RESUMEN
A 19-year-old man presented with a long-standing history of nasal obstruction, which gradually became worse over the past 2 years. Nasal endoscopy revealed a sizeable rounded mass covered by a normal-looking mucosa. Imaging studies showed a mass arising from the left middle turbinate that extended throughout the expanse of the anterior skull base. The tumour was resected via an endoscopic endonasal approach. Histopathological examination revealed a psammomatoid juvenile ossifying fibroma. The patient remains free of recurrence after almost 3 years of follow-up. Only four cases of ossifying fibroma with middle turbinate localisation have been reported in the literature so far, with our case representing the fifth and most extensive case. Clinical, radiological and histological findings should all be considered for establishing the correct diagnosis. An endoscopic approach represents an excellent therapeutic option. Long-term clinical and radiological surveillance is required due to the risk of recurrence.
Asunto(s)
Fibroma Osificante/diagnóstico , Fibroma Osificante/cirugía , Obstrucción Nasal/etiología , Neoplasias Nasales/diagnóstico , Neoplasias Nasales/cirugía , Endoscopía , Fibroma Osificante/clasificación , Humanos , Masculino , Neoplasias Nasales/clasificación , Resultado del Tratamiento , Cornetes Nasales/patología , Adulto JovenRESUMEN
Nasal chondromesenchymal hamartoma (NCMH), a rare, benign, nasal cavity tumor, typically occurs in children. Differential diagnosis is difficult because NCMH often presents with non-specific findings, including cystic components and invasion of the surrounding area on T2-weighted magnetic resonance images. Here, we present a rare adult case of NCMH, with no clear hyperintensity on diffusion-weighted images (DWI), and bone remodeling on the tumor margins on computed tomography. To the best of our knowledge, this is the first report of DWI on NCMH, and these findings, which suggest benign disease, may be useful in diagnosing NCMH.
Asunto(s)
Hamartoma/clasificación , Hamartoma/diagnóstico por imagen , Neoplasias Nasales/clasificación , Neoplasias Nasales/diagnóstico por imagen , Hamartoma/patología , Hamartoma/cirugía , Humanos , Masculino , Neoplasias Nasales/cirugía , Adulto JovenRESUMEN
Esthesioneuroblastoma (ENB) is a rare cancer of the olfactory mucosa, with no established molecular stratification to date. We report similarities of ENB with tumors arising in the neural crest and perform integrative analysis of these tumors. We propose a molecular-based subtype classification of ENB as basal or neural, both of which have distinct pathological, transcriptomic, proteomic, and immune features. Among the basal subtype, we uncovered an IDH2 R172 mutant-enriched subgroup (â¼35%) harboring a CpG island methylator phenotype reminiscent of IDH2 mutant gliomas. Compared with the basal ENB methylome, the neural ENB methylome shows genome-wide reprogramming with loss of DNA methylation at the enhancers of axonal guidance genes. Our study reveals insights into the molecular pathogenesis of ENB and provides classification information of potential therapeutic relevance.
Asunto(s)
Biomarcadores de Tumor/análisis , Linaje de la Célula/genética , Metilación de ADN , Estesioneuroblastoma Olfatorio/genética , Variación Genética , Cavidad Nasal/metabolismo , Neoplasias Nasales/genética , Biología Computacional , Islas de CpG , Epigénesis Genética , Estesioneuroblastoma Olfatorio/clasificación , Estesioneuroblastoma Olfatorio/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Linfocitos Infiltrantes de Tumor , Masculino , Persona de Mediana Edad , Cavidad Nasal/patología , Neoplasias Nasales/clasificación , Neoplasias Nasales/metabolismo , Pronóstico , Proteoma/análisis , Tasa de Supervivencia , TranscriptomaRESUMEN
The recently published 4th Edition of the World Health Organization Classification of Head and Neck Tumors addresses the most relevant and updated aspects of tumor biology, including clinical presentation, histopathology, immunohistochemistry, and prognosis of head and neck tumors. The objective of the present study is to compare these updates to the 3rd edition of that book with regard to mucosal melanomas and to highlight the potential factors that differ those tumors from cutaneous melanomas. We observed progress in the understanding of oral and sinonasal mucosal melanomas, which also present themselves, in the molecular scope, differently form cutaneous melanomas.
Asunto(s)
Neoplasias de Cabeza y Cuello/clasificación , Neoplasias Laríngeas/clasificación , Melanoma/clasificación , Neoplasias de la Boca/clasificación , Neoplasias Nasales/clasificación , Organización Mundial de la Salud , Humanos , Neoplasias Laríngeas/patología , Melanoma/patología , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Mucosa Nasal/patología , Neoplasias Nasales/patología , Neoplasias Cutáneas/clasificación , Neoplasias Cutáneas/patologíaRESUMEN
The publication of the new WHO classification of head and neck tumours in 2017 brought major modifications. Especially, a new chapter is dedicated to the oropharynx, focusing on the description of squamous cell carcinoma induced by the virus Human Papilloma Virus (HPV), and new entities of tumors are described in nasal cavities and sinuses. In this article are presented the novelties and main changes of this new classification, as well as the updates of the diagnostic methods (immunohistochemistry, cytogenetics or molecular biology).
Asunto(s)
Carcinoma de Células Escamosas/clasificación , Neoplasias de Cabeza y Cuello/clasificación , Papillomaviridae , Organización Mundial de la Salud , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/secundario , Carcinoma de Células Escamosas/virología , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/virología , Humanos , Metástasis Linfática , Neoplasias Nasofaríngeas/clasificación , Neoplasias Nasofaríngeas/virología , Neoplasias Nasales/clasificación , Neoplasias Nasales/diagnóstico , Neoplasias Orofaríngeas/clasificación , Neoplasias Orofaríngeas/diagnóstico , Neoplasias Orofaríngeas/virología , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de los Senos Paranasales/diagnósticoRESUMEN
Abstract: The recently published 4th Edition of the World Health Organization Classification of Head and Neck Tumors addresses the most relevant and updated aspects of tumor biology, including clinical presentation, histopathology, immunohistochemistry, and prognosis of head and neck tumors. The objective of the present study is to compare these updates to the 3rd edition of that book with regard to mucosal melanomas and to highlight the potential factors that differ those tumors from cutaneous melanomas. We observed progress in the understanding of oral and sinonasal mucosal melanomas, which also present themselves, in the molecular scope, differently form cutaneous melanomas.
Asunto(s)
Humanos , Organización Mundial de la Salud , Neoplasias de la Boca/clasificación , Neoplasias Laríngeas/clasificación , Neoplasias Nasales/clasificación , Neoplasias de Cabeza y Cuello/clasificación , Melanoma/clasificación , Neoplasias Cutáneas/clasificación , Neoplasias Cutáneas/patología , Neoplasias de la Boca/patología , Neoplasias Laríngeas/patología , Neoplasias Nasales/patología , Melanoma/patología , Mucosa Bucal/patología , Mucosa Nasal/patologíaRESUMEN
The sinonasal tract remains an epicenter of a diverse array of neoplasia. This paper discusses changes to the WHO classification system of tumors involving this area. In particular, seromucinous hamartoma, NUT carcinoma, biphenotypic sinonasal sarcoma, HPV-related carcinoma with adenoid cystic features, SMARCB1-deficient carcinoma, and renal cell-like adenocarcinoma are discussed.
Asunto(s)
Neoplasias Nasales/clasificación , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de la Base del Cráneo/clasificación , Humanos , Cavidad Nasal/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Neoplasias de la Base del Cráneo/patología , Organización Mundial de la SaludRESUMEN
A wide variety of tumors present in the sinonasal and ventral skull base. Patients often have nonspecific symptoms initially and present with advanced tumors, affecting the orbit and other adjacent structures. Evaluation of these malignancies with modern imaging techniques can define tumor invasion, but biopsy is often required to establish a diagnosis because most have a nonspecific appearance. A thorough understanding of the anatomy is the key to treatment planning, and a multidisciplinary approach determines the optimal strategy.
Asunto(s)
Neoplasias Nasales/diagnóstico por imagen , Neoplasias Nasales/patología , Neoplasias de la Base del Cráneo/diagnóstico por imagen , Neoplasias de la Base del Cráneo/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Clasificación del Tumor , Estadificación de Neoplasias , Neoplasias Nasales/clasificación , Órbita/patología , Base del Cráneo/patología , Neoplasias de la Base del Cráneo/clasificación , Tomografía Computarizada por Rayos X , Resultado del TratamientoAsunto(s)
Cavidad Nasal/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Biomarcadores de Tumor/análisis , Humanos , Cavidad Nasal/química , Cavidad Nasal/virología , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias Nasales/virología , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virología , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de los Senos Paranasales/virología , Pronóstico , Factores de RiesgoRESUMEN
Surgical pathology of the sinonasal region (i.e., nasal cavity and the paranasal sinuses) is notoriously difficult, due in part to the remarkable diversity of neoplasms that may be encountered in this area. In addition, a number of neoplasms have been only recently described in the sinonasal tract, further compounding the difficulty for pathologists who are not yet familiar with them. This manuscript will review the clinicopathologic features of some of the recently described sinonasal tumor types: NUT midline carcinoma, HPV-related carcinoma with adenoid cystic-like features, SMARCB1 (INI-1) deficient sinonasal carcinoma, biphenotypic sinonasal sarcoma, and adamantinoma-like Ewing family tumor.
Asunto(s)
Cavidad Nasal/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Biomarcadores de Tumor/análisis , Biopsia , Humanos , Inmunohistoquímica , Cavidad Nasal/química , Cavidad Nasal/virología , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias Nasales/virología , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virología , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de los Senos Paranasales/virología , Pronóstico , Factores de RiesgoRESUMEN
The differential diagnosis for small round cell tumors in the sinonasal tract is diverse and as the body of literature documenting not only uncommon presentations but also availability of ancillary studies grows, so does the need for a reminder to take a conservative and thorough approach before rendering a diagnosis. Small tissue samples are particularly problematic, with limitations that include volume of tumor cells available for studies, lack of architectural context and a non-specific gross description. Incorporation of patient history and presentation, radiologic findings, clinical impression and concurrent studies often guide the course of studies performed by the pathologist. If these are non-specific, the pathologist may need to perform ancillary studies, including a broad panel of immunohistochemical stains and molecular studies. If tissue is limited, a precise classification may not be achievable. Although the expectation to render a definitive diagnosis is high, the pathologist should never feel compelled to go further with a diagnosis than the tissue itself supports.
Asunto(s)
Cavidad Nasal/patología , Nevo Azul/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Neoplasias Cutáneas/patología , Biopsia , Diagnóstico Diferencial , Humanos , Inmunohistoquímica , Cavidad Nasal/química , Nevo Azul/química , Nevo Azul/clasificación , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , Valor Predictivo de las Pruebas , Pronóstico , Neoplasias Cutáneas/química , Neoplasias Cutáneas/clasificaciónRESUMEN
Various hematolymphoid lesions involve the sinonasal tract, including aggressive B, T, and NK-cell neoplasms; myeloid sarcoma; low-grade lymphomas; indolent T-lymphoblastic proliferations; and Rosai-Dorfman disease. Differentiating aggressive lymphomas from non-hematopoietic neoplasms such as poorly differentiated squamous cell carcinoma, olfactory neuroblastoma, or sinonasal undifferentiated carcinoma may pose diagnostic challenges. In addition, the necrosis, vascular damage, and inflammatory infiltrates that are associated with some hematolymphoid disorders can result in misdiagnosis as infectious, autoimmune, or inflammatory conditions. Here, we review hematolymphoid disorders involving the sinonasal tract including their key clinical and histopathologic features.
Asunto(s)
Histiocitosis Sinusal/patología , Leucemia-Linfoma de Células T del Adulto/patología , Linfoma/patología , Cavidad Nasal/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Biomarcadores de Tumor/análisis , Biopsia , Histiocitosis Sinusal/clasificación , Histiocitosis Sinusal/metabolismo , Humanos , Inmunohistoquímica , Leucemia-Linfoma de Células T del Adulto/clasificación , Leucemia-Linfoma de Células T del Adulto/metabolismo , Linfoma/química , Linfoma/clasificación , Cavidad Nasal/química , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , PronósticoRESUMEN
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.
Asunto(s)
Cavidad Nasal/patología , Neoplasias de los Tejidos Conjuntivo y Blando/patología , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patología , Biomarcadores de Tumor/análisis , Biopsia , Humanos , Inmunohistoquímica , Cavidad Nasal/química , Neoplasias de los Tejidos Conjuntivo y Blando/química , Neoplasias de los Tejidos Conjuntivo y Blando/clasificación , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , PronósticoRESUMEN
It is now well established that human papillomavirus (HPV) is an important causative factor in a subgroup of head and neck cancer. In the head and neck, while HPV is strongly associated with squamous cell carcinoma arising in the oropharynx, there is a growing interest in HPV-associated neoplasms of non-oropharyngeal origin including those which arise within sinonasal and nasopharyngeal mucosa. This article reviews current literature on the association of HPV with Scheiderian papillomas, sinonasal squamous cell carcinoma, sinonasal undifferentiated carcinoma, carcinoma with adenoid cystic-like features, and nasopharyngeal carcinoma. Several clinical implications of HPV detection in sinonasal and nasopharyngeal carcinomas are briefly discussed.
Asunto(s)
Cavidad Nasal/virología , Neoplasias Nasales/virología , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/virología , Neoplasias de los Senos Paranasales/virología , Biomarcadores de Tumor/análisis , Biopsia , ADN Viral/genética , Pruebas de ADN del Papillomavirus Humano , Humanos , Inmunohistoquímica , Cavidad Nasal/química , Cavidad Nasal/patología , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias Nasales/patología , Papillomaviridae/genética , Infecciones por Papillomavirus/patología , Neoplasias de los Senos Paranasales/química , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de los Senos Paranasales/patología , Valor Predictivo de las Pruebas , Factores de RiesgoRESUMEN
CONTEXT: The differential diagnosis of neuroendocrine neoplasms arising in the sinonasal tract is broad and includes lesions of epithelial, mesenchymal, and neuroectodermal origin. OBJECTIVE: To review the differential diagnosis of sinonasal neuroendocrine and neuroectodermally derived tumors. DATA SOURCES: The current literature was reviewed to provide updated information regarding the differential diagnosis and means for diagnosing neuroendocrine tumors including sinonasal neuroendocrine carcinoma, olfactory neuroblastoma, malignant melanoma, paraganglioma, pituitary adenoma, and Ewing family of tumors. CONCLUSIONS: The differential diagnosis of neoplasms with neuroendocrine differentiation in the sinonasal tract is broad, and diagnosis often includes not only histologic review but also immunohistochemical or molecular analysis.
Asunto(s)
Adenoma/diagnóstico , Tumores Neuroendocrinos/diagnóstico , Neoplasias Nasales/diagnóstico , Neoplasias Hipofisarias/diagnóstico , Adenoma/clasificación , Diagnóstico Diferencial , Estesioneuroblastoma Olfatorio/clasificación , Estesioneuroblastoma Olfatorio/diagnóstico , Humanos , Melanoma/clasificación , Melanoma/diagnóstico , Cavidad Nasal , Tumores Neuroendocrinos/clasificación , Neoplasias Nasales/clasificación , Paraganglioma/clasificación , Paraganglioma/diagnóstico , Neoplasias de los Senos Paranasales/clasificación , Neoplasias de los Senos Paranasales/diagnóstico , Neoplasias Hipofisarias/clasificaciónAsunto(s)
Biomarcadores de Tumor/metabolismo , Hemangiosarcoma/patología , Neoplasias Nasales/patología , Femenino , Hemangiosarcoma/clasificación , Hemangiosarcoma/cirugía , Humanos , Persona de Mediana Edad , Cavidad Nasal/patología , Neoplasias Nasales/clasificación , Neoplasias Nasales/cirugía , Senos Paranasales/patologíaRESUMEN
Capillary hemangiomas, the most common vascular tumors of the sinonasal region, are benign endothelial neoplasms, typically growing in an easily recognized lobular pattern. Some sinonasal capillary hemangiomas may show atypical features, such as high cellularity or mitotic activity, and represent more challenging diagnoses. Over the past several years we have seen in consultation a number of examples of sinonasal capillary hemangiomas displaying very striking stromal myxoid change and hyalinization, features that have received scant attention in the past. Available slides from 16 sinonasal capillary hemangiomas previously coded as showing such changes were retrieved from our archives. Submitting diagnoses included "query angiofibroma, rule out malignancy" (N=4), "vascular polyp, rule out malignancy" (N=3), "query malignant vascular tumor" (N=4), "sinonasal hemangiopericytoma" (N=1), and "benign vascular tumor" (N=1). Available radiographic studies often showed worrisome features. Grossly, the tumors ranged from 1.1 to 6.0 cm and appeared as ulcerated, vascular-appearing polyps. Microscopically, the tumors showed striking stromal myxoid change and/or hyalinization, which largely obscured the underlying lobular capillary arrangement. Within this myxohyaline matrix, a florid capillary proliferation was present, frequently with nonatypical mitotic activity. In some instances a branching, "hemangiopericytoma-like" vascular pattern was present in areas. The overall cellularity was low to moderate, and endothelial atypia or hyperchromatism was absent. Ulceration and thrombosis were frequently present. Immunostains to CD31, CD34, and SMA highlighted areas of lobular growth pattern inapparent on the routinely stained slides. Four tested cases were negative for androgen receptors and ß-catenin. Follow-up from 12 patients revealed no local recurrences or metastases. Awareness of that sinonasal capillary hemangioma may show these unusual stromal changes, and the use of ancillary immunohistochemistry to highlight its lobular growth pattern should allow its confident distinction from more aggressive endothelial tumors (eg, angiosarcoma) and from nonendothelial tumors, including nasopharyngeal angiofibroma, solitary fibrous tumor, and sinonasal hemangiopericytoma-like tumor.
Asunto(s)
Biomarcadores de Tumor/análisis , Hemangioma Capilar/patología , Hialina , Cavidad Nasal/patología , Mucosa Nasal/patología , Neoplasias Nasales/patología , Células del Estroma/patología , Adolescente , Adulto , Anciano , Biopsia , Niño , Diagnóstico Diferencial , Femenino , Hemangioma Capilar/química , Hemangioma Capilar/clasificación , Hemangioma Capilar/cirugía , Humanos , Inmunohistoquímica , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Cavidad Nasal/química , Cavidad Nasal/cirugía , Mucosa Nasal/química , Mucosa Nasal/cirugía , Neovascularización Patológica , Neoplasias Nasales/química , Neoplasias Nasales/clasificación , Neoplasias Nasales/cirugía , Valor Predictivo de las Pruebas , Células del Estroma/química , Tomografía Computarizada por Rayos X , Carga TumoralRESUMEN
While sinonasal intestinal type adenocarcinoma (ITAC) is defined by an intestinal phenotype, non-intestinal type adenocarcinoma (non-ITAC) is traditionally viewed as a diagnosis of exclusion, despite previous implication of a seromucinous phenotype and similarity to sinonasal seromucinous hamartomas (SSH). We performed a comparison of clinicopathologic and immunophenotypic features of ITAC, non-ITAC and SSH using traditional discriminatory markers and new markers of seromucinous differentiation. Twenty-three non-ITAC, 17 ITAC, and 5 SSH were retrieved (1987-2014). As expected, ITAC occurred predominantly in the nasal cavity in elderly patients (mean age 65 years) with a striking male predilection (15:2). Regardless of grade/subtype, all ITAC were invariably CK20 and CDX2 positive, and many (11/15) showed some CK7 positivity. Non-ITAC occurred in younger individuals (mean age 51 years) with a slight female predilection (male to female ratio: 10:13) and showed diverse morphologic patterns and grades, some with morphologic similarity to SSH. SSH occurred in younger individuals (mean age 33 years). Non-ITAC and SSH were invariably CK7 positive and CK20 negative, however, 4/22 non-ITAC and 2/5 SSH showed squamoid morular metaplasia that aberrantly expressed CDX2 and co-expressed nuclear ß-catenin. Markers of seromucinous differentiation (S100, DOG1, and SOX10) were essentially absent in ITAC, but present to varying degrees in the majority of non-ITAC and all SSH. Thus, the term 'seromucinous adenocarcinoma' is the more appropriate designation for non-ITAC. Squamoid morules in non-ITAC and SSH may be an immunophenotypic pitfall given the aberrant CDX2 expression.
Asunto(s)
Adenocarcinoma/clasificación , Biomarcadores de Tumor/análisis , Neoplasias Nasales/clasificación , Neoplasias de los Senos Paranasales/clasificación , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Inmunohistoquímica , Inmunofenotipificación , Masculino , Persona de Mediana Edad , Neoplasias Nasales/patología , Neoplasias de los Senos Paranasales/patologíaRESUMEN
Esthesioneuroblastoma is a sinonasal tumor with distinct clinicopathologic features, multiple facets, and a spectrum of behavior. Characterization of this disease is challenging, and clinically, several staging systems have been used with no consensus on a single scheme. Recently, the Hyams histological grading system has emerged as a promising prognostication tool that offers an added value to stage. This review addresses prognosis and biology in esthesioneuroblastoma. More specifically, we sought to present a critical appraisal on the value of each of these stratification systems, stage vs. grade, in identifying risk groups and guiding management.
Asunto(s)
Estesioneuroblastoma Olfatorio/patología , Estadificación de Neoplasias/métodos , Neoplasias Nasales/patología , Estesioneuroblastoma Olfatorio/clasificación , Humanos , Neoplasias Nasales/clasificación , Pronóstico , Estudios RetrospectivosRESUMEN
OBJECTIVES: Nasal dermoids are rare developmental anomalies seen in children. This study reports the largest case series of 103 patients seen in a quaternary specialist unit over a 10-year period. We report the surgical and radiological findings and propose a new classification system, which clearly describes the extent of the lesions, thus allowing better surgical planning. METHODS: A retrospective review of case notes was conducted. Data collection included demographics, initial presentation, site of lesion, pre-operative CT and MRI imaging, surgical procedure, intraoperative findings (including depth of lesion), complications and recurrence. Surgical findings were correlated with radiological findings. RESULTS: A total of 103 patients were included in the study. The mean age at presentation was 29 months. 89% of children presented with a naso-glabellar or columellar lesion and 11% had a medial canthal lesion. All the patients underwent preoperative imaging and were treated with surgical excision. 58 children had superficial lesions, 45 had subcutaneous tracts extending to varying depths. Of these, 38 had intraosseous extension into the frontonasal bones, eight extended intracranially but remained extradural and two had intradural extension. There was good correlation between radiological and surgical findings. The superficial lesions were locally excised. The lesions with intraosseous tracts were removed via open rhinoplasty and the frontonasal bones drilled for access. Intracranial extension was approached either via a bicoronal flap and frontal craniotomy or the less invasive anterior small window craniotomy. CONCLUSIONS: This report describes the largest published cases series of nasal dermoids. The cases demonstrate the presenting features and the variable extent of the lesions. The new proposed classification; superficial, intraosseous, intracranial extradural and intracranial intradural, allows precise surgical planning. In the presence of intracranial extension, the low morbidity technique of using a brow incision and small window anterior craniotomy avoids the more invasive and commonly used bicoronal flap and frontal craniotomy.