Nasopharyngeal angiofibroma in patients with familial adenomatous polyposis

Review of Pediatric Head and Neck Neoplasms that Raise the Possibility of a Cancer Predisposition Syndrome

Cancer predisposition syndromes (CPS) are generally heritable conditions that predispose individuals to develop cancer at a higher rate and younger age than their representative general population. They are a significant cause of cancer related morbidity and mortality in the pediatric population. Therefore, recognition of lesions that may be associated with a CPS and alerting the clinicians to its implications is a crucial task for a diagnostic pathologist. In this review we discuss benign pediatric head and neck lesions associated with CPS namely: odontogenic keratocyst, juvenile nasopharyngeal angiofibroma, ossifying fibroma of the jaw, paraganglioma, plexiform neurofibroma, plexiform schwannoma, mucosal neuroma, and nevus sebaceous syndrome; along with malignant tumors such as squamous cell carcinoma. Several head and neck melanocytic, endocrine, and central nervous system tumors can also be associated with CPS; they are beyond the scope of this article. Nasal chondromesenchymal hamartoma is discussed elsewhere in this issue.

Mandibular Intraosseous Angiofibroma-A Rare Clinical Entity

Angiofibromas located in the maxillofacial region are rare and almost exclusively occur in adolescent males. These benign tumors are highly vascular, locally invasive, and commonly found in the nasopharyngeal space. In the present report, we describe a very rare case of an intraosseous mandibular angiofibroma in a 23-year-old male patient with histomorphologic and molecular confirmation. This type of tumor occurring in the mandible has been reported previously only once, to the best of our knowledge.

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.

Familial Adenomatous Polyposis Syndrome: An Update and Review of Extraintestinal Manifestations

CONTEXT.—

Familial adenomatous polyposis (FAP) is a rare genetic disorder with autosomal dominant inheritance, defined by numerous adenomatous polyps, which inevitably progress to colorectal carcinoma unless detected and managed early. Greater than 70% of patients with this syndrome also develop extraintestinal manifestations, such as multiple osteomas, dental abnormalities, and a variety of other lesions located throughout the body. These manifestations have historically been subcategorized as Gardner syndrome, Turcot syndrome, or gastric adenocarcinoma and proximal polyposis of the stomach. Recent studies, however, correlate the severity of gastrointestinal disease and the prominence of extraintestinal findings to specific mutations within the adenomatous polyposis coli gene (APC), supporting a spectrum of disease as opposed to subcategorization. Advances in immunohistochemical and molecular techniques shed new light on the origin, classification, and progression risk of different entities associated with FAP.

OBJECTIVE.—

To provide a comprehensive clinicopathologic review of neoplastic and nonneoplastic entities associated with FAP syndrome, with emphasis on recent developments in immunohistochemical and molecular profiles of extraintestinal manifestations in the thyroid, skin, soft tissue, bone, central nervous system, liver, and pancreas, and the subsequent changes in classification schemes and risk stratification.

DATA SOURCES.—

This review will be based on peer-reviewed literature and the authors' experiences.

CONCLUSIONS.—

In this review we will provide an update on the clinicopathologic manifestations, immunohistochemical profiles, molecular features, and prognosis of entities seen in FAP, with a focus on routine recognition and appropriate workup of extraintestinal manifestations.

Gardener-associated fibroma: an unusual cause of upper airway obstruction

We present the first case of upper airway obstruction secondary to a retropharyngeal Gardner-associated fibroma (GAF). A 16-month-old infant presented with a 3-month history of worsening dyspnoea and apnoeic episodes. Examination revealed stridor and left-sided retropharyngeal asymmetry. MRI demonstrated a mass in the retropharynx. Tracheostomy and pharyngeal biopsy under anaesthesia were performed, and histology confirmed a diagnosis of GAF. The mass was excised using a transcervical approach, and postoperative recovery was unremarkable. GAF is associated with Gardner's syndrome (GS) and familial adenomatous polyposis (FAP), both of which are associated with multiple colonic polyps and increased risk of colorectal malignancy. Subsequent testing for an APC mutation seen in GS and FAP was negative in our patient. The details of this unusual presentation of a rare disease are given in addition to a review of the literature.

Reassessing the Anatomic Origin of the Juvenile Nasopharyngeal Angiofibroma

OBJECTIVE

A modern imaging review is necessary to further define the anatomic origin of the juvenile nasopharyngeal angiofibroma.

METHODS

After institutional review board approval, a search from January 1998 to January 2013 yielded 33 male patients (aged 10-23 years) with pathologically proven juvenile nasopharyngeal angiofibroma lesions, as well as pretreatment computed tomography/magnetic resonance imaging. Juvenile nasopharyngeal angiofibroma involvement was assessed in the following regions: sphenopalatine foramen, pterygopalatine fossa, vidian canal, nasopharynx, nasal cavity, sphenoid sinus, choana, pterygomaxillary fissure/masticator space, orbit, and sphenoid bone.

RESULTS

The choana and nasopharynx were involved in all 33 patients. In contrast, only 22 lesions involved the pterygopalatine fossa, 24 lesions involved the sphenopalatine foramen, and 28 lesions involved the vidian canal.

CONCLUSIONS

Our results suggest that the juvenile nasopharyngeal angiofibroma origin is in the region of the choana and nasopharynx rather than the sphenopalatine foramen or pterygopalatine fossa.

Distinctive Head and Neck Bone and Soft Tissue Neoplasms

Benign and malignant primary bone and soft tissue lesions of the head and neck are rare. The uncommon nature of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, radiographic, and pathologic features of selected bone and soft tissue tumors involving the head and neck region, including angiofibroma, glomangiopericytoma, rhabdomyosarcoma, biphenotypic sinonasal sarcoma, chordoma, chondrosarcoma, and osteosarcoma. Emphasis is placed on key diagnostic pitfalls, differential diagnosis, and the importance of correlating clinical and radiographic information, particularly for tumors involving bone.

Update From The 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Nasopharynx

The current WHO classification system for tumors of the head and neck has made few changes from the previous edition with regards to tumors of the nasopharynx. The classification system is discussed here with particular attention to nasopharyngeal carcinoma, nasopharyngeal papillary adenocarcinoma, salivary gland anlage tumor, hairy polyp, juvenile angiofibroma, and other tumors.

Current status and clinical association of beta-catenin with juvenile nasopharyngeal angiofibroma

OBJECTIVE

A possible role of the APC/beta-catenin pathway in the pathogenesis of sporadic juvenile nasopharyngeal angiofibroma has been suggested. This paper presents its current status and clinical association in our patients.

METHOD

A prospective observational study was conducted at King George Medical University and Central Drug Research Institute, in Lucknow, India. Western blot analysis was undertaken in 16 cases to examine beta-catenin expression. The clinical details were recorded along with follow up observations, to determine associations.

RESULTS

Up-regulation of beta-catenin expression was seen in 69 per cent of cases. The clinical variables did not reveal significant differences between patients with extremes of expression (extreme under- vs over-expression). However, absent expression was shown exclusively in young adults aged over 18 years, while enhanced expression was associated with an altered facial profile.

CONCLUSION

Although a beta-catenin association was seen in a subset of our sporadic juvenile nasopharyngeal angiofibroma cases, its expression was not homogeneous. This is in contrast to the Western literature that suggests a universal (homogenous) enhanced expression in the majority. Hence, further research is required to better define its molecular cascade.

Identification of CTNNB1 mutations, CTNNB1 amplifications, and an Axin2 splice variant in juvenile angiofibromas

Juvenile angiofibromas (JAs) are benign fibro-vascular tumors occurring nearly exclusively in adolescent males. Even less is known about this rare tumor entity, alterations affecting the Wnt-pathway seem to play a pivotal role in tumor biology as activating CTNNB1 mutations have been detected. However, the knowledge of Wnt-pathway changes is still limited. Therefore, we aimed to determine in JAs further insight into Wnt/β-catenin pathway components. In our present study, genetic alterations of the Wnt-pathway members CTNNB1, APC, GSK3β, and Axin2 detected by metaphase comparative genomic hybridization (CGH) were shown to result in elevated transcript levels in the majority of JA samples compared to nasal mucosa stroma (p < 0.001, p = 0.001, p = 0.046, and p = 0.006, respectively). Additionally, amplifications of CTNNB1 were validated by fluorescence in situ hybridization (FISH) and genomic qPCR. Moreover, our mutation analysis detected already known mutations as well as, to the best of our knowledge, mutations and an interstitial deletion of CTNNB1 not described in JAs before. Additionally, a so far unknown transcribed Axin2 splice variant was found, but no further Axin2 mutations. Taken together, our current study supports the importance of aberrant Wnt-signaling as a common event in JAs, most likely by the observed genetic alterations driven by mutations, interstitial deletions but also amplifications of CTNNB1 contributing to the stabilization of β-catenin.

The relevance of piroxicam for the prevention and treatment of nonmelanoma skin cancer and its precursors

Piroxicam (PXM), a nonsteroidal anti-inflammatory drug, is an enolic benzothiazine and a potent member of the oxicam series. The drug suppresses the synthesis of proinflammatory enzymes, such as cyclo-oxygenases-1 and -2 (COX-1 and 2), downregulates the production of prostaglandins (PGs) and tromboxanes, and inhibits polyamines production by blocking ornithine decarboxylase induction involved in nonmelanoma skin carcinogenesis. In addition, PXM is able to induce tumor cell apoptosis and suppresses metalloproteinase 2 activities. Skin carcinogenesis is a multistep process in which the accumulation of genetic events leads to a gradually dysplastic cellular expression, deregulation of cell growth, and carcinomatous progression. COX-1 upregulation plays a significant role in PG and vascular epidermal growth factor production supporting tumor growth. Increased level of PGs in premalignant and/or malignant cutaneous tumors is also favored by upregulation of COX-2 and downregulation of the tumor suppressor gene 15-hydroxy-prostaglandin dehydrogenase. Chemoprevention can be a hopeful approach to inhibit carcinoma occurrence before an invasive tumor develops. The chemopreventive effect of nonsteroidal anti-inflammatory drugs on nonmelanoma skin cancers has been established. In this study, we highlighted the different modalities of action of PXM on the pathogenesis of nonmelanoma skin cancer, analyzing and evaluating binding modes and energies between COX-1 or COX-2 and PXM by protein–ligand molecular docking. Our clinical experience about the local use of PXM on actinic keratoses and field cancerization is also reported, confirming its efficacy as target therapy.

Soft tissue tumors of the sinonasal tract

Primary soft tissue tumors arising in the sinonasal tract are rare. While many mesenchymal neoplasms have been reported in the nasal cavity, sinuses, and nasopharynx, few are distinctive to this anatomic region. Some tumor types are relatively more common in this area, such as schwannoma and rhabdomyosarcoma. Nasopharyngeal angiofibroma and sinonasal hemangiopericytoma are unique entities of the sinonasal tract, as well as the recently characterized biphenotypic sinonasal sarcoma. This review discusses the clinical, morphologic, and immunohistochemical features and currently known molecular data of the more frequently encountered soft tissue tumors of the sinonasal tract.

Hereditary Colorectal Cancer: Genetics and Screening

Colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer death in men and women in the United States. About 30% of patients with CRC report a family history of CRC. However, only 5% of CRCs arise in the setting of a well-established mendelian inherited disorder. In addition, serrated polyposis is a clinically defined syndrome with multiple serrated polyps in the colorectum and an increased CRC risk for which the genetics are unknown. This article focuses on genetic and clinical aspects of Lynch syndrome, familial adenomatous polyposis, and MUTYH-associated polyposis.

Diagnosis, surveillance, and treatment strategies for familial adenomatous polyposis: rationale and update

Familial adenomatous polyposis is characterized by the development of multiple (>100) colorectal adenomas throughout the colorectum. This disorder can be caused by a germline mutation in the adenomatous polyposis coli gene and can be diagnosed either clinically or genetically. After diagnosis with the condition, patients should undergo prophylactic proctocolectomy with a neoreservoir, usually an ileoanal pouch, at an appropriate time. Individuals with a family history of this disease who have not been diagnosed should be advised to attend genetic counseling and to enroll in appropriate clinical and genetic surveillance programs. Recent progress in endoscopic technology, including high-resolution endoscopy, capsule endoscopy, and double-balloon endoscopy, has made possible more detailed and wide-ranging investigation of the gastrointestinal tract. Although there has been limited evidence, further studies on these new endoscopic technologies might alter the surveillance strategies for familial adenomatous polyposis.

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.

Pediatric fibroblastic and myofibroblastic lesions

Fibrous lesions of infancy and childhood are a heterogeneous group of entities composed predominantly of fibroblasts and myofibroblasts, ranging from reactive lesions to neoplasms with a range of malignant potential. Although rare, their correct recognition by histopathology is important clinically as they exhibit a wide range of behaviors and may be associated with distinct underlying syndromes. Contributions from molecular diagnostics have enabled more accurate diagnosis, and have changed our concepts of some tumor types. In this review, we discuss the clinicopathologic spectrum of fibroblastic and myofibroblastic lesions of childhood and adolescence.

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.

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

Juvenile nasopharyngeal angiofibroma (JNA) is a rare, invasive, and locally destructive tumor of the nasopharynx. The Wnt pathway, angiogenetic and hormonal factors are involved in the pathophysiology of JNA; it can result in an extracolonic manifestation of familial adenomatous polyposis (FAP) or in a sporadic tumor. All patients who underwent resection of JNA between 1991 and 2006 at the University of Modena and Reggio Emilia were studied to identify immunohistochemical markers of associated FAP syndrome. Paraffin-embedded JNA samples were analyzed immunohistochemically for the expression of adenomatous polyposis coli (APC), beta-catenin, E-cadherin, androgen receptor, and vascular endothelial growth factors receptor (VEGFR2). In one out of the 4 (25%) young patients affected by JNA the diagnosis of FAP syndrome linked to APC mutation was made. All of the sporadic and familial JNA tumors showed nuclear staining of beta-catenin, whereas altered APC expression was seen only in FAP-associated JNA. All cases were stained with VEGFR2. A combined clinical, immunohistochemical, and biomolecular screening may be useful for the identification of FAP among patients with a diagnosis of JNA. The Wnt pathway can be involved in the JNA pathogenesis either by somatic mutations of beta-catenin or by germline APC mutations. As the VEGFR has an important impact on the pathogenesis of JNA, we suggest that a targeted therapy with monoclonal antibodies against VEGFR might lead to a specific chemoprevention and treatment of these tumors and their recurrences.

Extra-intestinal manifestations of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, which results from a germ line mutation in the APC (adenomatous polyposis coli) gene. FAP is characterized by the formation of hundreds to thousands of colorectal adenomatous polyps. Although the development of colorectal cancer stands out as the most prevalent complication, FAP is a multisystem disorder of growth. This means, it is comparable to other diseases such as the MEN syndromes, Von Hippel-Lindau disease and neurofibromatosis. However, the incidence of many of its clinical features is much lower. Therefore, a specialized multidisciplinary approach to optimize health care-common for other disorders-is not usually taken for FAP patients. Thus, clinicians that care for and counsel members of high-risk families should have familiarity with all the extra-intestinal manifestations of this syndrome. FAP-related complications, for which medical attention is essential, are not rare and their estimated lifetime risk presumably exceeds 30%. Affected individuals can develop thyroid and pancreatic cancer, hepatoblastomas, CNS tumors (especially medulloblastomas), and various benign tumors such as adrenal adenomas, osteomas, desmoid tumors and dental abnormalities. Due to improved longevity, as a result of better prevention of colorectal cancer, the risk of these clinical problems will further increase. We present a clinical overview of extra-intestinal manifestations, including management and treatment options for the FAP syndrome. Furthermore, we provide recommendations for surveillance of FAP complications based on available literature.

Genetic alterations in juvenile nasopharyngeal angiofibromas

Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign neoplasm of the nasopharynx that accounts for 0.5% of all head and neck tumors. Although histologically benign in appearance, JNAs are locally aggressive and destructive, spreading from the nasal cavity to the nasopharynx, paranasal sinuses, and orbit skull base with intracranial extension. The gender selectivity of JNA and the relatively young age at diagnosis suggest hormone-dependent development. Hormonal disorders have been reported in patients with JNA, and androgen and estrogen receptors have been identified in tumor tissue; however, a hormonal influence on JNA is controversial. Recent studies have attempted to further delineate the pathogenesis of JNA through analysis of genetic and molecular changes. Understanding of the molecular mechanisms involved in JNA might improve prevention, prognosis, and treatment of this tumor. In this review, we discuss published studies addressing the possible molecular pathways that might be involved in the development of JNA.

Genetic alteration in hereditary colorectal cancer

Colorectal cancer is a major cause of morbidity and mortality. Both genetic and environmental factors contribute to cancer aetiology. About 15-20% of all colorectal cancers are familial. Approximately 6% of colorectal cancers can be attributed to recognizable heritable germline mutations. The discovery of genes responsible for inherited forms of colorectal cancer have the potential to improve cancer risk assessment and counselling. Genetic testing for hereditary forms of colorectal cancer can confirm or reject diagnoses at the molecular level, determine surveillance intervals for at-risk persons, decrease the cost of surveillance by risk stratification, aid in surgical and chemoprevention decision-making, and help patients in family and career planning. This paper reviews the genetics behind genes and molecular study of the hereditary colorectal cancer. This may help the medical professionals especially internists, gastroenterologists, and oncologists to update their knowledge in this field.

New aspects of pathogenesis of juvenile angiofibroma

For over 150 years the aetiology of juvenile angiofibroma has been addressed in numerous theories, but actual details remained unknown. Interesting new findings, reviewed here, are beginning to elucidate the aetiology of this fascinating tumour.

Growth factors and receptors in juvenile nasopharyngeal angiofibroma and nasal polyps: an immunohistochemical study

BACKGROUND

Juvenile nasopharyngeal angiofibroma is a rare nasopharyngeal tumor that occurs exclusively in adolescent boys. It is a histologically benign but locally persistent growth of stromal and vascular tissue. Although male hormones and some growth factors, such as transforming growth factor beta1 (TGF-beta1), insulin-like growth factor II (IGF-II), and, lately, the proto-oncogene beta-catenin, have been implicated in the histogenesis of the tumor, the biologic signaling pathways that drive this peculiar fibrovascular proliferation are still nuclear.

OBJECTIVE

To evaluate immunoexpressions of beta-catenin, c-Kit, p130Cas, TGF-beta3, bone morphogenic protein 4, nerve growth factor (NGF), and the IGF receptor (IGF-1R) in a series of juvenile nasopharyngeal angiofibromas and to compare to that of a group of nasal polyps.

DESIGN

A standard immunohistochemical technique was used on paraffin sections of 12 sporadic juvenile nasopharyngeal angiofibromas and 15 nasal polyps with microwave or steam antigen retrieval. Immunoreactivity was analyzed semiquantitatively in stromal cells and endothelial cells of each case.

RESULTS

The expressions of beta-catenin (nuclear), c-Kit (cytoplasmic), and NGF (cytoplasmic) were higher and more frequent in stromal cells of juvenile nasopharyngeal angiofibromas than those of nasal polyps. Both juvenile nasopharyngeal angiofibromas and nasal polyps showed similarly frequent and strong immunoreactivity for p130Cas and TGF-beta3 and weak immunoreactivity for bone morphogenic protein 4 in both stromal cells and endothelial cells. No IGF-1R immunoreactivity was detected in any case of either group.

CONCLUSIONS

Our results support the role of beta-catenin in juvenile nasopharyngeal angiofibromas and suggest a potential involvement of c-Kit and NGF signaling pathways in the juvenile nasopharyngeal angiofibromas. Although the biologic significance of c-Kit in juvenile nasopharyngeal angiofibromas has yet to be defined, the finding of frequent and high c-Kit expression might have therapeutic importance for patients with juvenile nasopharyngeal angiofibromas.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

[Advances in the diagnosis of ENT tumors in childhood]

In the present study we review ENT tumor pathology in childhood. Only the most salient aspects are emphasized and the variety of entities reviewed was restricted. Molecular biology techniques reveal infection by human papilloma virus (types 6 and 11) in 50 % of papillomas, while immunohistochemical techniques are less effective in papilloma virus detection. The myofibroblastic nature of nasal angiofibroma has been demonstrated and its incidence is 25 times more frequent in patients with familial polyposis of the colon. Overexpression of p53 occurs in the initial stages of nasopharyngeal carcinoma, while overexpression of c-myc is correlated with an unfavorable prognosis. Recently, olfactory neuroblastoma has been shown not to express the protein product of the MIC-2 gene (antibody 12E7), thus the hypothesis that it could be a member of the Ewing tumor family (neuroectodermal peripheral tumors) has not been confirmed, although it is a primitive neural tumor. The head and neck rhabdomyosarcoma with the best prognosis is that located in the orbit, and cytogenetic studies have shown chromosomic translocation t(2;13) in 50 % of these childhood tumors when they are of the alveolar-type, while trisomy of chromosome 2 or 20 is more characteristic of the embryonic-type. Currently, any classifying features of ENT lymphomas must be based on the Revised European-American Classification of Lymphoid Neoplasms (REAL). Papillary and medullary carcinomas are the most common histological types of thyroid carcinoma in childhood. Alterations in ret/PTC play a significant role in the pathogenesis of both.

Review article: genetic testing and counselling for hereditary colorectal cancer

Colorectal cancer is the second leading cause of cancer death, after lung cancer, in the USA. The great majority (80%) of patients with colorectal cancer have sporadic disease with no evidence of having inherited the disorder. In the remaining 20%, a potentially definable genetic component exists. With the discovery of gene mutations related to hereditary colorectal cancer, risk assessment based on genetic test results is now feasible. The following review focuses on the two well-described colorectal cancer genetic syndromes-familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, the process of genetic counselling, currently available genetic tests, and indications for their use.

Diagnosis and management of hereditary colon cancer

Colorectal cancer is the third leading cause of cancer and the second leading cause of cancer death in the United States. About 130,000 new cases are diagnosed each year in North America, and 56,600 persons die annually from this disease. Approximately 5% of patients with colorectal cancer have clearly defined inherited syndromes such as familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. These conditions are well described both genetically and phenotypically, and are characterized by autosomal dominant inheritance, high penetrance, and high risk of colorectal cancer. We review the current recommendations for the diagnosis and management of these two hereditary forms of colorectal cancer.

First evidence of genetic imbalances in angiofibromas

OBJECTIVE/HYPOTHESIS

Angiofibromas are clinically well characterized by their origin at the posterior lateral nasal wall close to the sphenopalatine foramen, their occurrence in male adolescent patients, and the histological findings of a benign fibrovascular neoplasm with irregular, endothelium-lined vascular spaces in a fibrous stroma. However, their etiology and genetic causes remain unknown. The present study addresses genetic imbalances in angiofibromas.

STUDY DESIGN

The present pilot study compared genomic hybridization in three angiofibromas to search for chromosomal abnormalities in this rare tumor.

METHODS

Fluorescence-marked normal DNA and angiofibroma DNA were compared using genomic hybridization screening to detect chromosomal abnormalities. Their binding ratio to metaphase chromosomes were analyzed by special digital image analysis.

RESULTS

Chromosomal gains and losses showing a high level of agreement were detected in all three angiofibromas. Specifically, DNA gains were observed on chromosomes 3q, 4q, 5q, 6q, 7q, 8q, 12p, 12q, 13q, 14q, 18q, 21q, and X, and DNA losses were screened on chromosomes 17, 19p, 22q, and Y. Finding chromosomal abnormalities at the sex chromosomes X and Y of this rare tumor is remarkable. Concurrent chromosomal gain on 8q12q22 was noted in all three tumor specimens.

CONCLUSIONS

Comparative genomic hybridization is suitable for screening angiofibromas on a genetic level. The results on these screens indicate that further genetic investigations of this rare benign tumor may provide more details about the tumor's genetic abnormalities and perhaps clarify the etiology of angiofibromas.

Superficial fibromatoses are genetically distinct from deep fibromatoses

Whereas deep fibromatoses (abdominal, extra-abdominal, mesenteric) display locally aggressive behavior, superficial fibromatoses typically remain small and less likely to recur despite essentially identical morphology. Somatic beta-catenin or APC gene mutations have been reported in < or =74% of sporadic deep fibromatoses and in virtually 100% of Gardner syndrome-associated fibromatoses, whereas genetic events in superficial fibromatoses remain less well characterized. We performed immunohistochemical staining for beta-catenin on 29 superficial fibromatoses (22 palmar, 5 plantar, 1 penile, and 1 infantile digital fibromatosis) and 5 deep fibromatoses. Mutations of beta-catenin and APC genes were analyzed in cases of superficial fibromatoses by direct DNA sequencing of the beta-catenin gene on Exon 3 encompassing the GSK-3 36 phosphorylation region and of the APC gene on the mutation cluster region. Nuclear accumulation of beta-catenin was present in 86% (25/29) of superficial fibromatosis cases ranging from 5 to 100% of nuclei (mean, 13%; median, 10%), though in a minority of nuclei in most examples. Deep fibromatoses had 60 to 100% nuclear staining in all five cases. No somatic mutations of beta-catenin or APC genes were identified in any of the superficial fibromatoses. In contrast to deep fibromatoses, superficial fibromatoses lack beta-catenin and APC gene mutations; the significance of focal nuclear beta-catenin accumulation is unclear. This difference may account inpart for their divergent clinical manifestations despite their morphologic resemblance to deep fibromatoses.

Frequent beta-catenin mutations in juvenile nasopharyngeal angiofibromas

Juvenile nasopharyngeal angiofibromas (JNAs) are locally aggressive vascular tumors occurring predominantly in adolescent males. The pathogenesis of JNAs is unknown. Recently, JNAs have been reported to occur at increased frequency among patients with familial adenomatous polyposis, suggesting that alterations of the adenomatous polyposis coli (APC)/beta-catenin pathway might also be involved in the pathogenesis of sporadic JNAs. We analyzed somatic beta-catenin and APC gene mutations in 16 sporadic JNAs from nonfamilial adenomatous polyposis patients using immunohistochemistry for beta-catenin, and direct DNA sequencing for exon 3 of the beta-catenin gene and the mutation cluster region of the APC gene. Nuclear accumulation of beta-catenin was diffusely present in the stromal cells but not in the endothelial cells of all 16 JNAs. Activating beta-catenin gene mutations were present in 75% (12 of 16) of JNAs. Six JNA patients also had recurrent tumors after surgery, and in all cases the beta-catenin gene status of the recurrent JNA was identical to the initial tumor. No mutations in the mutation cluster region of the APC gene were detected in the four JNAs without beta-catenin mutations. The high frequency of beta-catenin mutations in sporadic JNAs and the presence of identical beta-catenin gene mutations in recurrent tumors indicates that activating beta-catenin gene mutations are important in the pathogenesis of JNAs. The immunohistochemical localization of beta-catenin only to the nuclei of stromal cells further suggests that the stromal cells, rather than endothelial cells, are the neoplastic cells of JNAs.

Genetic alterations in Ki-ras and Ha-ras genes in juvenile nasopharyngeal angiofibromas and head and neck cancer

CONTEXT

Ras gene mutations have been associated to a wide range of human solid tumors. Members of the ras gene family (Ki-ras, Ha-ras and N-ras) are structurally related and code for a protein (p21) known to play an important role in the regulation of normal signal transduction and cell growth. The frequency of ras mutations is different from one type of tumor to another, suggesting that point mutations might be carcinogen-specific.

OBJECTIVES

To study the occurrence of Ki-ras and Ha-ras mutations. We also studied the relative level of Ha-ras mRNA in 32 of the head and neck tumors.

DESIGN

Case series.

SETTING

University referral unit.

PARTICIPANTS

60 head and neck tumors and in 28 Juvenile Nasopharyngeal Angiofibromas (JNA).

DIAGNOSTIC TEST

Using PCR-SSCP we examined the occurrence of Ki-ras and Ha-ras mutations. The relative level of Ha-ras mRNA was examined by Northern blot analysis.

RESULTS

None of the head and neck tumors or JNA samples showed evidence of mutations within codons 12, 13, 59 and 61 of Ki-ras or Ha-ras genes. However, 17 (53%) of the tumors where gene expression could be examined exhibited increased levels of Ha-ras mRNA compared with the normal tissue derived from the same patient.

CONCLUSIONS

Our results demonstrate for the first time that mutations of Ki-ras and Ha-ras genes are not associated with the development of JNA and confirm previous reports indicating that activating ras mutations are absent or rarely involved in head and neck tumors from western world patients. Furthermore, our findings suggest that overexpression of Ha-ras, rather than mutations, might be an important factor in the development and progression of head and neck tumors.

Juvenile Nasopharyngeal Angiofibroma and Familial Adenomatous Polyposis: An Association?

Juvenile nasopharyngeal angiofibroma is a benign neoplasm affecting the nasopharynx of male adolescents. Two patients treated at Temple University Hospital for this condition were also diagnosed with familial adenomatous polyposis. Familial adenomatous polyposis results from the inheritance of a mutated adenomatous polyposis coli gene in an autosomal dominant pattern. The development of colorectal carcinoma in middle age is seen almost invariably in familial adenomatous polyposis, if a prophylactic colectomy is not performed. To identify a possible association between juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis, chart reviews and patient interviews were carried out for all patients treated for juvenile nasopharyngeal angiofibroma at Temple University Hospital between 1985 and 1993. Single-strand conformational polymorphism was performed to detect the presence of certain adenomatous polyposis coli gene mutations within the germline DNA of those juvenile nasopharyngeal angiofibroma patients not previously found to have familial adenomatous polyposis. Although no more patients with both juvenile nasopharyngeal angiofibroma and familial adenomatous polyposis were found by these methods, the two patients with both disorders previously identified constitute 22% of our juvenile nasopharyngeal angiofibroma series. The implications of these findings are discussed.

Phenotype and cancer risk of various polyposis syndromes

The gastrointestinal polyposis syndromes are disorders with multiple intestinal polyps. Three of these disorders, familial adenomatous polyposis, Peutz-Jeghers syndrome and juvenile polyposis are associated with increased risk of colorectal as well as extracolonic cancers. A description of the phenotype and associated cancer risk is provided for each.

The molecular basis of Turcot's syndrome

BACKGROUND

Turcot's syndrome is characterized clinically by the concurrence of a primary brain tumor and multiple colorectal adenomas. We attempted to define the syndrome at the molecular level.

METHODS

Fourteen families with Turcot's syndrome identified in two registries and the family originally described by Turcot and colleagues were studied. Germ-line mutations in the adenomatous polyposis coli (APC) gene characteristic of familial adenomatous polyposis were evaluated, as well as DNA replication errors and germline mutations in nucleotide mismatch-repair genes characteristic of hereditary nonpolyposis colorectal cancer. In addition, a formal risk analysis for brain tumors in familial adenomatous polyposis was performed with a registry data base.

RESULTS

Genetic abnormalities were identified in 13 of the 14 registry families. Germ-line APC mutations were detected in 10. The predominant brain tumor in these 10 families was medulloblastoma (11 of 14 patients, or 79 percent), and the relative risk of cerebellar medulloblastoma in patients with familial adenomatous polyposis was 92 times that in the general population (95 percent confidence interval, 29 to 269; P < 0.001). In contrast, the type of brain tumor in the other four families was glioblastoma multiforme. The glioblastomas and colorectal tumors in three of these families and in the original family studied by Turcot had replication errors characteristic of hereditary nonpolyposis colorectal cancer. In addition, germ-line mutations in the mismatch-repair genes hMLH1 or hPMS2 were found in two families.

CONCLUSIONS

The association between brain tumors and multiple colorectal adenomas can result from two distinct types of germ-line defects: mutation of the APC gene or mutation of a mismatch-repair gene. Molecular diagnosis may contribute to the appropriate care of affected patients.