Clinical and radiological profile of ameloblastic fibro-odontoma: an update on an uncommon odontogenic tumor based on a critical analysis of 114 cases

Solitary ameloblastic fibroma with impacted teeth: A case report

This case report aimed to describe a rare benign mandibular tumour and assess the outcomes of the most recent reviews, between January 2017 and August 2023. Presenting a detailed clinical case, this study advances our understanding of the diagnostic and therapeutic aspects, ultimately improving the management of similar cases in clinical practice. Orthopantomogram (OPG) revealed a well-defined unilocular radiolucency extending from the midline of the ramus and teeth 47 and 48 were submerged at the base of the mandible. In the presented case, a PLANMECA ROMEXIS PROMAX® three-dimensional (3D) maximum (MAX) cone-beam computed tomography (CBCT) device was used for the 3D examination. An intraoral approach was preferred and the tumour was removed in toto by creating a bone window using a W&H® Dentalwerk Bürmoos GmbH Piezomed piezoelectric device, and the bone plates were fixed with 4 MEDARTIS® microplates, with a primary flap closure. A PANORAMIC 1000, 3DHISTECH Ltd® device was employed for the histological investigation. Odontogenic tumours are rare and typically asymptomatic, often discovered incidentally during routine radiographic examinations. Most of these benign lesions heal well after complete excision and require long-term follow-up. Once diagnosed, ameloblastic fibroma (AF) should be treated immediately to avoid malignant transformation.

Aggressive presentation of ameloblastic fibro-odontoma: a clinical-pathological enigma

Ameloblastic fibro-odontoma (AFO) is a rare, gnathic, benign, mixed odontogenic tumor that commonly presents in the first or second decade of life as a unilocular and rarely multilocular radiolucency with variable amounts of calcified material. Tumor progression is typically indolent, and generally accepted treatment is surgical enucleation and curettage. This case report describes an atypical presentation in a 14-year-old male with a multilocular, aggressive AFO requiring hemimandibulectomy with immediate osseous and dental "Jaw-in-a-Day" reconstruction. This report highlights the debate regarding whether AFO is a true neoplasm or an early-stage hamartoma in the continuum of complex odontoma formation. Regardless of the pathogenesis, maxillofacial surgeons and pathologists should be cognizant of the potential for AFO to develop locally aggressive behavior with considerable morbidity.

Reticular Myxoid Odontogenic Neoplasm with Novel STRN::ALK Fusion: Report of 2 Cases in 3-Year-Old Males

Odontogenic tumors represent a collection of entities ranging from hamartomas to destructive benign and malignant neoplasms. Occasionally, pathologists encounter gnathic lesions which clearly exhibit an odontogenic origin but do not fit within the confines of established diagnoses. Here, we describe two such odontogenic tumors, both affecting 3-year-old males. Each case presented as a destructive, radiolucent mandibular lesion composed of mesenchymal cells, some with unique multi-lobed nuclei, frequently arranged in a reticular pattern and supported by a myxoid stroma with focal laminations. Production of odontogenic hard tissues was also seen. Because of their unique microscopic features, both cases were investigated by next-generation sequencing and found to harbor the same STRN::ALK oncogene fusion. To our knowledge, these cases represent the first report of an odontogenic tumor with a STRN::ALK gene rearrangement. We propose the possibility that this neoplasm could be separate from other known odontogenic tumors. Both patients were treated with surgical resection and reconstruction. The prognosis of patients with this entity is currently uncertain but shall become more apparent over time as more cases are identified and followed.

Developing Odontoma in the Mandible of an Eight-Year-Old Boy

Benign mixed odontogenic tumors have been repeatedly classified and reclassified over the past few decades. Odontoma is considered a hamartoma due to its slow growth and non-aggressive nature. We present an interesting case of developing odontoma in an eight-year-old boy. His complaint was a slow-growing swelling in the lower right back tooth region. Clinical examination revealed a carious deciduous second molar. The orthopantomogram revealed a well-defined radiolucency around the unerupted mandibular first premolar and impacted mandibular second premolar. Histopathology revealed an odontogenic epithelial lining overlying myxofibrous stroma with inflammatory cells and calcified structures with few odontogenic rests. Special staining methods including Van Gieson and modified Gallego stains led to the final diagnosis of a developing odontoma.

Ameloblastic Fibro-Odontoma: A Journey of Progression?

A 19-year-old male patient reported to dental OPD of our institution with a swelling in the posterior part of the mandible on the left side. The patient gave a history of gradual increase in the size of swelling for 7 years. The patient also had a radiograph and histopathology slides from his previous dental visit at another facility. The radiograph revealed a well-circumscribed radiolucency with an impacted tooth (38). Histopathology slides showed features of an ameloblastic fibroma (AF). The patient had deferred the treatment for 5 years since he was young and reported to our OPD due to increase in the size of the swelling over the past few weeks. The present radiographs revealed radiolucency with radiopacity. Excisional biopsy was performed and the histopathological examination revealed an Ameloblastic fibro odontoma. This case report is to document and highlight the possible progression of AF to Ameloblastic fibro-odontoma.

Mixed odontogenic tumors: A review of the clinicopathological and molecular features and changes in the WHO classification

BACKGROUND

Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors, and controversy exists in the classification of cases presenting hard-tissue production: Ameloblastic fibrodentinoma (AFD) and ameloblastic fibro-odontoma (AFO). These cases are currently considered “developing odontomas” (hamartomatous lesions).

AIM

To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification.

METHODS

An electronic literature search was performed in the PubMed/MEDLINE database. An electronic search of the English language literature was performed and last updated in September 2020 in the PubMed/MEDLINE database using the following terms: “ameloblastic fibroma”, “ameloblastic fibrodentinoma”, “ameloblastic fibro-odontoma”, “ameloblastic sarcoma”, “ameloblastic fibrosarcoma”, “ameloblastic fibrodentinosarcoma”, “ameloblastic fibroodontosarcoma” and “odontogenic carcinosarcoma”. The inclusion criteria were odontogenic tumor series, case reports and systematic reviews that provided sufficient clinical, radiological and microscopic documentation to confirm the diagnosis.

RESULTS

The database search strategy resulted in 947 papers. Articles focusing on other topics, articles that were not in English, duplicate articles, and articles without fulfilling the inclusion criteria were excluded. Finally, 96 publications were included in this review to describe and discuss the main features of the searched entities. Several aspects of AFO and AFD, such as biological behavior, age of occurrence, amount of hard tissue, and potential for malignant transformation into odontogenic sarcomas, support the neoplastic nature in most of the reported cases. Considering the clinical, radiographic, histopathological and molecular characteristics of odontogenic lesions with hard tissue production, we suggest that these types of lesions should continue to be recognized as odontogenic tumors by maintaining the classically used terms.

CONCLUSION

This recommendation will be relevant for future clinical, microscopic, and molecular studies to better understand the biology of these interesting odontogenic tumors.

Developing odontoma arising from calcifying odontogenic cyst: A case report

Developing odontoma is a rare mixed odontogenic tumor that can arise with other odontogenic lesions. The association of COC with ameloblastic fibro-odontoma is extremely rare. We report an extremely rare case of developing odontoma arising from a calcifying odontogenic cyst in a 17-year-old girl.

Ameloblastic fibro-odontoma or complex odontoma masquerading as gingival enlargement

Ameloblastic fibro-odontoma is a rare tumor affecting the pediatric population and young adults. The World Health Organization (WHO) in 2005 defined it as “A neoplasm composed of proliferating odontogenic epithelium in a cellular ectomesenchymal tissue with varying degrees of inductive changes and dental hard tissue formation.” There exists a controversy on its histogenesis designating it as a hamartoma (developing complex odontoma [CO]) or a true neoplasm since both the lesions appear similar histologically. Recently, the WHO in 2017 has clubbed both these lesions as the same entity. Most cases are reported in males and in mandible, while cases in maxilla are scarce. This article describes a recurrence of a previously reported case of ameloblastic fibroma which showed maturation into AFO or CO in a girl aged 6 years in the posterior maxilla. This case is reported due to its rarity and a brief review with differential diagnosis is also discussed.

Ameloblastic Fibro-Odontoma: At the Crossroad Between "Developing Odontoma" and True Odontogenic Tumour

Ameloblastic fibro-odontoma (AFO) is a controversial, rare benign mixed odontogenic tumour that was re-defined as "developing odontoma" in the 2017 WHO classification arguing that once dental hard tissues form, it is programmed to transform into odontoma. However, AFO still remains unclear in terms of its nature. We aimed to analyze a large series of AFOs and compare it to a large series of odontomas (ODs) in an attempt to set cut-off diagnostic parameters between these entities and discuss latest updates on AFO histopathologic, clinical and molecular features. A total of 23 well-documented AFOs were analyzed versus 310 ODs focusing on the age of the patients and size of the lesions. For AFO, mean age was 9.4 ± 3.9 years (range 3-16 years) and mean size (greatest diameter) was 2.9 ± 1.5 cm (range 0.8-5.5 cm). For OD-mean age was 26.5 ± 15.6 years (range 3-81 years), mean size 1.9 ± 0.9 cm (range 1-5 cm). Receiver operating curve (ROC) showed that a cut-off age of 13.5 years and below [area under the curve (AUC) 0.902, 95%CI 0.859-0.945; p < 001; sensitivity 80%, specificity 87%] and a cut-off size of 2.1 cm and above are likely to be associated with AFO (AUC 0.7, 95%CI 0.574-0.827; p = 0.001; sensitivity 57%, specificity 77%). Thus, the combination of age and lesion size may be used to distinguish between lesions of a true neoplastic nature (i.e., AFO) and hamartomatous formation (i.e., OD). Further molecular and genetic specifications are needed to provide a better understanding on the pathogenesis of AFO in support of our suggestion and aid in an accurate classification of AFO.

Odontogenic and Developmental Oral Lesions in Pediatric Patients

This article reviews odontogenic and developmental oral lesions encountered in the gnathic region of pediatric patients. The process of odontogenesis is discussed as it is essential to understanding the pathogenesis of odontogenic tumors. The clinical presentation, microscopic features, and prognosis are addressed for odontogenic lesions in the neonate (dental lamina cysts/gingival cysts of the newborn, congenital (granular cell) epulis of the newborn, melanotic neuroectodermal tumor, choristoma/heterotopia, cysts of foregut origin), lesions associated with unerupted/erupting teeth (hyperplastic dental follicle, eruption cyst, dentigerous cyst, odontogenic keratocyst/keratocystic odonogenic tumor, buccal bifurcation cyst/inflammatory collateral cyst) and pediatric odontogenic hamartomas and tumors (odontoma, ameloblastic fibroma, ameloblastoma, adenomatoid odontogenic tumor, primordial odontogenic tumor). Pediatric odontogenic and developmental oral lesions range from common to rare, but familiarity with these entities is essential due to the varying management implications of these diagnoses.

Targeted Next-Generation Sequencing and Allele-Specific Quantitative PCR of Laser Capture Microdissected Samples Uncover Molecular Differences in Mixed Odontogenic Tumors

The molecular pathogenesis of mixed odontogenic tumors has not been established, and understanding their genetic basis could refine their classification and help define molecular markers for diagnostic purposes. Potentially pathogenic mutations in the component tissues of 28 cases of mixed odontogenic tumors were assessed. Laser capture microdissected tissue from 10 ameloblastic fibromas (AF), 4 ameloblastic fibrodentinomas (AFD), 6 ameloblastic fibro-odontomas (AFO), 3 ameloblastic fibrosarcomas (AFS), and 5 odontomas (OD) were screened by next-generation sequencing and results confirmed by TaqMan allele-specific quantitative PCR. BRAF p.V600E mutation in the mesenchymal component was shown in 4 of 10 AF (40%), 2 of 4 AFD (50%), 2 of 6 AFO (33%), and 2 of 3 AFS (67%), whereas all 5 OD were wild type for BRAF p.V600E. Mutation in the epithelial component was only observed in one AF and one AFO. One AFS contained an area of benign AF, and the mesenchymal component of both (AFS and AF) contained BRAF p.V600E, supporting the concept of malignant progression from a benign AF precursor. KDR, TP53, KIT, and PIK3CA single-nucleotide polymorphisms are reported. In conclusion, AF, AFD, AFO, and AFS show BRAF p.V600E in their mesenchymal component, unlike OD, which are BRAF wild type, suggesting that at least a subset of AF, AFD, and AFO are molecularly distinct from OD, and may represent distinct entities and be neoplastic.

Ameloblastic fibro-odontoma associated with paresthesia of the chin and lower lip in a 12-year-old girl

Ameloblastic fibro-odontoma is a rare, benign, and slowly growing neoplasm of the jaw composed of proliferating odontogenic epithelium in ectomesenchymal tissue along with dental hard tissue formation. Herein, we describe a case of an ameloblastic fibro-odontoma in 12-year-old female with paresthesia of the chin and lower lip. Panoramic radiography showed a radio-opacity in the right posterior mandible near the mandibular canal and associated with the right mandibular third molar. Histologically, the lesion contained epithelial and mesenchymal odontogenic components in close proximity to odontoma-like elements. Enucleation and curettage of the affected site in the mandible resulted in resolution of the paresthesia postoperatively.

Ameloblastic Fibro-Odontoma in an Adolescent: A Case Report and Review of Literature

Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor with the histologic features of ameloblastic fibroma (AF) but also contains enamel and dentin. It is most commonly observed in the pediatric population. Distinction between AFO and AF becomes important as ameloblastic fibromas are associated with higher recurrence rates of up to 18%, and 35% of these recurrent lesions can undergo malignant transformation to ameloblastic fibrosarcoma. Hence, for amelobastic fibroma, conservative curettage is recommended for the initial lesion and marginal resection is considered for recurrent cases. In contrast, AFO can be treated with simple curettage and the recurrence rate is approximately seven percent. Malignant transformation of AFO is exceedingly rare. Therefore, the treatment and prognosis differs for these two histologically similar neoplasms. We present a case of a 17-year-old boy who was initially diagnosed with ameloblastic fibroma upon biopsy, with subsequent curettage specimen showing AFO, which carries a better prognosis.

A Rare Case of Ameloblastic Fibro-Odontoma of Mandible with Literature Review

Ameloblastic fibro-odontoma (AFO) is a benign, mixed odontogenic tumor of epithelial and mesenchymal origin. It is predominantly seen in the younger age group, with delayed or altered eruption of teeth. Being clinically asymptomatic, this is identified incidentally during routine radiographic examination. Although considered to be nonaggressive with minimal tendency for recurrence, AFO requires surgical excision with long-term follow-up. This paper presents a rare case report of an 11-year-old boy, who was provisionally diagnosed with complex odontoma and later turned out to be AFO of the mandible.

Ameloblastic Fibro-Odontoma of the Maxilla in a Pierre-Robin Sequence Patient

INTRODUCTION

Pierre Robin sequence (PRS) is a rare disorder classically observed as a triad of features including micrognathia, glossoptosis, and upper airway obstruction. It is associated with a syndrome in about 60% of cases. While odontogenic tumors are common findings in patients with familial adenomatous polyposis and nevoid basal cell carcinoma syndromes, PRS has not been found to be consistently associated with any tumors of the jaw.

CASE REPORT

The current report aims to describe a patient with PRS who presented with an extensive ameloblastic fibro-odontoma (AFO) of the maxilla.

CONCLUSION

Continued observation for odontogenic tumors in PRS is necessary.

Three-Dimensional Printing Model as a Tool to Assist in Surgery for Large Mandibular Tumour: a Case Report

Objectives

Recently, three-dimensional printing models based on preoperative computed tomography and magnetic resonance imaging images have been widely used in medical fields. This study presents an effective use of the three-dimensional printing model in exploring complex spatial relationship between the tumour and surrounding tissue and in simulation surgery based planning of the operative procedure.

Material and Methods

The patient was a 7-year-old boy with ameloblastic fibro-odontoma. Prior to surgery, a hybrid three-dimensional printing model consisting of the jaw bone, the tumour and the inferior alveolar nerve was fabricated. After the simulation surgery based on this model, enucleation of the tumour, leaving tooth 46 intact (Universal Numbering System by ADA) safe, was planned.

Results

Enucleation of the tumour was successfully carried out. One year later, healing was found to be satisfactory both clinically and radiographically.

Conclusions

The study presented an effective application of a novel hybrid three-dimensional printing model composed of hard and soft tissues. Such innovations can bring significant benefits, especially to the field of oncological surgery.

Diverse calcification patterns of ameloblastic fibro-odontoma on radiographic examination

The occurrence of ameloblastic fibro-odontoma (AFO) in the oral region is unusual and accounts for 1-3% of all odontogenic tumors. AFO presents mixed radiopaque patterns within the lesion with diverse findings; therefore, it is important to compare this tumor with other odontogenic tumors that radiographically present with calcified bodies. Herein, we observed the calcification patterns within the lesion in seven AFO cases (five males, two females; mean age, 8.3 years; age range, 4-13 years). Periapical and panoramic radiographs were obtained from all seven cases. Five cases underwent conventional computed tomography (CT) scanning, and one underwent cone beam CT. Classification of the calcifications primarily involved the following two characteristics on the X-rays: appearance and location of the lesions. All seven cases were located in the molar regions of the mandible in association with impacted teeth. The calcification patterns of these AFOs were mixed or inhomogeneous within the lesion with various findings, including complex odontoma-like calcifications. However, the patterns differed between panoramic radiography and CT in some cases. The radiolucent lesions in AFO demonstrated varying calcification patterns and were associated with impacted teeth on the CT images.(J Oral Sci 58, 533-537, 2016).

Extensive Mandibular Ameloblastic Fibro-Odontoma

Ameloblastic fibro-odontoma (AFO) is a mixed odontogenic tumor that presents epithelial and mesenchymal components. Ameloblastic fibro-odontoma is generally diagnosed between the first and second decades of life and normally shows a slow clinical growth in the posterior portion of the maxilla or mandible, being mostly associated with 1 or more impacted teeth. Radiographic features of AFO show a radiolucent well-defined, uni, or multilocular defect due to containing variable amounts of calcified material. The enucleation of the tumor is the usual conduct and should be followed up for a long period of time. Here, the authors report the case of 17-year-old male patient who presented an extensive AFO on the right posterior side of the mandible. The panoramic radiograph and the tomographic examination revealed a multilocular radiolucent lesion with impacted teeth. Histological examination revealed connective tissue resembling the dental papilla along with epithelial strands or islands, as well as dental hard tissue such enamel and dentin. Enucleation and curettage was performed and led to good outcome. There was no recurrence after an 8-year follow-up, and oral rehabilitation was performed with dental implants.

Ameloblastic Fibro-Odontoma in a 4-Year-Old Boy

Introduction

Ameloblastic fibro-odontoma (AFO) is defined as a benign odontogenic tumor with slow growing behavior. Its prevalence is rare. AFO is characterized by histologic features of ameloblastic fibroma (AF) with the formation of enamel and dentine.

Case Presentation

This is a case report of AFO accompanied with a number of impacted deciduous teeth and its management in a 4-year old boy. Examination of oral cavity revealed an extensive swelling from midline to left deciduous maxillary first molar, covered with normal mucosa. Radiographic examination showed a well-defined mixed radiolucent-radiopaque lesion that extended horizontally from midline to mesial border of the left maxillary primary first molar and vertically from alveolar crest to the floor of nose. The differential diagnosis was odontoma (ameloblastic fibro-odontoma, complex odontoma). Surgical enucleation and curettage was performed under general anesthesia. Histopathologic sections show bone trabeculae in marrow spaces. There was myxoid matrix in some spaces which contained odontogenic epithelial cells. These findings led to diagnosis of AFO. No sign of recurrence has been observed during the 12-month follow-up period.

Conclusion

Although AFO is a rare tumor, it is more prevalent in childrenʼs jaw. Conservative surgical treatment allowed the normal development of teeth.

Large ameloblastic fibro-odontoma in a 7-year-old girl with analysis of 108 cases

BACKGROUND

Odontogenic tumors such as ameloblastic fibro-odontoma (AFO) are rare conditions in children and are often asymptomatic. AFOs are found by routine clinical and radiological examination or when they cause obvious intra- or extra-oral swelling.

MATERIALS AND METHODS

A case of an AFO in a 7-year-old girl is described, and 107 cases from the literature and this report are analyzed.

RESULTS

The total of 108 cases revealed the average age at presentation of AFO to be 6.3 years in boys and 9.6 years in girls. There was a slight male predilection and AFO lesions most often occurred in the posterior mandible. AFO was almost always associated with an unerupted tooth or teeth.

CONCLUSIONS

While the recurrence rate of AFO was found to be 5.5%, long-term postoperative clinical and radiological follow-up is advised to ensure no future signs of aggressive recurrence.

Defects of the Carney complex gene (PRKAR1A) in odontogenic tumors

The surgical treatment of some odontogenic tumors often leads to tooth and maxillary bone loss as well as to facial deformity. Therefore, the identification of genes involved in the pathogenesis of odontogenic tumors may result in alternative molecular therapies. The PRKAR1A gene displays a loss of protein expression as well as somatic mutations in odontogenic myxomas, an odontogenic ectomesenchymal neoplasm. We used a combination of quantitative RT-PCR (qRT-PCR), immunohistochemistry, loss of heterozygosity (LOH) analysis, and direct sequencing of all PRKAR1A exons to assess if this gene is altered in mixed odontogenic tumors. Thirteen tumors were included in the study: six ameloblastic fibromas, four ameloblastic fibro-odontomas, one ameloblastic fibrodentinoma, and two ameloblastic fibrosarcomas. The epithelial components of the tumors were separated from the mesenchymal by laser microdissection in most of the cases. We also searched for odontogenic pathology in Prkar1a(+) (/) (-) mice. PRKAR1A mRNA/protein expression was decreased in the benign mixed odontogenic tumors in association with LOH at markers around the PRKAR1A gene. We also detected a missense and two synonymous mutations along with two 5'-UTR and four intronic mutations in mixed odontogenic tumors. Prkar1a(+) (/) (-) mice did not show evidence of odontogenic tumor formation, which indicates that additional genes may be involved in the pathogenesis of such tumors, at least in rodents. We conclude that the PRKAR1A gene and its locus are altered in mixed odontogenic tumors. PRKAR1A expression is decreased in a subset of tumors but not in all, and Prkar1a(+) (/) (-) mice do not show abnormalities, which indicates that additional genes play a role in this tumor's pathogenesis.

Pigmented ameloblastic fibro-odontoma: clinical, histological, and immunohistochemical profile

Ameloblastic fibro-odontoma (AFO) is a slow-growing, expansive, benign odontogenic tumor, composed of ameloblastic epithelium embedded in an ectomesenchymal stroma resembling dental papilla, containing hard dental tissue in variable degrees of maturation, including enamel, dentin, and sometimes cementum. AFO typically affects the posterior mandible, causing bony expansion. We report a case of pigmented AFO in a 5-year-old boy, comprising clinical and histological features illustrated by immunohistochemistry using a large panel of antibodies, polarized light microscopy and scanning electron microscopy.

Ameloblastic carcinoma with features of ghost cell odontogenic carcinoma in a patient with suspected Gardner syndrome

Ameloblastic carcinoma and ghost cell odontogenic carcinoma are rare malignancies arising in odontogenic epithelium within the jaws. Gardner syndrome is a multifaceted autosomal dominant condition, which results in multiple dentofacial anomalies along with premalignant colon polyp formation and tumor formation in the skin and other organs. We report a case of ameloblastic carcinoma with features of ghost cell odontogenic carcinoma and extensive clear cell change and melanin pigmentation in a patient with clinical features of Gardner syndrome. To the best of our knowledge, odontogenic carcinoma arising in a patient with features of Gardner syndrome has not been reported previously. The clinical, radiographic, and histologic features of the case are discussed along with a review of the relevant literature.

A peripheral ameloblastic fibro-odontoma in a 3-year-old girl: case report, immunohistochemical analysis, and literature review

Ameloblastic fibro-odontoma (AFO) predominantly occurs in the jaw bones of children and young adults. Extraosseous AFO is extremely rare. We describe a peripheral ameloblastic fibro-odontoma in the maxillary gingiva of a 3-year-old girl. The clinical appearance resembled fiery red reactive gingival lesions. The histopathological examination of the excised lesion showed small islands and cords of odontogenic epithelium with cellular myxoid stroma in the subepithelial tissue. The mass contained calcified material and an enamel-like deposit. Many small blood vessels appeared in the connective tissue surrounding the odontogenic epithelium. The immunohistochemical assays showed strong reactivity for amelogenin, β-catenin, CD44, and CD31 in the tissue sections. There was no recurrence after the 1-year follow-up. Because this lesion clinically resembles other nonneoplastic lesions and is very rare in gingiva, establishing a correct diagnosis is achieved only based on specific histological characteristics. Conservative excision of the tumor is the treatment of choice.