Human papillomavirus in sinonasal papillomas and squamous cell carcinoma.

The diagnostic and prognostic relevance of human papillomavirus (HPV) types 6, 11, 16, and 18 in squamous papilloma, inverted papilloma, and squamous carcinoma of the sinonasal epithelium was examined using the polymerase chain reaction (PCR) technique. Four (15%) of 26 squamous papillomas, 7 (24%) of 29 inverted papillomas, and 1 (4%) of 24 squamous carcinomas were positive for HPV when examined using the PCR amplification technique. Human papillomavirus 6 was present in 5 specimens (3 squamous and 2 inverted papillomas); HPV-11 was present in 6 specimens (1 squamous and 5 inverted papillomas); and HPV-18 was present in 1 of 24 squamous carcinomas. HPV-16 was not identified in any specimen. The proportion of tissue samples showing HPV presence, and the association of HPV types 6 and 11 with benign lesions and HPV-18 with malignant lesions, are both in accord with findings from prior investigations. Two major questions regarding nasal papilloma are the probability for lesion recurrence after surgical excision and the risk for malignant transformation. There is no unanimity of opinion regarding the prognostic value of histopathologic dysplasia to forecast these outcomes. HPV is etiologically related to a subset of sinonasal papillomas and squamous carcinoma, and those with benign and malignant clinical course are separable on basis of HPV type. Because of the paucity of these nasal lesions, a multi-institutional prospective collaborative study is the ideal way to address these questions.     

Detection of human papillomavirus genome in nasolaryngeal papillomas using digoxigenin labeled DNA probes

It is being reported that human papillomavirus (HPV) has been implicated in the pathogenesis of various neoplastic lesions of the genital organs. To investigate the etiological role of HPV and its types in nasolaryngeal papillomas, we retrospectively analyzed HPV genomes by nucleic acid hybridization methods; for detecting DNA and mRNA, we employed the recently developed nonradioactive (digoxigenin labeled) DNA probes and compared the results by radioisotope methods. In total, 43 cases of papillomatous lesions were examined. They were verruca vulgaris of the nasal vestibule (Nr = 2), nasal inverted papilloma (IP, Nr = 26), and laryngeal papilloma (Nr = 15). HPV types examined were type 2, 6, 11, 16 and 18. Two cases of verruca vulgaris were shown to contain HPV-2 DNA and its mRNA by in situ hybridization. HPV-11 DNA was detected in 3 cases (12%) of nasal inverted papilloma whereas HPV-16 was detected in 1 case (4%); the latter case was associated with squamous cell carcinoma. These results suggest that HPV may be implicated in the development of IP, and HPV-16 may play an important role in the malignant transformation of IP. In the cases of multiple laryngeal papilloma (Nr = 8, one juvenile type and 7 adult type), either HPV-6 or HPV-11 was detected at the high rate (6/8, 75%). The presence of the HPV genomes provides strong evidence for the HPV etiology of these laryngeal papillomas. Whereas in the cases of adult single laryngeal papilloma (Nr = 7), HPV was not detected. Technically, the sensitivity of digoxigenin (DIG) labeled DNA probe was almost same as 35S labeled probe by dot blot hybridization, thus we applied DIG labeled probe to Southern blot hybridization with low background. By in situ hybridization using digoxigenin labeled probes, the rates of HPV detection were almost equal to those by 35S labeled probes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human papilloma virus and p53 expression in carcinomas associated with sinonasal papillomas: a Danish Epidemiological study 1980-1998

OBJECTIVES: To determine a putative role and relation between human papilloma virus (HPV) and p53 in the etiology of sinonasal carcinomas associated with papillomas. STUDY DESIGN: The study group consists of all patients with sinonasal carcinomas associated with papillomas diagnosed in Denmark from 1980 to 1998. After reviewing our national pathological files, tumor tissues from 36 patients were collected, comprising 15% of the total cases of sinonasal carcinomas. In 35 cases a squamous cell carcinoma was demonstrated and in one case an adenocarcinoma was evident. Inverted papilloma was associated with carcinoma in 31 cases and exophytic papillomas in 5 cases. The material was investigated for HPV using polymerase chain reaction analyses with two sets of consensus primers (GP5+/GP6+ and MY09/MY11). The HPV-positive cases were submitted to dot-blot hybridization to establish the HPV type. Using immunohistochemistry, the p53 expression was determined. A p53 overexpression is defined as positive staining in 10% or more of the tumor cells. RESULTS: Among 30 examined cases of carcinomas associated with inverted papillomas, 4 cases were HPV-positive (13%). P53 overexpression was not shown among the HPV-positive cases, whereas p53 overexpression was seen in 21 of the 24 (88%) examined HPV-negative cases. Among the 5 carcinomas associated with exophytic papillomas, HPV was demonstrated together with p53 overexpression in 3 cases (60%). In addition, one case more was with p53 overexpression. CONCLUSION: An inverse relation between HPV and p53 overexpression in sinonasal carcinomas associated with inverted papillomas appears to have been demonstrated. HPV and p53 might also have an etiological role among the carcinomas associated with exophytic papillomas.     

Human papillomavirus and infiltration of CD8- and Foxp3-positive immune cells in sinonasal inverted papillomas

Abstract

Background: Sinonasal inverted papilloma (IP) is a benign tumor with a high risk of local recurrence and a potential to malignify and Human papillomavirus (HPV) has been suggested an etiological factor. p16INK4a (p16) overexpression is considered a surrogate marker for HPV, but whether p16 and HPV correlate to IP is uncertain. Besides, a prognostic role of tumor infiltrating lymphocytes (TILs) are observed in many tumors, however their role in IP is sparsely studied.

Aims/objectives: We hence analyzed IPs for the presence and the prognostic role of HPV and p16 overexpression together with CD8+ and FoxP3+ TILs in a population-based study.

Material and methods: 98 IP patients diagnosed 2001–2010 were identified from the Swedish Cancer Registry and analyzed for HPV by PCR and p16, CD8 and FoxP3 was by immunohistochemistry.

Results: In total, 12.2% of the IPs were HPV-positive (nine HPV-11, two HPV-6 and one HPV-45). Patients with HPV-positive lesions were younger (p?=?.003) and tended to present with more dysplasia. No correlation was observed between TILs and prognosis.

Conclusions and significance: Our data suggests that patients with HPV-positive IPs present with different clinical characteristics, suggesting possibly different disease entities. Moreover, recurrences may occur >5?years, which should be considered in the follow-up.     

Human papillomavirus (HPV) in sinonasal papillomas: A study of 78 cases using in situ hybridization and polymerase chain reaction

To determine the role of human papillomavirus (HPV) in the etiology of sinonasal papillomas, 57 inverted papillomas including 5 cases associated with carcinomas, 16 exophytic papillomas, and 5 cases of columnar cell papillomas were examined for the presence of HPV DNA by in situ hybridization and polymerase chain reaction (PCR). The genetic studies were performed on the formalin-fixed, paraffin-embedded material. In only 6% of the 52 benign inverted papillomas was HPV DNA identified, whereas 69% of the exophytic papillomas were infected by HPV DNA. In none of the 5 cases with columnar cell papillomas could HPV be demonstrated. HPV 6/11 was identified in all of these HPV-positive cases. In the carcinoma area, HPV was detected in 2 (1 HPV 6/11 and 1 HPV 18) of the 5 inverted papillomas associated with carcinomas. The findings confirm the presence of HPV DNA in sinonasal papillomas. The results also indicate that HPV 6/11 may be involved in the pathogenesis of, solely, exophytic papillomas. We found that in situ hybridization and PCR seem equally sensitive in detecting HPV in sinonasal papillomas.     

In situ hybridization and immunohistochemical study of human papillomavirus infection in adult laryngeal papillomas

Routinely processed paraffin sections from 20 patients with adult laryngeal papillomas were examined for the presence of human papillomavirus type 11 (HPV-11) DNA and its specific mRNA by in situ hybridization methods using 35S-labeled RNA probes. Immunohistochemical techniques were also used to identify papillomavirus genus-specific common antigen (pgs-antigen). HPV-11 DNA signals and/or papillomavirus genus-specific common antigen were detected in all eight samples of multiple laryngeal papilloma. On the other hand, in 12 samples of single laryngeal papilloma, neither papillomavirus genus-specific common antigen nor HPV-11 DNA were detected. Four patients were positive for both HPV-11 DNA and pgs-antigen. In three of these four patients, HPV-11 mRNA signals were also detected. These results provided direct evidence of the association of HPV and adult multiple laryngeal papilloma.     

Diagnosis and treatment modalities in sinonasal inverted papillomas

BACKGROUND: Today, etiology and pathogenesis of sinunasal inverted papillomas (IP) remain unknown. Surgical approaches and extension of surgical resections are still controversial. PATIENTS AND METHODS: In a retrospective study we reviewed the charts of 90 patients with sinunasal IP. Using external (n = 78) or endonasal (n = 12) approaches the tumors were completely resected in all cases. 57 cases were investigated for human papilloma virus (HPV) by immunohistochemistry. RESULTS: 60% of IP extended beyond one single paranasal sinus or the nasal cavity. 7% infiltrated adjacent anatomical structures (subcutis, orbit, anterior skull base). The recurrence rate was 19% after a mean interval of 8.2 month. Associated malignancy was found in 7 cases (7.7%). HPV was detected in 9% of IP. Postoperative complaints were noticed by 27% of endonasal and 35% of trans-facial operated patients. CONCLUSIONS: Because of the advanced tumor stage in the majority of cases, usually a radical trans-facial surgical excision of IP is required. Endonasal approaches are feasible in selected cases, but surgery has to be more extensive compared to surgery for sinunasal polyposis. In the literature and in our experience IP is rarely associated with carcinoma (10% in literature) and the incidence of malignancy is not increased in recurrent IP. Using PCR, the prevalence of HPV ranges from 7 to 69% in the literature. Our immunohistochemical results support a rather low prevalence of HPV in IP.     

Long-term results of endonasal sinus surgery in sinonasal papillomas

OBJECTIVE: To assess the value of endonasal sinus surgery in the management of sinonasal papillomas. STUDY DESIGN: Retrospective study including 43 patients operated on for sinonasal papilloma in a long-term follow-up. METHODS: In 26 cases (60%) an endonasal approach, in eight cases (19%) an external approach, and in four cases (9%) a combined procedure was performed to remove these tumors. Five septal lesions (12%) were resected under direct vision. The original sections and charts of all patients were reviewed to assess clinical data. Follow-up information was available for 42 of our patients (98%) with a mean follow-up of 62 months. RESULTS: Histologic examination revealed 34 cases of inverted papilloma (79%), five cases of exophytic papilloma (12%), and four cases of columnar cell papilloma (9%). Malignancy occurred in 4 of 43 patients (9%), and recurrences developed in 8 of 42 patients (19%). Two of these recurrences happened after endoscopic sinus surgery (two inverted papillomas), three after lateral rhinotomy (three inverted papillomas), one after a combined procedure (one inverted papilloma), and two after simple resection (two exophytic papilloma). CONCLUSIONS: In keeping with our experience, the endonasal endoscopic approach, often in combination with a medial maxillectomy, is favored for the treatment of sinonasal papilloma because of a lower recurrence rate and a better cosmetic result. In some larger tumors and lesions in difficult locations, better visualization can be obtained by a combined external and endonasal approach.     

Treatment outcomes of primary and recurrent inverted papilloma: an analysis of 96 cases

This series was undertaken to investigate the incidence of associated polyps and the recurrence rates of inverted papillomas with, or without, malignancies, as well as the treatment outcomes of the recurred cases. A retrospective study evaluating the pathology, associated polyps, types of operation, recurrence rate after original operation, and surgical outcomes of recurred cases was conducted upon 96 patients diagnosed with inverted papilloma. The overall malignancy rate was 11.5 per cent with synchronous tumours accounting for 9.4 per cent and metachronous for 2.1 per cent. Inflammatory polyps were found in association with inverted papilloma in 21.9 per cent. In cases without malignancies, the recurrence rate after the original conservative procedure was 33.9 per cent, compared to 14.3 per cent after a medial maxillectomy. In cases with malignancies, the recurrence rate after the original surgical procedure was 22.2 per cent. Our study indicates that more aggressive and bolder surgical resection of inverted papilloma should be undertaken as a primary treatment method, or as a treatment for recurrent cases to reduce the recurrence rate of inverted papilloma with, or without, malignancy.     

鼻腔鼻窦内翻性乳头状瘤人类乳头状瘤病毒DNA检测

为了解鼻腔鼻窦内翻性乳头状瘤与人类乳头状瘤病毒（ＨＰＶ）之间的关系，采用聚合酶链反应，对３８例患者的４４个鼻腔鼻窦内翻性乳头状瘤的病理组织蜡块进行ＨＰＶ－ＤＮＡ的检测。结果显示，３８例中３０例患者的３０个瘤组织蜡块呈ＨＰＶ阳性，总感染率为６８．２％，其中３０例次ＨＰＶ１１型阳性（６８．２％），１８例次ＨＰＶ１６型阳性（４０．９％），２例次ＨＰＶ１８型阳性（４．５％），其中１８例ＨＰＶ１１，１６、２     

Human papillomavirus identified by nucleic acid hybridization in concomitant nasal and genital papillomas.

Presence of human papillomavirus (HPV) as the etiologic agent in nearly all upper respiratory tract recurrent papillomas is well-established. The technique of nucleic acid hybridization now allows specific typing of HPV with a high degree of accuracy. This article reports a series of nine consecutive patients treated for nasal papillomas over the past 9 years. Eight of these patients had a personal history of genital papillomas (seven patients) or exposure (one patient). With the use of in situ hybridization and autoradiographic technique on paraffin-embedded tissue sections, HPV RNA type 6/11 was expressed in eight of nine nasal papillomas, and corresponding HPV types were also found in the two cases with which concurrent anogenital papilloma tissue was also available for analysis. Human papillomavirus RNA types 16 and 18 were not detected in any of the specimens. Signals of HPV messenger RNA type 6/11 were stronger in the fungiform areas than in the inverted areas of papillomas.     

Human papillomavirus in laryngeal papillomas and in adjacent normal epithelium

Eleven adults with laryngeal papillomas were studied for the presence of human papillomavirus (HPV) DNA by in situ hybridization. As well as from the papillomas, three additional biopsies were taken from the normal-appearing mucosa as follows: the involved vocal cord, the opposite vocal cord (when the papilloma was unilateral), and from the ventricular fold on the side of the lesion. These normal tissues were analysed by polymerase chain reaction (PCR) to detect HPV DNA. All except one of the 11 papillomas contained HPV DNA; nine were HPV 6/11 DNA positive and one positive for HPV 16 DNA. The normal-appearing laryngeal mucosa harboured HPV DNA in eight out of 11 patients. The present results strongly support the concept that the adult-type laryngeal papilloma is an HPV-induced lesion, mostly due to HPV types 6 and 11. The persistence of HPV DNA in the adjacent normal epithelium is consistent with the frequent recurrence of these lesions.     

Sinonasal papillomas: A report of 82 cases in copenhagen county,including a longitudinal epidemiological and clinical study

The present epidemiological and clinical study comprises 82 patients with sinonasal papillomas diagnosed from 1975 to 1993. Histology showed 58 cases of inverted papillomas including 5 cases of associated carcinoma, 19 cases of exophytic papilloma, and 5 cases of columnar cell papilloma. The incidence of sinonasal papillomas in Copenhagen County was 0.74 per 100,000 inhabitants per year. The inverted and columnar cell papillomas were typically located in the middle meatus with a varying degree of involvement of the adjacent sinuses. The exophytic papillomas were predominantly located multicentrically on the nasal septum. Good results of treatment, especially with regard to inverted papillomas, were not correlated to the aggressiveness of surgery. A lateral rhinotomy with medial maxillectomy was performed as primary surgery in 28 patients. In 50% of these patients there were recurrences. The preliminary results of endonasal endoscopic surgery revealed a high success rate, i.e., no recurrences in 5 cases so far. The septal papillomas were typically resected by a simple endonasal procedure. There were recurrences in 66% of these cases. The midfacial degloving procedure may be advocated instead of or as a supplement to the lateral rhinotomy if the tumor cannot be visualized sufficiently by endoscopy. Smoking may dispose to sinonasal papillomas.     

High incidence of malignant transformation of laryngeal papilloma in Taiwan

OBJECTIVES: Papillomas of the larynx include solitary laryngeal papilloma and recurrent respiratory papillomatosis. This study investigated the incidence of malignant transformation and assessed possible risk factors for laryngeal papillomas. STUDY DESIGN: A prospective, longitudinal study. METHODS: Twenty-six consecutive laryngeal papilloma patients were prospectively studied for 5 or more years, and each patient was periodically examined at 3 to 6 month intervals. A detailed epidemiologic questionnaire was administered at the initial visit. After enrollment, tissue obtained during each laryngeal surgery was examined by polymerase chain reaction assay for human papilloma virus (HPV) and typing. RESULTS: During 237 person-years of follow-up, six new, pathologically confirmed cases of laryngeal carcinoma were ascertained (incidence 2.5/100 person-years), and all were associated with HPV-6 or HPV-11. Malignant transformation revealed no correlation with the following: age less than 3 years at diagnosis, sex, history of tobacco use, history of alcohol consumption, family history of laryngeal cancer, or type of laryngeal papilloma. Laryngeal papilloma without demonstrable HPV DNA was the only significant risk factor for malignant transformation (P < .05). The cumulative risk of malignant transformation in subjects without demonstrable HPV DNA was significantly higher than that in HPV-positive patients (relative risk, 8.0; 95% confidence interval, 1.1-60.3; P = .05). CONCLUSIONS: A relatively high incidence of malignant transformation of laryngeal papilloma was noted in Taiwanese patients. Patients without demonstrable HPV DNA require more frequent follow-up and may benefit from anti-HPV vaccinations.     

Schneiderian papillomas and carcinomas: a retrospective study with special reference to p53 and p16 tumor suppressor gene expression and association with HPV

Schneiderian papillomas are uncommon benign tumors of the sinonasal area. They are prone to local aggressiveness and recurrence, and some undergo malignant progression. We analyzed specimens obtained from 67 Chinese patients who had presented to the ENT department of a regional hospital with biopsy-proven schneiderian papilloma. Seven of these patients had either synchronous or metachronous carcinoma, 1 of whom had pure carcinoma in situ. For each case, we documented the morphology, immunohistochemical expression of tumor suppressor genes p53 and p16, and any association with human papillomavirus (HPV) infection as detected by either polymerase chain reaction or in situ hybridization techniques. We found that severe dysplasia and p53 positivity were strongly associated with malignant progression. Association with HPV was demonstrated in 22 of the 67 patients (33%); the association was strongest among patients with exophytic papillomas and carcinomas. The effect of HPV in papilloma oncogenesis probably begins during the early phase, while other factors are responsible for progression to carcinoma. We conclude that p53-positive, dysplastic schneiderian papillomas warrant aggressive surgical treatment.     

Effect of human papilloma virus expression on clinical course of laryngeal papilloma

Conclusion. Our observations suggest that human papilloma virus (HPV) 6/11 is the main causative agent of laryngeal papilloma and that detection of active HPV DNA expression may be helpful in identifying patients with aggressive recurrent laryngeal papilloma. Objectives. HPV is assumed to be the main causative agent of this disease. We investigated the expression of the entire genotype of HPV in cases of laryngeal papilloma and correlated their expression with the clinical course of the disease. Subjects and methods. Seventy cases of laryngeal papilloma were evaluated for the presence of the HPV genome by in situ hybridization (ISH) using wide-spectrum HPV DNA probe. Specific types of HPV infection were determined by DNA ISH using type-specific HPV DNA probes (HPV 6, 11, 16, 18, 31, 33). Separate analyses were conducted comparing viral types, frequency of recurrences and duration of disease-free periods. Results. We detected HPV DNA in 40 of the 70 laryngeal papilloma cases (57%). In particular, HPV DNA was detected in 75% of the juvenile types. There were significant associations between HPV and laryngeal papilloma (p<0.01). Among the HPV-positive cases, major specific types were HPV 6/11 (97%). Significant associations were also noted between viral expression and clinical course.     

人乳头状瘤病毒与鼻内翻性乳头状瘤的关系

为探讨人乳头状瘤病毒（ＨＰＶ）感染与鼻内翻性乳头状瘤（ＩＰ）发病及其恶变的关系，研究选取组织病理确认为ＩＰ（３６例）和ＩＰ癌变（１６例）的石蜡包埋标本，采用多聚酶链反应（ＰＣＲ）方法对标本进行ＨＰＶ相关ＤＮＡ序列扩增。结果显示：３６例ＩＰ组织有２１例（５８．３％）为ＨＰＶ阳性；１６例ＩＰ癌变组织中有１１例（６８．８％）阳性。经统计学处理，二者间无显著性差异（Ｐ〉０．０５）．提示ＨＰＶ感染在ＩＰ的发     

Relationship of Human Papillomavirus to Schneiderian Papillomas

Objectives/Hypothesis: To classify a large group of Schneiderian papillomas (SPs) into their histologic subtypes and to determine the incidence of human papillomavirus (HPV) in each subtype. Study Design: Pathologic review and polymerase chain reaction–based (PCR-based) examination of archived tissue. Methods: Slides of 114 tumors diagnosed as Schneiderian, inverting, fungiform, or cylindric cell papillomas, or any associated carcinomas, were examined by a head and neck pathologist. Using PCR, consensus primers for the L1 region of HPV were used to determine the presence of HPV in the tumors. This was also performed on normal turbinate control specimens. Results: Eighty-two (78%) were the inverting subtype, 21 (20%) the fungiform subtype, and 2 (2%) the cylindric cell type. Nine tumors were diagnosed as either verrucous or squamous cell carcinoma. Eighty-eight percent of the tumors had DNA of sufficient quality to be amplified using PCR. Of these, 5 of 69 (6.8%) inverting, 17 of 17 (100%) fungiform, and 0 of 2 cylindric cell papillomas were positive for HPV. One of nine (11.1%) cancers was positive for HPV. No normal turbinate tissue contained HPV. HPV types 6b and 11 accounted for all cases of fungiform papillomas. Of the five HPV-positive inverting papillomas, three had HPV type 11 and two had HPV type 16. The single carcinoma containing HPV contained HPV type 18. Conclusions: The histologic subtype of SPs is important, as their etiologies appear to be different. HPV 6b and 11 appear to be involved in all cases of fungiform papillomas but are only rarely involved in cases of inverting or cylindric cell papillomas. HPV 16 may rarely play a role in cases of inverting papillomas, and HPV 16 and 18 may be involved in a subset of cases of carcinomas originating in an inverting papilloma.     

Sinonasal inverted papilloma: rate of recurrence and malignant transformation in 44 operated patients

IntroductionAlthough sinonasal inverted papillomas are benign lesions, they are locally aggressive and have a potential malignant transformation ranging from 5% to 15%, with a high recurrence rate.ObjectiveThe aim of this article is to describe the rate of recurrence and malignant transformation in patients with a diagnosis of inverted papilloma who underwent surgery in a tertiary hospital in São Paulo.MethodsWe performed a retrospective analysis of patients diagnosed with sinonasal papilloma who had undergone surgery in a tertiary hospital in São Paulo, between August 1998 and August 2017. A patient chart review was conducted to assess data of patients’ demographics, tumors characteristics, follow-up appointments, recurrence and malignancy. Inverted papillomas were analyzed and classified under the Krouse staging system.ResultsA total of 69 surgeries were performed in patients with diagnosis of sinonasal papilloma. Inverted papilloma was the most prevalent subtype (49 cases ? 80.33%), followed by exophytic papilloma (6 cases ? 9.84%) and by oncocytic papilloma (6 cases – 9.84%). The recurrence rate was 34.09% for inverted papilloma (15/44) and the mean time of recurrence was 24.6 months. Malignant transformation occurred in 6 patients (13.64%). Three of these patients presented carcinoma in the first surgery and three patients developed carcinoma during the follow-up.ConclusionThe high recurrence rate and malignancy potential allow us to consider inverted papillomas as aggressive tumors. In a tertiary hospital in São Paulo the recurrence rate the mean time to recurrence is 24.6 months. The recurrence after 10 years implies was 34.09% and the need for long-term follow up. It is possible that the high recurrence rate and the high malignant transformation rate we found are due to the large number of tumors discovered at an advanced stage (most of them staged T3 and T4), secondary to poor access to health system, in developing countries.     

Effect of human papilloma virus expression on clinical course of laryngeal papilloma

Conclusion. Our observations suggest that human papilloma virus (HPV) 6/11 is the main causative agent of laryngeal papilloma and that detection of active HPV DNA expression may be helpful in identifying patients with aggressive recurrent laryngeal papilloma. Objectives. HPV is assumed to be the main causative agent of this disease. We investigated the expression of the entire genotype of HPV in cases of laryngeal papilloma and correlated their expression with the clinical course of the disease. Subjects and methods. Seventy cases of laryngeal papilloma were evaluated for the presence of the HPV genome by in situ hybridization (ISH) using wide-spectrum HPV DNA probe. Specific types of HPV infection were determined by DNA ISH using type-specific HPV DNA probes (HPV 6, 11, 16, 18, 31, 33). Separate analyses were conducted comparing viral types, frequency of recurrences and duration of disease-free periods. Results. We detected HPV DNA in 40 of the 70 laryngeal papilloma cases (57%). In particular, HPV DNA was detected in 75% of the juvenile types. There were significant associations between HPV and laryngeal papilloma (p<0.01). Among the HPV-positive cases, major specific types were HPV 6/11 (97%). Significant associations were also noted between viral expression and clinical course.