Unicystic ameloblastoma: Analysis of 370 cases in a single center in Sri Lanka

Unicystic ameloblastoma: A retrospective study on recurrent factors from a single institute database

OBJECTIVE

Unicystic ameloblastomas are a variant of ameloblastoma with a definite recurrence rate because of the biological behaviours of the tumour. The risk factors associated with disease recurrence were analysed in this retrospective study.

METHODS

A total of 132 patients with primary unicystic ameloblastoma reported in a tertiary hospital from 2005 to 2015 were analysed to identify the clinic-pathological and radiological factors associated with recurrence using univariate and multivariate Cox regression analyses.

RESULTS

The mean volume was 30.54cm3 ± 12.55 cm3, and this value differed significantly according to recurrence (p < 0.001). Root resorption and bone cortex/soft tissue invasion were also significantly associated with recurrence among unicystic ameloblastoma patients (p = 0.017 vs. p < 0.001, respectively). A new stage classification system was developed to predict disease recurrence of patients. The multivariate Cox regression analysis revealed that the new stage classification system was the only predictor of disease recurrence in unicystic ameloblastoma patients (p < 0.001), regardless of root resorption, position and site characteristics.

CONCLUSIONS

Volume, root resorption and bone cortex/soft tissue invasion were risk factors for disease recurrence among unicystic ameloblastoma patients. The new stage classification was an independent predictor of disease recurrence in patients with unicystic ameloblastoma.

Pediatric Odontogenic Tumors

Odontogenic tumors are rare tumors of the jaws that arise from remnants of the tooth forming apparatus. Some odontogenic tumors demonstrate strong predilection for pediatric patients including the unicystic ameloblastoma, adenomatoid odontogenic tumor, ameloblastic fibroma, ameloblastic fibro-odontoma, odontoma, and primordial odontogenic tumor. In this review, we discuss the clinical, radiographic, histopathologic, and molecular characteristics of select odontogenic tumors that demonstrate pediatric predilection and review management.

A conservative approach for unicystic ameloblastoma: Retrospective clinic-pathologic analysis of 12 cases

BACKGROUND

Unicystic ameloblastoma is an encapsulated odontogenic neoplasm with a single cyst cavity. The conservative or aggressive surgical approaches used to treat the tumor directly affect recurrence rates. However, there is a lack of a standard protocol that can guide its management.

STUDY DESIGN

We retrospectively reviewed the clinicopathological findings and therapeutical procedures of 12 unicystic ameloblastoma cases treated by the same surgeon during the past 20 years.

METHODS

All cases of unicystic ameloblastoma diagnosed by biopsy and treated by the same surgeon between 2002 and 2022 were reviewed. Eligibility criteria were patients with completely filled-out charts containing the follow-up period and confirmation of the diagnoses based on the microscopic findings of the whole excised specimens. Data collected were categorized into clinical, radiographic, histological, surgical, and recurrence aspects.

RESULTS

There was a female predilection (2:1), and ages ranged between 18 and 61 years (mean: 27.25, ±12.45). Almost all (92%) affected the posterior mandible. Radiographically, the mean length of the lesions was 46.14 mm ± 14.28 mm which 92% were unilocular and 8.3% multilocular. Root resorption (n = 7, 58%), tooth displacement (n = 9, 75%), and cortical perforation (n = 5, 42%) were also observed. The mural histological subtype corresponded to 9 (75%) of the cases. The same conservative protocol was performed in all cases. The follow-up period ranged between 12 and 240 months (~62 ± 65) and recurrence occurred in only one patient (8%).

CONCLUSION

Our findings suggest a conservative approach should be the first option for unicystic ameloblastoma treatment, even for those with mural proliferation.

Cystic Lesions of the Jaws: The Top 10 Differential Diagnoses to Ponder

BACKGROUND

Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that may be reactive or neoplastic in nature. While most cystic jaw lesions are benign, variability in biologic behavior makes distinction between these entities absolutely crucial.

METHODS

Review.

RESULTS

Two clinical cases are presented in parallel and are followed by an illustrated discussion of the ten most likely differential diagnoses that should be considered when confronted with a cystic jaw lesion. Strong emphasis is placed on the histologic differences between these entities, empowering readers to diagnose them with confidence. Perhaps even more importantly, the more common diagnostic pitfalls in gnathic pathology are discussed, recognizing that a definitive diagnosis cannot be rendered in every situation. The histologic diagnoses for the two clinical cases are finally revealed.

CONCLUSION

Cystic lesions of the maxilla and mandible may be odontogenic or non-odontogenic. The most common cystic lesions are the reactive periapical cyst, and the dentigerous cyst (which is developmental in nature). It is important to note that cystic neoplasms also occur in the jaws, and that the presence of inflammation may obscure the diagnostic histologic features of lesions like odontogenic keratocyst and unicystic ameloblastoma. Ancillary testing is of limited diagnostic value in most scenarios. However, both clinical and radiographic information (such as the location, size, duration, associated symptoms, and morphology of the lesion in its natural habitat) are significantly useful.

Maxillary unicystic ameloblastoma: a rare presentation

Unicystic ameloblastoma (UAM), a rare variant of ameloblastoma, is an odontogenic epithelial neoplasm typically appearing in the mandible. We report an extremely rare case of maxillary UAM with an impacted canine and supernumerary tooth. The patient was a woman in her late 30s who presented with a slight expansion of the left anterior maxilla due to a cystic lesion with impacted teeth. Under a clinical diagnosis of dentigerous cyst, the cystic lesion was completely enucleated by extracting the impacted teeth. Based on the clinical features and pathological findings, the final diagnosis was intraluminal UAM in the anterior maxilla. In the present case, despite the rarity of UAM with impacted teeth in the anterior maxilla, it should be considered during differential diagnosis. Careful clinical examination is required for diagnostic accuracy since the clinical findings of tooth-containing ameloblastoma and dentigerous cyst are very similar.

Fibular Free Flap and Iliac Crest Free Flap Mandibular Reconstruction In Patients With Mandibular Ameloblastomas

ABSTRACT

Ameloblastoma (AM) is the most common, locally aggressive odontogenic tumor. It comprises about 1% of all head and neck neoplasms. It occurs mainly in young adults in their 3rd and 4th decade of life. It localizes in the mandible in about 80% of the cases. According to the 2017 WHO classification, 4 types of ameloblastoma can be distinguished: ameloblastoma (previously referred to as solid/multicystic-SMA; the "conventional type" AM), unicystic (AM-UA), extraosseous/peripheral (AM-PA), and malignant/metastatic (AM-MA). Solid, multicystic is the most common type. It is characteristic for its aggressiveness and high risk of recurrence. Radical resection with consecutive reconstruction is the treatment of choice of mandibular ameloblastomas.In this study, the authors present their experience in the surgical treatment of mandibular ameloblastomas with vascularized free flap reconstructions. They discuss new technological possibilities that could improve the precision of the reconstructive procedure and therefore result in the better aesthetic outcome.The retrospective study of a group of 21 patients suffering from mandibular ameloblastoma who underwent segmental mandibulectomy with simultaneous microvascular free flap reconstruction was conducted. A thorough clinical analysis with various aspects was performed. Tumors resected before 2017 were double checked patomorphologically and assigned to the corrected subtype group.Seven patients were admitted to the department due to recurrent ameloblastoma. The most common localization of the tumor was the mandibular body (n = 6) and body with ramus of the mandible (n = 6). A total amount of 10 iliac crest free flaps and 12 fibular free flaps were performed. Complications were reported in 4 patients. A purulent oro-cutaneus fistula occurred in 3patients. There was a flap failure in each reconstructive group. The virtual surgical planning with intraoperative cone-beam computed tomography was used in 3 patients. Dentition implantation was conducted in 4 patients (3 simultaneously, 1 postponed). The mean follow-up was 5 years and 8 months.Radical resection that covers radical segmental mandibulectomy with immediate microvascular free flap reconstruction is a first-line and only effective treatment of mandibular ameloblastomas, that eliminates the risk of recurrence. The extent of surgical margins seems not to influence the recurrence rate, yet further investigation with statistical analysis should be performed. The choice of the adequate free flap must be adapted to dimensions and localization of the tumor and to each patient individually.New technologies such as virtual surgical planning with 3D models and intraoperativecone-beam computed tomography can make the reconstruction more accurate, improving patient's quality of life.

Unicystic ameloblastoma: analysis of surgical management and recurrence risk factors

Unicystic ameloblastoma is a distinct pathological variant with varying evidence published about its behaviour and surgical management. Due to a paucity of large studies in the literature with long-term follow up, the aim of this study was to analyse its surgical management and identify clinicopathological features associated with recurrences. All histopathologically confirmed lesions diagnosed at two referral centres between 1995 and 2020 were retrospectively analysed. Demographic, clinical, radiological, and histopathological features were analysed along with surgical methods and follow-up data. Univariate regression analyses were performed to identify risk factors for recurrence. Sixty-three patients were included in the study with mean age of 26.3 years and a male to female ratio of 1:0.75. The majority of lesions occurred in the posterior mandible (57.1%) and were unilocular (88.9%). Most lesions were managed with enucleation followed by application of Carnoy's solution (ferric chloride: 1g; chloroform: 3 mL; glacial acetic acid: 1 mL; ethyl alcohol 96%: 6 mL) and burring of the peripheral bone margin which resulted in the lowest recurrences (9.1%) besides resection. Significantly associated clinicopathological features with recurrences included patients who were male, large lesions (>90 mm), presence of root resorption, cortical perforation, mural subtype, and retention of associated teeth. In conclusion, decision making in the management of unicystic ameloblastoma should be based on the clinicopathological features and not be solely based on the histopathological subtype. Enucleation followed by application of Carnoy's solution and burring of the peripheral bone margin was demonstrated to be the least invasive method with an acceptable low recurrence rate.

Association of clinicopathological factors and treatment modalities in the recurrence of ameloblastoma: Analysis of 624 cases

BACKGROUND

Ameloblastoma is an odontogenic tumour exhibiting locally invasive behaviour and high recurrence rate after treatment. Conventional ameloblastoma is reportedly been more aggressive showing infiltrative growth patterns and a tendency for recurrence. This is a retrospective study performed to analyse the relationship between clinicopathological characteristics and treatment modalities in the recurrence of ameloblastoma.

METHODS

624 cases of ameloblastoma comprising of 519 non-recurrent ameloblastoma and 105 recurrent ameloblastoma from two main diagnostic centres in Malaysia and Sri Lanka were included. The demographic data, clinical characteristics, histopathological data, treatment modality and episodes of recurrence were extracted and analysed.

RESULTS

The mean age for recurrent ameloblastoma was 37.23 with a peak occurrence in the third decade of life. Recurrent ameloblastoma was marginally female predominant with male to female ratio of 1:1.3. Mandible was the commonest site for the recurrence with a predilection for more than two segments of left mandible followed by left posterior mandible. Follicular (58.1%) histopathological variant was the most reported type to recur followed by plexiform (17.1%). 49.5% of recurrent cases were treated with conservative approach. 65.7% of recurrent cases demonstrated a single episode of recurrence. Mixed (follicular and plexiform) histopathological variants showed the longest average years (11.5 years) for the single episode of recurrence. Plexiform ameloblastoma treated with conservative approach recurred in the shortest follow-up period. The recurrence of ameloblastoma was significantly associated with age group, sub-site of occurrence and histopathological variants (p<0.05).

CONCLUSION

This study showed that age, sub-site of occurrence and histopathological variants are significant factors responsible for the recurrence of ameloblastoma.

Central giant cell granuloma mimicking a periapical lesion of endodontic origin: A case report

This paper aims to report a case in which central giant cell granuloma (CGCG) mimicked a periapical lesion of endodontic origin. An 18-year-old female patient was referred for diagnosis and treatment of extensive radiolucent periapical lesion involving 31, 32, 33, 34 and 35 teeth. Clinically, the patient presented slight facial asymmetry and healthy teeth on the affected side with positive response to thermal vitality tests. Thus, an incisional biopsy was performed, which presented a histopathological picture characteristic of a CGCG. The endodontic treatment of the involved teeth was followed by surgical curettage of the lesion. After two years of follow-up, the patient was asymptomatic, with marked improvement in mandibular symmetry and adequate healing of the lesion. Therefore, the diagnosis of radiolucent periapical lesions must include lesions of endodontic and non-endodontic origin for better treatment planning and execution.

Hybrid ameloblastoma and central giant cell lesion: Challenge of early diagnosis

Hybrid lesions encompass the occurrence of different entities in one lesion. A 67-year-old woman was referred to the Oral and Maxillofacial Surgery Service for treatment of mandibular Central Giant Cell Lesion (CGCL) previously diagnosed. Intraoral examination revealed edentulism and a painless swelling extending from the alveolar ridge to the buccal vestibule with hard consistency covered by normal mucosae, with unknown duration. Panoramic radiograph revealed a large, multilocular and well-defined radiolucent lesion extending from the region of left mandibular lateral incisor teeth to right mandibular first molar with no evidence of osseous perforation. Initially, a treatment with intralesional injection of corticosteroids was performed. After 18 months of treatment, an increase in size of the osteolytic lesion was noted. An incisional biopsy was carried out and the microscopic examination revealed a unicystic ameloblastoma associated to CGCL. It was performed marsupialization and later the enucleation of residual lesion. The follow-up remains being performed.

Key words:Hybrid lesion, central giant cell lesion, ameloblastoma.

Adenoid ameloblastoma in the posterior maxilla: a case report and review of the literature

INTRODUCTION

Adenoid ameloblastoma is a rare benign odontogenic tumor that favors a slight predilection for male patients, fourth and fifth decades of life, and posterior regions of the jaws. To date, less than 40 cases have been reported in the English language literature. The radiographic aspects of adenoid ameloblastoma vary from unilocular and well-defined lesions to diffuse and multilocular lesions. Most of the lesions exhibit a radiolucent image and are usually large, with a mean size of 3.5 cm. Microscopically, pseudoductal structures composed of columnar cells in a palisaded arrangement formed from the parenchyma of the tumor were observed.

CASE PRESENTATION

We describe a case of adenoid ameloblastoma in a 54-year-old woman, who presented with no symptoms. Panoramic radiography showed a well-circumscribed, unilocular radiolucency in the left posterior maxilla.

CONCLUSION

As odontogenic tumors are rare, some entities are infrequently encountered, making the diagnosis more difficult. Clinicians, oral and maxillofacial surgeons and oral pathologists should be familiar with the adenoid ameloblastoma and its differential diagnosis for accurate diagnosis and management.

Conservative management is effective in unicystic ameloblastoma occurring from the neonatal period: A case report and a literature review

Unicystic ameloblastoma (UA), a benign odontogenic tumor of the jaw, represents less than a third of all ameloblastomas and seems less aggressive than other types of ameloblastoma. We present here the first case of UA that developed prenatally and was successfully managed in the early neonatal period with marsupialization and curettage performed carefully to avoid injury to the tooth germ. BRAF and SMO mutations were not detected. After 2 years of follow-up, complete reossification and normal eruption of deciduous teeth were noted, and there was no recurrence of UA. We recommend conservative treatment of UA in the pediatric population to avoid loss of and/or injury to the tooth germ, provided close follow-up is carried out all through the individual's growth for early detection of potential recurrences, growth impairments, or tooth eruption disorders. The intratumoral somatic mutational status of BRAF, SMO, RAS family, and FGFR2 may help determine personalized targeted treatment, particularly in case of recurrence.

Successful conservative treatment of a mandibular unicystic ameloblastoma: 13-year follow-up

Ameloblastoma is an uncommon, locally aggressive benign odontogenic tumor and can reach considerable dimensions causing facial deformity and functional impairment. They are characterized by local aggressiveness. It is recommended that maxillary ameloblastomas be treated aggressively due to proximity of various vital structures. Conservative treatments such as marsupialization, enucleation and curettage while preserving bone integrity seem to be associated with a high rate of recurrence. Treatment evaluation of ameloblastomas is a complex issue, as ideally it should not be so destructive due to the benign nature of this lesion, but should be extensive enough to avoid recurrences. The present study is about a clinical case of a 16-year- old man with a unicystic ameloblastoma treated successfully with marsupialization. Patient was followed up every 12 months. About 13 years after diagnosis, the patient is clinically healthy and radiographically it is possible to observe evidence of bone repair.

Key words:Odontogenic tumors, ameloblastoma, marsupialization, unicystic.