Diagnosis and treatment of the unicystic ameloblastoma

Two cases of unicystic ameloblastoma are presented. The lesions were pain-free and expanded the mandible. They were removed by curettage. Recurrent lesions had similar clinical appearances and histological pictures compared to the original lesions. The unicystic ameloblastoma manifested itself as a cystic cavity without solid neoplastic features, which differs from the solid ameloblastoma with regard to the age of the patients and the rate of recurrence. The behavior of the unicystic ameloblastoma was similar to that of the primordial cyst. Despite the obvious risk of recurrence, conservative treatment with enucleation and curettage seemed to be justified in preference to mutilating radical surgery.     

Comparison of long-term results between different approaches to ameloblastoma.

OBJECTIVE: The long-term results of different surgical approaches to ameloblastoma were compared to develop a more rational surgical approach to this tumor. STUDY DESIGN: Seventy-eight primary ameloblastomas, including 27 unicystic, 21 multicystic, and 30 solid-type tumors, were examined in this study. The methods of treatment consisted of radical surgery (ie, resection-both segmental and marginal) and conservative treatments (ie, marsupialization alone, marsupialization followed by enucleation with sufficient bone curettage if necessary, and enucleation with bone curettage). The effect of marsupialization on recurrence data after a follow-up period of at least 5 years was evaluated with respect to clinical type and histologic pattern. RESULTS: Marsupialization was performed in 31 cystic ameloblastomas before surgery, and the effective rate of marsupialization was 74.2%. Recurrence was observed in 7.1% (3/42) after radical surgery and in 33.3% (12/36) in conservative treatments. Relatively higher tendencies of recurrence were observed in the multicystic type and follicular and/or plexiform pattern tumors. CONCLUSIONS: Conservative treatments including marsupialization and enucleation followed by sufficient bone curettage were thought to be useful, reducing the need for jaw resection. This result extends the indications for conservative treatment of ameloblastoma.     

Use of gas combination cryosurgery for treating ameloblastomas of the jaw

This study evaluated the results of curettage followed by spray propane, butane, and isobutane gas combination cryosurgery in 10 patients with ameloblastoma. The patients' age ranged from 7 to 87 years (mean, 31 years), with equal prevalence in both men and women. Five cases were diagnosed as solid ameloblastomas and 5 as unicystic ameloblastomas. Before enucleation and cryosurgery, the unicystic lesions received marsupialisation to decrease their size. No patient showed evidence of clinical or radiographic recurrence, pathologic fracture, or infection after treatment with enucleation and cryosurgery. The most common complication was wound dehiscence, which was observed in all cases. The average follow-up period was 60.5 months (range 48–108 months). These results show that enucleation followed by cryosurgery is an effective therapy for managing ameloblastomas.     

彻底刮治术治疗下颌骨成釉细胞瘤的临床研究

目的:探讨彻底刮治术治疗下颌骨成釉细胞瘤的可能性。方法:选取临床中碰到的11例下颌骨成釉细胞瘤患者,采用彻底刮治术治疗,术后密切随访,观察患者术后有无复发及骨质是否得到恢复。结果:术后2年内,要求患者每3月进行1次复查并摄曲面体层片或CT检查,11例患者中仅有1人出现复发情况,另外10例患者术前术后CT或者曲面断层片的对比显示,骨质出现了再次生长的现象。结论:彻底刮治术治疗下颌骨成釉细胞瘤效果可观,临床可推广。     

Cystic ameloblastoma. A clinicopathologic analysis

Thirty-three cases of ameloblastoma arising from odontogenic cyst linings are presented. Lesions of this nature have been referred to as "unicystic ameloblastoma." Our data support the findings of others in that this lesion differs from the solid invasive varieties of ameloblastoma, as the former occurs in a younger age group and exhibits a low rate of recurrence following enucleation or curettage. On the basis of histopathologic features we provide evidence that these lesions represent mural and luminal ameloblastomatous change in a pre-existing cyst rather than cystic degeneration of a solid tumor.     

A modified surgical approach for the treatment of mandibular unicystic ameloblastoma in young patients

BackgroundUnicystic ameloblastoma is a distinct clinicopathological entity with its cyst-like radiographic appearance and occurrence in the mandible of young patients. Surgical resection of the mandible leads to jaw deformity and challenging reconstruction burden, especially among young patients. Conservative treatment, however, results in less serious function and esthetic impairment.PurposeWe aimed at evaluating dredging method as an alternative conservative surgical approach in young patient with large unicystic ameloblastoma.Patients and methodsTwenty patients (n=20) with histologically-diagnosed unicystic ameloblastoma were recruited for this prospective study. The surgical treatment protocol comprised an initial deflation (marsupialization) step, followed by later enucleation and subsequent repeated separate dredging procedures.ResultsThe study population comprised 16 males and 4 females. The average age at the time of diagnosis was 18.5 years. At the last follow-up period, achievement of normal mandibular bone contour with no radiographic signs of recurrence was evident.ConclusionThe dredging method as a modified surgical technique may represent a reliable approach for management of unicystic ameloblastoma in young patients.     

Ameloblastoma in children.

PURPOSE: The purpose of this report was 1) to report the experience of the University of Maryland, Department of Oral and Maxillofacial Surgery (OMS Department) in the treatment of ameloblastoma in children and 2) to review the world literature on the treatment of ameloblastoma in children from 1970 to 2001. METHODS AND MATERIALS: This study first reviews the experience of the OMS Department of the University of Maryland with ameloblastomas in children and then reviews the literature on this subject. The first part of the study was undertaken by a retrospective chart review of all patients with a diagnosis of ameloblastoma in the OMS Department between May 1991 and December 1999. The literature on ameloblastoma in Western societies and Africa was separately reviewed from 1970 through 2001. Reports earlier than 1970 were not reviewed, as the histologic diagnosis of ameloblastoma was not well defined before that period. RESULTS: In the Maryland series, 11 patients under the age of 20 years with ameloblastoma were treated. Eight patients were seen primarily, and 3 presented with recurrent lesions. The average age was 15.5 years; 5 of 11 patients were black, and 9 of 11 tumors were unicystic ameloblastomas. The literature review showed 85 children in the Western reports and 77 reported from Africa. The average ages were 14.3 and 14.7 years, respectively, but unicystic ameloblastomas accounted for 76.5% of the Western and only 19.5% of the African children, with an increased frequency of occurrence in the mandibular symphisis in African (44.2%) versus Western (5.8%) patients. Analysis of recurrence after enucleation of unicystic ameloblastomas in 20 children followed at least 5 years or until recurrence showed a recurrence of 40%. CONCLUSIONS: Ameloblastomas in children differ from adults, with a higher percentage of unicystic tumors. African children appear to resemble the adult pattern. Although enucleation has been claimed to give acceptable recurrence rates in unicystic ameloblastoma, there are no large series with long follow-up in children. The histologic pattern that exhibits mural invasion in unicystic ameloblastoma suggests that more aggressive surgery is necessary.     

Is there a role for enucleation in the management of ameloblastoma?

This study aimed to determine the appropriate long-term management for ameloblastoma and the role of enucleation in the management of the subtypes of ameloblastoma (solid ameloblastomas, cystic ameloblastomas and peripheral ameloblastomas). They differ in their degrees of aggressive behavior and recurrence rates. This is an evidence-based study with review of relevant articles from PubMed, EMBASE and the Cochrane Library. Articles were categorized for quality according to the Oxford Center of Evidence-Based Medicine (CEBM). 58 articles met the inclusion criteria; their evidence level varied from IIA to V. No randomized control trials were identified. Solid and multicystic ameloblastomas have a high recurrence rate (60–80%) with simple enucleation and require more aggressive treatment. The treatment of choice is resection with 1-cm margins. This may require segmental resection in the mandible, and partial maxillectomy in the maxilla. For the unicystic ameloblastoma recurrence rates are high for simple enucleation. The intraluminal subtype of unicystic ameloblastoma may do well with enucleation, but the intramural subtype may not, and since these cannot be identified preoperatively more aggressive treatment is recommended, including peripheral ostectomy or enucleation with subsequent treatment of the surrounding bone with liquid nitrogen, Carnoy's solution, or similar physicochemical modality. The peripheral ameloblastoma has a different origin and responds to local excision.     

Desmoplastic ameloblastoma: a systematic review of the cases reported in the literature

The aim of this study was to integrate the available data published on desmoplastic ameloblastoma (DA) into a comprehensive analysis of its clinical/radiographic features. As it is not clear whether the hybrid ameloblastoma has a unique biological behaviour, the clinical/radiographic features of conventional DA were compared with those of the hybrid variant. An electronic search was undertaken in May 2019. Eligibility criteria included publications with sufficient clinical/radiographic/histological information to confirm the diagnosis. A total of 128 publications reporting 285 DAs were included (246 central non-hybrid, 33 central hybrid, 6 peripheral). There was a statistically significant difference between non-hybrid and hybrid cases concerning lesion location, radiographic limits, and size. In contrast to non-hybrid tumours, which showed a similar distribution in the mandible and maxilla, hybrid tumours showed a high predominance of mandible location. Non-hybrid lesions more often showed ill-defined radiographic margins, and were smaller tumours than hybrid DAs. Enucleation with an additional therapy (either curettage or peripheral osteotomy) or resection led to a lower recurrence risk in comparison to curettage or enucleation without additional therapy. The location of the lesion and type of treatment are related to tumour recurrence. There are important differences in location and radiographic limits between hybrid and non-hybrid DAs, which support their classification as distinct lesions.     

92例上颌骨成釉细胞瘤不同手术方式的效果评价

目的:探讨上颌骨各型成釉细胞瘤合适的手术治疗方法.方法:回顾分析92例上颌骨成釉细胞瘤患者的临床资料,所有患者病理诊断明确,术后随访3～8年,定期拍摄颌面部CT、全景片,观察手术治疗效果.采用SPSS 22.0软件包对数据进行统计学分析.结果:上颌骨成釉细胞瘤男女比例为3∶1,男性较多,平均年龄为45.77岁.92例患...     

Clinical and radiologic behaviour of ameloblastoma in 4 cases

Ameloblastoma is a benign but locally aggressive epithelial odontogenic neoplasm. It represents 1% of all tumours of the jaw bone. In 80% of cases, it is localized in the mandibular molar and ascending ramus area, mostly associated with an unerupted tooth. It occurs over a wide range of ages (mean age is in the 20s or 30s) and with equal frequency in men and women. Ameloblastoma may be discovered during a routine radiographic examination or as a clinically observed developing mass. It has a characteristic, but not diagnostic, radiographic appearance. It can be treated by enucleation, bone curettage or wide resection. The rate of local recurrence is high when it is treated inadequately. We describe the clinical and radiologic behaviour of ameloblastoma and discuss treatment protocols and the possibility of conservative management of this tumour. Our results suggest the importance of long-term follow-up with various radiographic techniques.     

Bilocular unicystic ameloblastoma of the mandible in a 9 yr old child – A diagnostic and management dilemma

Unicystic ameloblastoma is a less encountered variant of the ameloblastoma that usually presented as unicystic lesions of jaw occurring in 3rd and 4th decades of life. It shows a typical ameloblastomatous epithelium lining the cyst cavity, with or without variable tumor proliferations. The case presented here is of a 9?yr old boy who was referred to our center for the management of a large diffuse swelling on the right side of the face. Clinical and radiologic evaluation showed two interconnected cystic lesions in the right body and the symphyseal regions of the mandible associated with impacted canines bilaterally. The initial histopathology of both cystic spaces showed the lesion to be dentigerous cysts and the results were reconfirmed in two other centers. A complete surgical enucleation of this bilocular cyst was done sparing the impacted teeth. The histopathologic examination of the post-operative specimen showed features of Unicystic Ameloblastoma. The patient was followed up on a regular basis for more than 3?years. There is no signs of recurrence and his latest radiographic examinations shows good bone formation. The impacted teeth are erupting into position. This case reports the difficulty in clinical diagnosis and the peculiar bilocular presentation of unicystic ameloblastoma which was conservatively managed by surgical enucleation of the complete lesion, sparing the dentition.     

单囊型成釉细胞瘤行开窗减压术联合刮治术的临床研究

目的:探讨开窗减压术联合刮治术治疗单囊型成釉细胞瘤的治疗效果和预后。方法:20例单囊型成釉细胞瘤行开窗减压术,术后佩戴超软热凝树脂塞治器,Ⅱ期行刮治术,术后严密随访,观察瘤腔变化。结果:锥形束CT显示病变范围明显缩小,病变区解剖结构接近正常。开窗术后3个月瘤腔平均缩小28.66%,术后6个月平均缩小58.51%,术后12个月平均缩小为79.33%,瘤腔面积与术前比较明显缩小(P<0.05)。术后6个月瘤腔骨密度冠状位、矢状位及水平位分别为371.32、361.74、384.71 Hu,术后12个月分别为517.64、523.22、521.05 Hu,与术前相比有明显差异(P<0.05)。术后12~24个月行二期刮治,随访3~5年无复发。结论:单囊型成釉细胞瘤行开窗减压术,术后佩戴超软热凝树脂塞治器能维持开窗口通畅,在瘤腔变化不明显时进行二期刮治术,是治疗单囊型成釉细胞瘤的一种有效方法。     

Recurrence related to treatment modalities of unicystic ameloblastoma: a systematic review

This systematic review aims to identify all studies pertinent to the clinical question, ‘which treatment for unicystic ameloblastoma results in the lowest recurrence rate?’ A structured systematic search of the literature, with predefined inclusion and exclusion criteria, using computer and manual searches as well as personal communication, was performed. Evaluations and critical appraisal were done separately in 3 rounds. All searches were performed by 2 independent judges and any disagreement was settled by discussion with a third party. Four treatment modalities for unicystic ameloblastomas were identified. The recurrence rates were 3.6% for resection, 30.5% for enucleation alone, 16% for enucleation followed by application of Carnoy's solution and 18% for marsupialization with/without other treatment in a second phase. It was concluded that there is only weak evidence showing that jaw resection resulted in the lowest recurrence rate, followed by enucleation with application of Carnoy's solution. Enucleation alone resulted in the highest recurrence rate and treatment by marsupialization cannot be sufficiently evaluated since most cases were followed by a second stage surgery of some kind.     

109例成釉细胞瘤病理类型、影像学表现、治疗方法和预后的对比研究

目的 对比研究成釉细胞瘤病理类型，影像学表现，治疗方法和预后之间的关系。方法 对109例成釉细胞瘤患者的病理分型，影像学表现，治疗方法和复发情况进行回顾性比较分析。结果 单囊型发病组多见于青少年，滤泡型和丛状型多见于青壮年组，滤泡型影像学特点为多房，房室大小不均，分隔多，囊腔局部或边缘多伴有蜂窝状表现，丛状型为多房大囊影，房室大小均一，分隔少，膨胀改变明显，少伴有蜂窝影，滤泡复发率高于其他各型。结论 成釉细胞瘤滤泡型，丛状型和单囊型在发病年龄，影像学表现各具特点，滤泡型复发率最高。     

Unicystic ameloblastoma--use of Carnoy's solution after enucleation

A retrospective analysis of 29 patients with a histologically confirmed diagnosis of unicystic ameloblastoma is reported with special emphasis on a treatment regime employing enucleation and application of Carnoy's solution. Despite the finding that 93% of lesions exhibited mural invasion, a recurrence rate of 10% after treatment is reported, suggesting a possible benefit of Carnoy's solution against recurrence.     

Histopathology of ameloblastoma of the jaws; some critical observations based on a 40 years single institution experience

The aim of the present study is to examine all cases of intraosseous benign ameloblastomas treated between 1970 and 2010 in a single institution and to look for a possible correlation between the histopathological aspects and the demographical and clinical parameters, as well as the treatment outcome. The data of a total number of 44 patients were retrieved from the records. Nine patients were excluded because of doubt about the correct diagnosis (8 patients) or because of an extra-osseous presentation (1 patient). No statistically significant differences were found between the histopathological (sub)types of ameloblastomas and the demographical and clinical parameters, nor between the histopathological (sub)types and treatment outcome. Of the 28 patients treated by enucleation, in 17 patients one or more recurrences occurred, with no significant predilection for any histopathological (sub)type, including the unicystic type. There were no significant differences in the recurrence rate after enucleation in patients below and above the age of 20 years either. In six out of 17 patients with a recurrence, the recurrent lesion showed a different histopathological subtype than was encountered in the primary. In two cases a change from solid/multicystic to desmoplastic ameloblastomas was noticed. In conclusion, the current histopathological classification of benign intraosseous ameloblastoma does not seem to have clinical relevance with the possible exception of the luminal unicystic ameloblastoma that has been removed in toto, unfragmented. Since no primary desmoplastic ameloblastomas were encountered in the present study no further comments can be made on this apparently rare entity.     

The epidemiology and management of ameloblastomas: A European multicenter study

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery.The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence.A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05).Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.     

Piezosurgical treatment of unicystic ameloblastoma

BACKGROUND: This case report describes a 22-year-old female who was referred with a radiolucent lesion between her mandibular right molars. The original radiographic image suggested an odontogenic cyst. METHODS: The surgical enucleation and osteotomy of the residual cavity were performed with a piezoelectric knife. Histologic analysis revealed the lesion was a unicystic ameloblastoma that showed no evidence of epithelial invasion in the connective tissue wall, and it appeared to be contained within the cystic cavity with an intraluminal projection showing features of an ameloblastoma. The patient refused any further surgical treatment. In consideration of the pathological result (no presence of invasive epithelial cells in the connective tissue wall of the cyst), a wait-and-see policy was proposed to the patient, with more extensive surgical treatment only if a recurrence was noted. RESULTS: The patient has been followed clinically and radiographically at 6-month intervals for 5 years. There have been no signs of recurrence. CONCLUSION: Therefore, the piezoelectric knife could be considered a promising device in the treatment of odontogenic tumors.