrophy.     

The potential inflammatory role of arginase and iNOS in children with chronic adenotonsillar hypertrophy

OBJECTIVE: Nitric oxide (NO) induced tissue damage has been implicated in the pathogenesis of several diseases. Although recurrent/chronic tonsillitis and hypertrophy are still the most frequent surgical procedures carried out on children in order to cure these pathologies, etiopathogenetic mechanisms underlying these entities are still unknown. We aimed to investigate the potential inflammatory role of NO regulatory enzymes, arginase and inducible nitric oxide synthase (iNOS), in children with adenotonsillar hypertrophy. MATERIALS AND METHODS: The study consisted of 22 children with chronic adenotonsillar hypertrophy and 30 control subjects with similar age and sex. All the patients and/or their parents had complaints of snoring, mouth breathing and pausing of breathe during sleep at least 6 months. All patients underwent an adenotonsillectomy operation under general anesthesia with curettage and cold dissection methods. Venous blood samples were taken pre-operatively and 4 weeks post-operatively. iNOS activity was based on the diazotization of sulfanilic acid by nitric oxide at acid pH and subsequent coupling to N-(1-naphthtyl)-ethylenediamine. Arginase activity was measured by the spectrophotometric method. RESULTS: The mean pre-operative and post-operative arginase activities in patient group were 4283.7 +/- 1823.7 and 2754.5 +/- 889.3 IU/L, respectively. In the control group, mean arginase activity was 2254.7 +/- 903 IU/L. When pre-, post-operative and control arginase values were compared with each other, the mean activity in pre-operative activity was significantly different from the post-operative and control values (p < 0.001). In the patient group, the mean levels of pre- and post-operative iNOS were 2.84 +/- 1.16 and 1.99 +/- 0.78 IU/ml, respectively. The difference was statistically significant (p = 0.007). Similarly, post-operative and control values were not significantly different (p > 0.05). CONCLUSION: The results of the present study supports that L-arginine:NO pathway may be key the participant in the pathogenesis of chronic adenotonsillar disease; arginase and iNOS activities are altered in children with adenotonsillar hypertrophy and this alteration improves after tonsillectomy.     

Why do palatine tonsils grow back after partial tonsillectomy in children?

Within the last decade, adenoidectomy with partial tonsillectomy has been revived in children with obstructive sleep-disordered breathing caused by adenotonsillar hyperplasia, generating debate about remaining tonsillar tissue regrowth. The study examined potential risk factors of the regrowth. Prospective, nonrandomised, case series feasibility study of children meeting the criteria for palatine tonsils regrowth after partial tonsillectomy performed in patients with obstructive sleep-related breathing disorder was carried out. Out of 793 operated children, 294 after adenoidectomy and 373 after adenotonsillotomy were followed up for 4 years in 12-month intervals. In 27 children after adenotonsillotomy, regrowth of tonsillar tissue was observed. In 22 individuals after adenoidectomy alone, hyperplasia of palatine tonsils was noted. The children had bacterial cultures of pharyngeal smears and blood samples tested for anti-streptolysin O, C-reactive protein and total IgE. Caregivers completed a questionnaire reporting on: their child’s breathing after surgery; frequency, severity and treatment of upper respiratory tract infections; diet; family history of adenoidal and/or tonsillar hyperplasia; and history of allergy. As controls, 272 participants after adenoidectomy alone and 346 after adenotonsillotomy were examined. The amount of sugar in the diet and the incidence of upper respiratory tract infections after surgery differed between the groups of patients and controls. Other differences were insignificant. The tonsillar tissue remaining after partial tonsillectomy in children has a remarkable tendency to grow back, related to a diet abundant in sugar and numerous upper respiratory tract infections. Tonsillar regrowth was age related and occurred most frequently in individuals older than 7 years.     

Cellular immune response of adenoidal and tonsillar lymphocytes to the P6 outer membrane protein of non-typeable Haemophilus influenzae and its relation to otitis media.

Cellular immune responses to the P6 outer membrane protein of non-typeable Haemophilus influenzae (NTHi) were determined in vitro by measuring immunoglobulin (Ig) secreting cells and lymphocyte proliferation in adenoidal and tonsillar lymphocytes from 19 children. Preliminary tests showed that P6 did not stimulate naive cells such as cord blood lymphocytes, but did stimulate sensitized cells in adenoids and tonsils. Cellular proliferation was significantly higher in adenoidal lymphocytes than in tonsillar lymphocytes (median: quadratile of stimulation index = 3.7:2.3-5.5 vs. 1.2:1.0-2.1, p < 0.02). A comparison between children with or without otitis media revealed that proliferative responses to P6 of adenoidal lymphocytes from children with otitis media were significantly decreased (2.0:1.8-3.6 vs. 3.7:2.3-5.5, p < 0.04). P6-specific antibody secreting cells were identified in a total of 14 adenoids and the number of cells secreting IgA was decreased in the otitis media group compared to controls (median: quadratile/10(6) cells = 435:359-499 vs. 755:593-1870, p < 0.05). Cultivation with P6 stimulated IgA secretion in children without otitis media, while no response was seen in children with otitis media (median: quadratile/10(6) cells = 1323:915-2410 vs. 2240:1900-2830, p < 0.02). These preliminary data demonstrate that lymphocytes from adenoids and tonsils recognize P6 as a specific antigen and that the adenoid is the more reactive of the two organs. Impaired P6-specific cellular immune responses of adenoids in children with otitis media may explain the recurrent nature of otitis media due to NTHi in the otitis prone population.     

Nasal nitric oxide in children with adenoidal hypertrophy: A preliminary study

Objective

Nasal nitric oxide, a mediator involved in upper airway inflammation, is impaired in children with allergic rhinitis and rhinosinusitis. Normal values are 200-450 parts per billion, but no data are available concerning its levels in children with adenoidal obstruction, predisposing to chronic nasosinusal inflammation. This study aimed to: (1) measure nasal nitric oxide levels in non-allergic children with adenoidal hypertrophy and (2) assess its possible relationship with the degree of adenoidal hypertrophy and other variable (gender, age, body max index, passive smoking exposure, recurrent acute otitis media, recurrent respiratory infections, and hypertrophy of nasal turbinates).

Methods

Eighty-one children with suspected adenoidal hypertrophy underwent nasal fibroendoscopy to assess the degree of adenoidal hypertrophy, and nasal nitric oxide on-line measurements by means of a dedicated chemiluminescence analyser.

Results

Nasal nitric oxide was successfully measured in 35 patients, most of whom had levels >450 parts per billion; the values were significantly higher (p = 0.031) in children with non-obstructive adenoids. There was no significant correlation with any other variable.

Conclusions

Preliminary data show above-normal nasal nitric oxide levels in children with adenoidal hypertrophy, especially those with non-obstructive adenoids. This suggests nitric oxide involvement in recurrent nasopharyngeal inflammation due to adenoidal hypertrophy.     

Oxidants and antioxidants in tonsillar and adenoidal tissue in chronic adenotonsillitis and adenotonsillar hypertrophy in children

OBJECTIVE: The aim of the study is to determine the possible role of oxidants and antioxidants in the pathogenesis of chronic adenotonsillitis and adenotonsillar hypertrophy in children. PATIENTS AND METHODS: The children were divided into infection and hypertrophy groups, which were comparable according to age and gender distribution. The infection group was consisted of 20 children with the diagnosis of chronic adenotonsillitis and the hypertrophy group was made up of 19 children with adenotonsillar hypertrophy to whom adenotonsillectomy was performed. Preoperative blood levels of erythrocyte MDA, serum MDA, erythrocyte catalase and serum catalase, and adenoidal and tonsillar tissue levels of MDA and catalase were studied. RESULTS: There were significant increase in tonsil MDA, adenoid MDA, tonsil catalase and adenoid catalase levels in infection group (p<0.05). CONCLUSION: Oxidants and antioxidants are found to have an important role in the pathogenesis of adenotonsillar hypertrophy and chronic adenotonsillitis. These findings strengthen the hypothesis that indicates adenotonsillar hypertrophy and chronic adenotonsillitis are different diseases of the same tissues.     

The incidence of adenoidal regrowth after adenoidectomy and its effect on persistent nasal symptoms

Objective of the study is to evaluate the effectiveness of adenoidectomy for children, to asses the rates of adenoidal regrowth and find out if the regrowth of adenoidal tissue affects persistent nasal symptoms post-surgery. A prospective study was carried out in the period of 2005–2007. The inclusion criteria for patients in the study were hypertrophic adenoid tissue and moderate or severe persistent nasal obstruction. One hundred and fifty children had undergone an adenoidectomy using consistent technique and visual control. Medium-term follow-up results were conducted 12–24 months (the mean follow-up period was 17.1 months) post-surgery, performing transnasal fibroscopy and completing the questionnaire. A total of 104 (69.3%) out of 150 patients polled. Children’s parents answered the questions that were used for the subjective assessment of symptoms and to ascertain the history of the patient’s nasal obstruction and upper respiratory tract infection prior to surgery. The age range was from 3 to 15, of which, 68 (65.3%) of them had undergone a transnasal fibroscopy. There was a significant reduction in symptoms that were displayed by children prior to the operation: there were 5.8% patients with nasal obstruction after the surgery, while incidences of upper airway infections dropped from 79.8 to 7.7% after surgery (P < 0.001). Eighty-six (82.7%) parents considered their child’s well-being as “having improved” and they were “satisfied” with the results. Transnasal fibroscopy examinations identified some regrowth of adenoidal tissue in 13 cases (19.1%), with only 3 cases demonstrating adenoidal regrowth to grade 1. Adenoidal regrowth was correlative with the age of the patients (P = 0.048) and to numerous postoperative treatment with antibiotics (P = 0.032). Adenoids rarely regrow after surgery and where there were traces of adenoidal tissue, it did not manifest clinically. Nasal obstruction after the adenoidectomy is rhinogenic origin, not the cause of enlarged adenoids. Adenoidal regrowth more often occurs in children younger than five years old and in those patients who were treated postoperatively with antibiotics on numerous occasions.     

Helicobacter pylori and tonsillectomy

Tonsillar tissue is a component of mucosa-associated lymphoid tissue (MALT), which has evolved to protect vulnerable mucosal surfaces. Helicobacter pylori, implicated as an aetiological factor in duodenal ulcers and gastritis, induces the appearance of lymphoid aggregates (MALT) in the stomach. This organism is cytotoxic via a nitric oxide synthase cascade. The possibility that tonsillar tissue processes Helicobacter pylori or that Helicobacter pylori can colonize the palatine tonsils is explored. The study design was that of a prospective study. We determined if Helicobacter pylori (i) forms part of the normal microenvironment of the tonsil, (ii) plays a role in the pathogenesis of tonsillitis and (iii) is associated with increased expression of inducible nitric oxide synthase (iNOS) in macrophages of the tonsil. Serology for Helicobacter pylori was performed on 50 patients undergoing tonsillectomy. Tonsillar specimens were monitored for urease activity by CLO test (a sealed plastic slide holding an agar gel, which contains urea and detects the urease enzyme of Helicobacter pylori), and immunocytochemically probed for Helicobacter pylori and iNOS expression. The mean age of this patient group was 17.2 years (3-36 years). Fourteen (28%) were sero-positive for Helicobacter pylori but no evidence of this pathogen was found in any tonsillar specimen. The number of macrophages staining for iNOS, per field, under a magnification of x40, was increased in sero-positive patients (13.3 +/- 1.3 versus 9.9 +/- 0.7; P = 0.01). Helicobacter pylori does not appear to colonize the tonsil. We believe that Helicobacter pylori primes the tonsils by inducing macrophage iNOS expression. The higher expression in sero-positive patients is a reflection of a pro-inflammatory reaction to Helicobacter pylori that is both local and systemic.     

儿童腺样体肥大与分泌性中耳炎的关系研究

目的探讨腺样体肥大儿童中分泌性中耳炎发病情况及其影响因素。方法258例住院手术治疗的腺样体肥大的儿童,均常规进行病史采集、鼻咽侧位片、声导抗检查;对部分患儿进行鼻内镜检查录像,单盲评估腺样体肥大程度及其与咽鼓管咽口的关系。统计分析分泌性中耳炎发生率及其影响因素。结果在258病例中经声导抗检查证实合并分泌性中耳炎者108例（41.9％）,而病史中有明确听力减退主诉者仅27例（10.5％）;对合并和未合并分泌性中耳炎病例的相关影响因素统计分析发现,患儿性别、病程长短、腭扁桃体大小等因素对分泌性中耳炎发病无明显影响,低龄患儿、腺样体过度肥大、腺样体与咽鼓管园枕或咽口关系密切者发生分泌性中耳炎可能性大,多元回归分析证明其中影响最显著的因素是腺样体与咽鼓管园枕或咽口关系密切程度。结论有必要对所有腺样体肥大患儿常规进行听力学检查,以确认或除外分泌性中耳炎诊断。低龄患儿、腺样体过度肥大或与咽鼓管园枕及咽口关系密切是分泌性中耳炎的促发因素。     

扁桃体、腺样体切除术对语音及嗓音影响研究进展

扁桃体、腺样体肥大是临床上最常见的疾病之一,儿童期多表现为腺体增生与肥大,成人期多表现为炎性改变。扁桃体、腺样体切除术作为扁桃体、腺样体肥大常规治疗手段,二者切除后人体鼻腔、咽腔及喉腔的声道形状发生改变,导致患者讲话时气流改变,进而使语音及各类嗓音参数值变化。目前,随着二者肥大发病率和检出率的增高,作为其最主要的治疗手段,扁桃体、腺样体切除术对语音及嗓音影响评估的临床指导意义亦与日俱增。现就扁桃体、腺样体切除术对语音及嗓音影响的机制进行综述。     

阻塞性睡眠呼吸暂停低通气综合征手术治疗对儿童记忆的影响

目的探讨儿童阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea hypopnea syndrome,OSAHS）手术治疗对儿童记忆的影响.方法对80例腺样体肥大合并OSAHS儿童手术前后进行韦氏记忆量表检测、多导睡眠描记（polysomnography,PSG）监测,结果与60例腺样体或扁桃体肥大但不伴有OSAHS的儿童进行比较.结果 80例患儿记忆商（MQ）及各分项记忆指标术前均低于术后,有非常显著性差异（P＜0.01）;术后的各分项记忆指标虽然亦低于对照组,但已无统计学差异（P＞0.05）.结论儿童OSAHS手术治疗有助于改善儿童的短时记忆.     

Altered dipeptidyl peptidase IV and prolyl endopeptidase activities in chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia

Objective

To analyse peptidase activities in the removed tonsils and adenoids from patients with chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia.

Methods

We have analyzed 48 tissue samples from patients undergoing tonsillectomy and adenoidectomy for chronic tonsillitis, tonsillar hyperplasia or adenoid hyperplasia. Tonsillectomy and adenoidectomy samples were collected and frozen for later enzyme analysis. The catalytic activity of a pool of peptidases (dipeptidyl peptidase IV, prolyl endopeptidase, aminopeptidase A, aminopeptidase N, aspartyl aminopeptidase, aminopeptidase B, neutral endopeptidase, pyroglutamyl peptidase I, puromycin-sensitive aminopeptidase and cystinyl aminopeptidase) was measured fluorometrically.

Results

The activity of prolyl endopeptidase was higher in tonsillar hyperplasia and adenoid hyperplasia than in chronic tonsillitis. On the contrary, dipeptidyl peptidase IV activity was higher in chronic tonsillitis than in hypertrophic tissues. When data were stratified by age and gender, dipeptidyl peptidase IV was also found to be more active in adult and male chronic tonsillitis tissues. Inversely, dipeptidyl peptidase IV activity was higher in tissues of females with tonsillar hyperplasia.

Conclusions

These data indicate the involvement of dipeptidyl peptidase IV and prolyl endopeptidase in the mechanisms underlying chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia.     

Variations of salivary dismutase superoxide in tonsillar infection

The antioxidant effect of superoxido dismutase in saliva was measured in children bearing of tonsillar hypertrophy, recidivant tonsillitis or peritonsillar abscess. These levels were compared to those detected on tonsillar tissue obtained from tonsillectomy (p < 0.001). Although salivary SOD concentration in children with tonsillar infection was higher than hypertrophy, there was not a significative correlation to tonsillar value of the enzyme (R2 = 0.2276), so we can not accept a predictive value for salivary SOD of tonsillar suffering and, eventually, of tonsillectomy.     

Alteration of adenoid tissue alkaline and acid phosphatase in children with secretory otitis media

OBJECTIVE: The role of pharyngeal lymphoid tissue in etiopathogenesis of secretory otitis is not yet defined. The influence of tonsillar and adenoid mass, weight, obstruction of naspharyngeal orrifitium, bacterial reservoire or some immunological events are of scientific interest. Tissue nonspecific alkaline phosphatase (TNAP) and acid phosphatase (ACP) are enzymes detected in lymphoid tissue, TNAP as characteristic of B cells, ACP as a characteristic of macrophages and folucullardentritic cells. These enzymes interfere in cell metabolism by removing 5' phosphate group from nucleotides and proteins. Specific activity and kinetic properties were studied in palatinal tonsils and adenoids of children with secretory otitis (OME) and compared with children with recurrent tonsillitis without ear involvement. METHOD: Adenoid and tonsillar tissue of l7 children with OME and 30 children with recurrent tonsillitis were subjected to biochemical investigation using method of releasing of p-nitrophenol from p-nitrophenylphosphate (pNPP). Kinetic parameters as Michaelis-Menten constant were calculated by non-linear regression estimation method. RESULTS: Specific activity of adenoid alkaline phosphatase was lower in children with OME in relation to children with recurrent tonsillitis (t=5.733507, p<0.01). Specific activity of adenoid acid phosphatase was also lower in children with OME (t=3.655456, p<0.01). pH optimum for both enzymes was the same in these two groups of children. Michaelis-Menten constant for both enzymes was significantly higher in adenoid of children with OME than in children with recurrent tonsillitis suggesting lower enzyme affinity for the substrate. CONCLUSION: Differences in specific activities and kinetic properties of adenoid alkaline and acid phosphatases between children with OME and children with recurrent tonsillitis without OME were verified in this study. The results of the study are not able to explain the alteration of alkaline and acid phosphatase characteristics but could point to some possible and specific role of nasopharyngeal lymphoid tissue in pathogenesis of secretary otitis.     

Radiofrequency volume tissue reduction of the tonsils: case report and histopathologic findings

Innovative new techniques to resect tonsillar tissue have been described in the recent literature. We report the case of a patient who underwent volume reduction of tonsillar tissue by radiofrequency energy under local anesthesia in an office setting. Treatment resulted in a reduction of tonsillar size with minimal pain, which can be attributed to the avoidance of mucosal interruption. The patient subsequently underwent standard tonsillectomy, which allowed us to examine the histopathology of the tissue that was treated with radiofrequency. In doing so, we noted an absence of fibrosis and preservation of normal histologic architecture. We conclude that performing volume reduction of tonsillar tissue by applying radiofrequency energy to the stroma of the tonsils without temperature control results in objective improvement in airway size with minimal effects on the histopathology of the tonsillar stroma. Mucosa-sparing tonsillar reduction may be a preferable alternative to other techniques of tonsillar reduction, especially for young children, who would experience a nearly pain-free procedure.     

Comparison of Helicobacter pylori colonization on the tonsillar surface versus tonsillar core tissue as determined by the CLO test

We conducted a prospective study to determine the correlation between the presence or absence of Helicobacter pylori on the tonsillar surface and in the tonsillar core as determined by the Campylobacter-like organism (CLO) rapid urease enzyme test. Our study population was made up of 55 patients who underwent adenoidectomy, tonsillectomy, or both from December 2002 through April 2003 at Khalili Hospital in Shiraz, Iran. Of these 55 patients, 45 (82%) were positive and 10 (18%) were negative for H pylori colonization as determined by CLO testing. Analysis of samples obtained from individual patients revealed differences in H pylori colonization between tonsillar surface samples and the core tissue samples. Of 106 tonsils obtained from 53 patients who underwent adenotonsillectomy or tonsillectomy, H pylori was found on 56 tonsillar surface samples (53%) and 24 tonsillar core samples (23%); only 13 tonsils (12%) contained H pylori both on the surface and in the core. We conclude that a surface swab is neither specific nor sensitive as an indicator of the presence or absence of H. pylori colonization in tonsillar core tissue.     

Acoustic reflectance of pharyngeal structures in children

The aim of this study was to examine whether Eccovision Reflectance Pharyngometer could assess the anatomical structure of the upper airway in young children. Secondary aims were to assess changes in pharyngeal volume in children with tonsillar (Group A, n=13) and adenoidal hypertrophy (Group B, n=17) at pre- and post- surgical procedures, respectively and further compare them to children who underwent myringotomy (Control Group C, n=10). In all 40 children (aged 3-9 years, median 6 years) enrolled in this pilot prospective study, six recordings (equally dispersed at pre- and 3 month post- operation per subject) of the pharyngeal cavity along with demographic (age, gender), somatic (standing and sitting height, body weight, head and neck circumference) and anatomic (bimaxilliary and bregma) characteristics, were captured. No significant intra-subject variability was noted within the multiple measurements of the pharyngeal volume at pre- as well as post-incision (ANOVA, P>0.1) in all groups. However, in Group A there was a marked increase from pre- to post-pharyngeal volumes in males (P=0.007), which was not observed in females (P=0.13). In Group B pharyngeal volumes decreased from pre- to post- in both males (P=0.87) and females (P=0.34). On the contrary, in Group C there was no change in pharyngeal volumes. These findings contradicted the visual evaluation of the size of the removed tonsillar and/or adenoidal mass in the first two groups and thus suggested that Eccovision Pharyngometer does not reliably assess pharyngeal volumes in a pediatric population.     

Occult tonsillar carcinoma in the unknown primary

Objectives: Evaluate effectiveness of routine tonsillectomy in the assessment of patients with squamous cell carcinoma of the neck of unknown primary, and evaluate outcomes of this group compared with patients without a primary identified initially. Study Design: A retrospective review of the medical records of 37 patients presenting with an unknown primary tumor over a 10-year period. Methods: Charts were reviewed for age and sex of patients, methods of evaluation and diagnosis, sites of tissues obtained on biopsy, N stage of disease, and presence of extracapsular spread. Recurrence and survival data were collected over a mean follow-up period of 34 months. Results: All primary lesions discovered through pathologic evaluation arose from the tonsil (9/9), and all were detected in patients undergoing tonsillectomy in conjunction with direct laryngoscopy. None of the patients (0/9) with occult tonsillar carcinoma have had recurrence, in contrast to 60% (15/25) of remaining patients. Patients with tonsillar primary lesions demonstrated less extracapsular spread of disease (25%) than patients without tonsillar primaries (67%), despite similar N staging within the two groups. Conclusions: Occult tonsillar carcinoma accounts for the unknown primary more frequently than was previously recognized. Bilateral tonsillectomy is recommended to increase the detection yield and to capture the rare case of bilateral disease. A lower incidence of extracapsular spread and reduced recurrence rates in patients with unknown primary tumors presenting as occult tonsillar carcinoma may contribute to the improved prognosis observed in this group. Laryngoscope, 108:1605–1610, 1998