Wnt pathway, angiogenetic and hormonal markers in sporadic and familial adenomatous polyposis-associated juvenile nasopharyngeal angiofibromas (JNA)

Integrated Molecular and Histological Insights for Targeted Therapies in Mesenchymal Sinonasal Tract Tumors

PURPOSE OF REVIEW

This review aims to provide a comprehensive overview of mesenchymal sinonasal tract tumors (STTs), a distinct subset of STTs. Despite their rarity, mesenchymal STTs represent a unique clinical challenge, characterized by their rarity, often slow progression, and frequently subtle or overlooked symptoms. The complex anatomy of the sinonasal area, which includes critical structures such as the orbit, brain, and cranial nerves, further complicates surgical treatment options. This underscores an urgent need for more advanced and specialized therapeutic approaches.

RECENT FINDINGS

Advancements in molecular diagnostics, particularly in next-generation sequencing, have significantly enhanced our understanding of STTs. Consequently, the World Health Organization has updated its tumor classification to better reflect the distinct histological and molecular profiles of these tumors, as well as to categorize mesenchymal STTs with greater accuracy. The growing understanding of the molecular characteristics of mesenchymal STTs opens new possibilities for targeted therapeutic interventions, marking a significant shift in treatment paradigms. This review article concentrates on mesenchymal STTs, specifically addressing sinonasal tract angiofibroma, sinonasal glomangiopericytoma, biphenotypic sinonasal sarcoma, and skull base chordoma. These entities are marked by unique histopathological and molecular features, which challenge conventional treatment approaches and simultaneously open avenues for novel targeted therapies. Our discussion is geared towards delineating the molecular underpinnings of mesenchymal STTs, with the objective of enhancing therapeutic strategies and addressing the existing shortcomings in the management of these intricate tumors.

Sinonasal Myxoma: A Distinct Entity or a Myxoid Variant of Desmoid Fibromatosis?

Sinonasal myxoma (SNM) is a rare benign mesenchymal tumor that arises in the sinonasal cavity or maxilla and almost exclusively affects young children. Currently, it is considered a specific entity, but its molecular characteristics have not been reported. Lesions diagnosed as SNM and odontogenic myxoma/fibromyxoma (OM/OFM) were identified from the participating institutions, and the clinicopathologic features were recorded. Immunohistochemistry for β-catenin was performed on all cases with available tissue. Next-generation sequencing (NGS) was performed on all SNM cases. Five patients with SNM were identified, including 3 boys and 2 girls with an age range of 20-36 months (mean: 26 months). The tumors were well-defined, centered in the maxillary sinus, surrounded by a rim of woven bone, and composed of a moderately cellular proliferation of spindle cells oriented in intersecting fascicles in a variably myxocollagenous stroma that contained extravasated erythrocytes. Histologically, the tumors resembled myxoid desmoid fibromatosis. Three tested cases showed nuclear expression of β-catenin. In 3 tumors, NGS revealed intragenic deletions of APC exons 5-6, 9 and 15, or 16, respectively, with concurrent loss of the other wild-type copy of APC, predicted to result in biallelic inactivation. The deletions were identical to those that occur in desmoid fibromatosis, and copy-number analysis raised the possibility that they were germline. In addition, one case showed possible deletion of APC exons 12-14, and another case exhibited a CTNNB1 p.S33C mutation. Ten patients with OM/OFM were identified, including 4 women and 6 men (mean age: 42 years). Seven tumors involved the mandible, and 3 the maxilla. Histologically, the tumors differed from SNM, and all cases lacked nuclear expression of β-catenin. These findings suggest that SNM represents a myxoid variant of desmoid fibromatosis that often arises in the maxilla. Because the APC alterations might be germline, genetic testing of the affected patients should be considered.

Inhibition of CK2 Reduces NG2 Expression in Juvenile Angiofibroma

Juvenile angiofibroma (JA) is a rare fibrovascular neoplasm predominately found within the posterior nasal cavity of adolescent males. JA expresses the proteoglycan nerve–glial antigen (NG)2, which crucially determines the migratory capacity of distinct cancer cells. Moreover, it is known that the protein kinase CK2 regulates NG2 gene expression. Therefore, in the present study, we analyzed whether the inhibition of CK2 suppresses NG2-dependent JA cell proliferation and migration. For this purpose, we assessed the expression of NG2 and CK2 in patient-derived JA tissue samples, as well as in patient-derived JA cell cultures by Western blot, immunohistochemistry, flow cytometry and quantitative real-time PCR. The mitochondrial activity, proliferation and migratory capacity of the JA cells were determined by water-soluble tetrazolium (WST)-1, 5-bromo-2′-deoxyuridine (BrdU) and collagen sprouting assays. We found that NG2 and CK2 were expressed in both the JA tissue samples and cell cultures. The treatment of the JA cells with the two CK2 inhibitors, CX-4945 and SGC-CK2-1, significantly reduced NG2 gene and protein expression when compared to the vehicle-treated cells. In addition, the loss of CK2 activity suppressed the JA cell proliferation and migration. These findings indicate that the inhibition of CK2 may represent a promising therapeutic approach for the treatment of NG2-expressing JA.

Pediatric sinonasal and skull base lesions

Pediatric skull base lesions are complex and challenging disorders. Safe and comprehensive management of this diverse group of disorders requires the expertise of an experienced multidisciplinary skull base team. Adult endoscopic skull base surgery has evolved due to technologic and surgical advancements, multidisciplinary team approaches, and continued innovation. Similar principles continue to advance the care delivered to the pediatric population. The approach and management of these lesions varies considerably based on tumor anatomy, pathology, and surgical goals. An understanding of the nuances of skull base reconstruction unique to the pediatric population is critical for successful outcomes.

The Genetic and Molecular Determinants of Juvenile Nasopharyngeal Angiofibroma: A Systematic Review

Objective:

Juvenile nasopharyngeal angiofibroma (JNA) is a rare vascular tumor of unknown etiology. Studies investigating the molecular and genetic determinants of JNA are limited by small sample size and inconsistent approaches. The purpose of this study is to examine all eligible JNA studies in aggregate, applying qualitative analysis to highlight areas of particular relevance, including potential targets for therapeutic intervention.

Methods:

The PubMed, MEDLINE, Embase, Web of Science, Cochrane, and CINAHL databases were screened with inclusion and exclusion criteria applied to all citations. Manuscripts investigating the genetic determinants, histopathogenesis, and heritability of juvenile nasopharyngeal angiofibroma were included. Non-English studies, case reports, and articles focusing on clinical management without original data were excluded. Full text articles were obtained. A qualitative synthesis of data was performed.

Results:

A total of 59 articles met criteria for inclusion. These were divided into 6 categories based on the primary topic or target discussed, (1) steroid hormone receptors, (2) chromosomal abnormalities, (3) growth factors, (4) genetic targets, (5) molecular targets, (6) Wnt cell signaling, and (7) studies that overlapped multiple of the aforementioned categories. Although relatively low n values prevent definitive conclusions to be drawn, a predominance of certain molecular targets such as vascular endothelial growth factor (VEGF) and Wnt/β-catenin pathway intermediaries is apparent.

Conclusions:

Although the etiology of JNA remains elusive, contemporary molecular genetic investigation holds promise for risk stratification and could form the basis of a modernized staging system. A multicenter clinical registry and linked tissue bank would further promote the search for JNA specific biomarkers.

Loss of expression of μ-protocadherin and protocadherin-24 in sporadic and hereditary nonpolyposis colorectal cancers

Colorectal cancer (CRC) is a neoplastic disease in which normal mucosa undergoes a process of malignant transformation due to the progressive accumulation of molecular alterations affecting proto-oncogenes and oncosuppressor genes. Some of these modifications exert their carcinogenic potential by promoting a constitutive activation of the β-catenin signaling proliferation pathway, and when present, loss of cadherin expression also significantly contributes to the same effect. Using a combined approach of molecular and immunohistochemical analysis, we have previously demonstrated that most sporadic CRCs exhibit a down-regulated expression of a cadherin, named μ-protocadherin, that is generally observed in association with a higher proliferation rate and a worse prognosis. The aim of this report was to perform a comparative immunohistochemical assessment of μ-protocadherin and a similar cadherin, named protocadherin-24, in sporadic CRC and hereditary nonpolyposis colorectal cancer. The data obtained put in evidence that double-negative CRCs, lacking both the analyzed protocadherins, are more represented among sporadic tumors, whereas double-positive CRCs, maintaining their expression, exhibit an opposite trend. As expected, loss of protocadherin expression was accompanied by nuclear localization of β-catenin and increased positivity of the Ki-67 proliferation marker. This finding is consistent with the different clinical evolution of the 2 considered CRC sets according to which patients with hereditary nonpolyposis colorectal cancer experience a better prognosis as compared with those affected by a sporadic CRC.

Variable expression of molecular markers in juvenile nasopharyngeal angiofibroma

Background:

Molecular categorisation may explain the wide variation in the clinical characteristics of juvenile nasopharyngeal angiofibroma.

Methods:

Variations in molecular markers in juvenile nasopharyngeal angiofibroma in an Indian population were investigated and compared with global reports.

Results:

Variable molecular marker expression was demonstrated at the regional and global levels. A wide variation in molecular characteristics is evident. Molecular data have been reported for only 11 countries, indicating a clear geographical bias. Only 58 markers have been studied, and most are yet to be validated.

Conclusion:

Research into the molecular epidemiology of juvenile nasopharyngeal angiofibroma is still in its infancy. Although the molecular variation is not well understood, data obtained so far have prompted important research questions. Hence, multicentre collaborative molecular studies are needed to establish the aetiopathogenesis and establish molecular surrogates for clinical characteristics.

Nasopharyngeal Angiofibroma: A Clinical, Histopathological and Immunohistochemical Study of 42 Cases with Emphasis on Stromal Features

Nasopharyngeal angiofibroma is a benign but aggressive tumor of unknown etiology, typically occurring in adolescent males. It is described as a rare neoplasm; however, the prevalence seems to have geographic differences. All cases referred to our head and neck clinical and pathology service were reviewed. Most of the patients presented at an advanced stage. The clinical and radiographic features are presented and discussed. Histologically, the tumor shows a highly vascular fibrous proliferation with characteristic plump, angulated and stellate cells, categorized as fibroblasts. Immunohistochemistry was performed on 42 cases to further elucidate the nature of these cells. The stromal cells expressed vimentin and factor XIIIa, the latter expressed most commonly in the giant stellate cells. Inflammation was almost exclusively present in peripheral subepithelial areas. Mast cells were abundant, even in the absence of other inflammatory cells. Lymphatics were observed principally in peripheral regions. Proliferating cells (Ki-67 reactive) were restricted to endothelial cells.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Nasal juvenile angiofibroma: Current perspectives with emphasis on management

Juvenile angiofibroma is an uncommon, benign, locally aggressive vascular tumor. It is found almost exclusively in young men. Common presenting symptoms include nasal obstruction and epistaxis. More advanced tumors may present with facial swelling and visual or neurological disturbances. The evaluation of patients with juvenile angiofibroma relies on diagnostic imaging. Preoperative biopsy is not recommended. The mainstay of treatment is resection combined with preoperative embolization. Endoscopic surgery is the approach of choice in early stages, whereas, in advanced stages, open or endoscopic approaches are feasible in expert hands. Postoperative radiotherapy (RT) or stereotactic radiosurgery seem valuable in long-term control of juvenile angiofibroma, particularly those that extend to anatomically critical areas unsuitable for complete resection. Chemotherapy and hormone therapy are ineffective. The purpose of the present review was to update current aspects of knowledge related to this rare and challenging disease. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1033-1045, 2017.

CTNNB1 (β-Catenin)-altered Neoplasia: A Review Focusing on Soft Tissue Neoplasms and Parenchymal Lesions of Uncertain Histogenesis

β-catenin (CTNNB1) is a key regulatory molecule of the Wnt signaling pathway, which is important for tissue homeostasis and regulation of cell proliferation, differentiation, and function. Abnormal stabilization and nuclear accumulation of β-catenin as a consequence of missense mutations or alternative molecular mechanisms occurs at a high frequency in a variety of epithelial cancers. In mesenchymal neoplasia, the role of β-catenin has been traditionally considered limited to desmoid-type fibromatosis. However, the spectrum of β-catenin-driven (β-catenin-altered) neoplasia of mesenchymal origin has been steadily widening to include, in addition to desmoid tumors, a variety of benign and intermediate-biology neoplasms of soft tissue (intranodal palisaded myofibroblastoma), head and neck (juvenile nasopharyngeal angiofibroma and sinonasal hemangiopericytoma/glomangiopericytoma), and ovarian (microcystic stromal tumor) origin. In addition, several old and newly reported distinctive site-specific β-catenin-driven parenchymal neoplasms of uncertain histogenesis have been well characterized in recent studies, including solid-pseudopapillary neoplasm of the pancreas and its recently described ovarian counterpart, sclerosing hemangioma of lung and calcifying nested stromal-epithelial tumor of the liver. This review addresses the most relevant pathobiological and differential diagnostic aspects of β-catenin-altered neoplasms with emphasis on site-specific histologic and biological variations. In addition, the morphologic overlap and analogy as well as distinctness between these uncommon tumors will be presented and discussed. Furthermore, a note is made on association of some of these lesions with hereditary tumor syndromes, in particular with the familial adenomatous polyposis coli.

Expression of vascular endothelial growth factor in Juvenile Angiofibroma

OBJECTIVE

To examine Juvenile Angiofibroma (JA) tissue for expression of vascular endothelial growth factor (VEGF), and to explore its relationship with puberty status, stage, recurrence and the intraoperative blood loss.

METHODS

Retrospective cohort study of 36 histologically proven cases of JA. Minimum follow up period was 3 years. VEGF expression on tumor cells assessed by immunohistochemistry and graded on two criteria--percentage of cells expressing positivity and the intensity of positivity. These two parameters assessed for impact on puberty status, stage, recurrence, and blood loss.

RESULTS

VEGF expression noted on the tumor endothelial cells in 36/36, and on the tumor stromal cells in 34/36. The percentage of cells expressing VEGF and the intensity of expression were not significantly related to puberty status, tumor stage, recurrence, or intra-operative blood loss (p values 0.3-1.0).

CONCLUSION

VEGF expression is near universal in JA. Such expression is independent of puberty status and stage, and does not impact on intra operative blood loss and recurrence.

The presence of tumor-infiltrating IL-17-producing cells in juvenile nasopharyngeal angiofibroma tumor microenvironment is a poor prognostic factor

BACKGROUND

Although juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor histologically, it demonstrates aggressive propensity of locally destructive growth causing bone erosion. The patients with JNA remain high recurrence rate after surgical excision. Th17 cells secrete the proinflammatory cytokine interleukin-17 (IL-17), and play an important role in carcinogenesis and tumor progression. So far, no studies have focused on the significance of IL-17-producing cells in the JNA tumor microenvironment. The current study was designed to investigate the localization and level of tumor-infiltrating IL-17-producing cells in JNA microenvironment. The presence and number of IL-17-producing cells were further analyzed for a possible association with clinicopathological features and disease outcome.

MATERIALS AND METHODS

Immunohistochemistry was used to analyze the expression of IL-17 in a tissue microarray from 70 patients with JNA and 10 control subjects. Correlations between the levels of IL-17 expression and clinicopathologic variables, as well as tumor recurrence, were assessed.

RESULTS

In vessels, the IL-17-producing cells were identified in pericytes and irregular smooth muscle cells, but the matured vascular endothelial cells showed no IL-17 reactivity. The expression of IL-17 in stromal cells was concentrated in the less differentiated and plump cells that contained a central hypochromatic nucleus and single small nucleolus. Chi-square test showed that tumor stage (p=0.09), operation history (p=0.828), operation approach (p=0.159), and volume of intraoperative hemorrhage (p=0.352) were not associated with the expression of IL-17 in JNA patients. However, intratumoral IL-17-producing cells were negatively associated with patient's age (p=0.004). Furthermore, we found that patients with extensive infiltration of IL-17-producing cells had significantly higher recurrence rates than those with less infiltration of IL-17-producing cells (p=0.028). Log rank analysis showed that JNA patients with high levels of IL-17 had significantly shorter disease free survival (DFS) than those with low levels of IL-17 (p=0.004). Univariate Cox regression analysis suggested that IL-17 and patient's age were significantly associated with DFS. Multivariate analysis indicated that high infiltration with IL-17-producing cells was associated with poor DFS. Of all clinicopathological features, IL-17 level was an independent factor predicting the patient's prognosis.

CONCLUSION

In JNA patients, a high level of IL-17-producing cells was negatively associated with patient's age. Patients with extensive infiltration of IL-17-producing cells had significantly higher tumor recurrence rates. High infiltration of IL-17-producing cells in JNA microenvironment is an independent poor prognostic factor for shorter disease-free survival. Future studies further focusing on the role of IL-17 may provide more promising therapeutic methods for extensive JNA tumors.

Systems-level analysis of clinically different phenotypes of juvenile nasopharyngeal angiofibromas

OBJECTIVES/HYPOTHESIS

To explore the molecular genetic background of juvenile nasopharyngeal angiofibromas and to identify biological processes and putative factors determining the different growth patterns of these tumors.

STUDY DESIGN

By comparing copy number and gene expression level changes of two clinically different phenotypes of juvenile nasopharyngeal angiofibromas, we aimed to find processes essential in the growth and development of these tumors. Based on the results and prior knowledge of the proteins significance for growth, we studied the expression of tyrosine kinase SYK in 27 tumor samples.

METHODS

Comparative genomic hybridization and gene expression analyses were performed for the two tumor samples, and protein expression of SYK was studied in 27 samples by immunohistochemical staining.

RESULTS

Between low- and high-stage juvenile nasopharyngeal angiofibromas, 1,245 genes showed at least a two-fold change in expression. The corresponding proteins of these transcripts were enriched in different biological processes. Protein kinase SYK was expressed in all 27 samples, and its intensity significantly correlated with tumor stage.

CONCLUSIONS

Because the molecular genetic background of juvenile nasopharyngeal angiofibroma is unknown, our aim was to investigate genomic alterations that could associate to low- and high-stage tumors. We were able to identify gene expression changes that relate to particular biological processes, but assessing clinically relevant molecular profiles still requires further characterization. Due to the low incidence of juvenile angiofibroma, in the future a combination of molecular profiling data from several studies would be useful in understanding the molecular background of the disease.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Juvenile nasopharyngeal angiofibroma: no evidence for inheritance or association with familial adenomatous polyposis

Juvenile nasopharyngeal angiofibromas (JNAs) are rare tumors with prominent vascularity and locally destructive growth. The pathogenesis of JNA is largely unknown. A causal association between JNA and familial adenomatous polyposis has been suggested. Twenty-one patients diagnosed with juvenile angiofibroma filled out a detailed patient questionnaire. No patients reported any relatives with nasopharyngeal angiofibroma or familial adenomatous polyposis. No significant regional clustering suggestive for founder effect could be identified. We believe that if there were a strong genetic predisposition or association with familial adenomatous polyposis, it should have been seen in this patient sample.

Stem cell-related proteins C-KIT, C-MYC and BMI-1 in juvenile nasopharyngeal angiofibroma--do they have a role?

Juvenile nasopharyngeal angiofibroma (JNA) is a highly vascular tumour, occurring almost exclusively in adolescent males. Histogenesis of JNA remains unclear, two optional theories proposing either fibrous or vascular tissue as the tissue of origin. Stem cell-related proteins have been discussed to possibly participate in the growth of these tumours. In our study, we reviewed retrospective clinicopathological data of 26 JNA patients. By immunohistochemistry, we investigated the cellular distribution and expression levels of stem cell-related proteins C-KIT, C-MYC and BMI-1 and their correlation with cell and vessel density of the tumour. Contrary to earlier reports, we detected C-KIT expression in addition to stromal cells also in endothelial cells. The C-KIT expression was more dominant in slit vessels than large vessels. A significant correlation was found between endothelial immunoexpression of C-KIT and cellular density of the tumour. C-MYC and BMI-1 expression was detected in stromal cells only. Due to our finding of C-KIT expression in both stromal and endothelial cells and the strong correlation between the endothelial C-KIT expression and cellular density, we suggest that, besides the stromal tissue, the vascular component might take part in the neoplastic growth of JNA.

The changing surgical management of juvenile nasopharyngeal angiofibroma

The management of juvenile nasopharyngeal angiofibroma (JNA) has changed during the last decades but it still continues to be a challenge for the multidisciplinary head and neck surgical team. The aim of this study was to review the used treatment approach and outcome of JNA in a single institution series of 27 patients diagnosed and treated during the years 1970-2009. All patients were male, with the median age of 17 years (range 11-33 years). Surgery was used as the primary treatment in every case. Surgical approaches varied, transpalatal approach (N = 14) being the most common approach used in this series. During the last decade various other techniques were applied, including endoscopic (N = 3) resection. Two patients were additionally treated with antiangiogenic agents and one patient with stereotactic radiotherapy. The primary recurrence rate was 37% and it seemed to correlate with vascular density of tumour and the surgical approach used. We suggest that the management of JNA should be planned by an experienced head and neck surgeon, as part of a multidisciplinary team, preferably in a tertiary referral setting, and the recent development of the available therapies should be taken into account to minimise the risk of recurrence.

Markers of vascular differentiation, proliferation and tissue remodeling in juvenile nasopharyngeal angiofibromas

Juvenile nasopharingeal angiofibroma (JNA) is a histologically benign locally aggressive tumor characterized by irregular vessels embedded in a fibrous stroma. Excessive vascularity results in bleeding complications, and the inhibition of angiogenesis is a promising strategy for managing extensive JNA tumors. To better characterize the endothelial components of JNA, we aimed to evaluate markers of vascular differentiation and proliferation, such as friend leukemia integration-1 (FLI-1) and endoglin, lymphatic markers, including podoplanin and vascular endothelial growth factor receptor 3 (VEGFR3) and its cognate ligand VEGFC, GLUT-1, a diagnostic marker that discriminates between hemangiomas and vascular malformations, and two markers of tissue remodeling, stromelysin 3 (ST3) and secreted acid protein rich in cysteine (SPARC). Antigens were assessed immunohistochemically in vessels and stromal cells of JNA archival cases (n=22). JNA endothelial cells were positive for endoglin, VEGFC and FLI-1, whereas podoplanin and VEGFR3 were negative in all cases. Both endothelial cells and fibroblasts stained for ST3 and SPARC. GLUT-1 was investigated in JNA cases, in infantile hemangiomas (n=123) and in vascular malformations (n=135) as controls. JNAs and vascular malformations were GLUT-1-negative, while hemangiomas showed positive staining. The presence of markers of endothelial differentiation and proliferation highlighted the hyper-proliferative state of JNA vessels. The absence of podoplanin and VEGFR3 underscores their blood endothelial cell characteristic. The absence of GLUT-1 discriminates JNAs from hemangiomas. ST3 and SPARC up-regulation in endothelial cells and fibroblasts may contribute to a compensatory signaling for controlling angiogenesis. Some of these markers may eventually serve as therapeutic targets. Our results may aid in the understanding of JNA pathophysiology.

Imaging of head and neck neoplasms in children

The characteristic imaging appearance for a variety of common and/or important pediatric head and neck tumors will be described in this review. These include benign masses such as hemangioma, teratoma, nerve sheath tumors, juvenile nasopharyngeal angiofibroma and malignant masses such as rhabdomyosarcoma, lymphoma, carcinoma and retinoblastoma. This review focuses primarily on soft tissue tumors.