Immunohistochemical Expression of Calretinin in Dentigerous Cyst Transforming Into Unicystic Ameloblastoma: A Case Report.

The term "unicystic ameloblastoma" describes cystic lesions that exhibit radiographic, clinical, or gross characteristics of a jaw cyst. However, histologic examination reveals a typical ameloblastomatous epithelium lining the cyst cavity, with or without luminal and/or mural tumor proliferation. Unicystic ameloblastoma is a less prevalent kind of ameloblastoma. Among the odontogenic cysts, neoplastic transformation is highest in odontogenic keratocysts (OKCs) and dentigerous cysts (DCs). Calretinin is considered a specific immunohistochemical marker for neoplastic ameloblastic epithelium and serves as a diagnostic tool for differentiating odontogenic cystic lesions from ameloblastic tumors. This paper illustrates a case of a DC transforming into unicystic ameloblastoma in a 22-year-old male patient using the immunohistochemical expression of calretinin.

Immunohistochemical evaluation of cyclin D1 and p63 in odontogenic keratocyst and unicystic ameloblastoma.

INTRODUCTION: Odontogenic keratocyst (OKC) and unicystic ameloblastoma (UA) are lesions of odontogenic origin. Both lesions are morphologically cysts. However, they are classified as developmental cysts and epithelial odontogenic tumours, respectively. Cyclin D1 (CCD1) dysregulation is associated with oncogenic activity and malignancies, while tumour protein p63 (p63) alterations are associated with tumourigenesis. AIM: To evaluate and compare the protein expression of CCD1 and p63 in sporadic OKC (OKC-sp), syndromic OKC (OKC-sy), and UA. MATERIAL AND METHODS: 45 cases from the Anatomical Pathology Department, Faculty of Dentistry, University of Chile were analysed and divided into groups: OKC-sp (n=15), OKC-sy (n=15) and UA (n=15), the latter categorised into intraluminal and/or luminal (n=7) and mural (n=8). Immunohistochemical staining for CCD1 and p63 proteins was performed from paraffin-embedded sections. Statistical analysis included the Shapiro-Wilk test, one-way ANOVA with Tukey's multiple comparisons, and Spearman's correlation coefficient (p<0.05). RESULTS: There was an involvement mainly in women in the mandibular area, and a high frequency of jaw expansion, especially in the mural UA. P63 protein expression was higher than CCD1 in all cystic lesions, particularly in mural UA (p<0.001). No correlation was found between CCD1 and p63 expression. CONCLUSION: P63 may serve as a valuable marker for evaluating cell proliferative activity in odontogenic cystic lesions, providing insights into the aggressive behaviour of mural UA.

Unicystic ameloblastoma: Clinico-radiological and histopathological correlation with management.

Unicystic ameloblastoma is a distinct entity of ameloblastoma characterized by slow growth and locally aggressive behavior. This retrospective study aimed to assess the efficacy of different treatment modalities of unicystic ameloblastoma, focusing on clinico-radiological and histopathological features. Data from patients diagnosed with unicystic ameloblastoma were retrospectively analyzed. Patients were categorized into luminal and intraluminal (Group A) and mural (Group B) variants based on the Ackermann classification, which has a significant influence on their biological behavior, treatment approaches, and prognosis. Patients in Group A underwent enucleation with chemical cauterization, peripheral ostectomy, and iodoform packing, whereas those in Group B were treated with resection and reconstruction. Post-operatively, the patients were subjected to radiographic assessments via digital orthopantomogram at regular intervals. Because of the rarity of unicystic ameloblastoma, only 17 patients were included in the study (Group A: 9 patients; Group B: 8 patients), with a mean follow-up of 4.9 years (range: 1.4-11.8 years). The primary outcome measure was the absence of recurrence, which indicated treatment success. No patient in either group experienced recurrence within the follow-up period. This study provides evidence supporting the successful treatment of luminal and intraluminal variants of unicystic ameloblastoma in young individuals using a conservative approach. However, the more aggressive mural variant demonstrated favorable outcomes with radical treatment. These findings emphasize the importance of the Ackermann classification in guiding treatment decisions for unicystic ameloblastoma and contribute valuable insights into optimizing therapeutic strategies based on clinico-radiological and histopathological findings.

A case report of a huge unicystic ameloblastoma in the mandible with significant reduction through marsupialization.

INTRODUCTION: Marsupialization is a dependable choice for mandibular unicystic ameloblastoma (UA) management. However, investigations regarding its speed of shrinkage (SS) and reduction rate (RR) are lacking. This case report highlights the treatment of a huge mandibular UA with high SS and RR using marsupialization before secondary surgery. PRESENTATION OF CASE: A 45-year-old male patient presented with severe swelling of the right side of the mandible, resulting in prominent facial asymmetry. Panoramic radiograph revealed a unilocular, radiolucent lesion extending from the mandibular midline to the right ramus. Computed tomography (CT) revealed a large radiolucent lesion that expanded in the buccolingual direction. Incisional biopsy showed that the lesion was UA. After 1.5 years of marsupialization, an SS of 0.183 % per day was reached, leading to an impressive RR of 98.7 %. Treatment was followed by enucleation and peripheral osteotomy. No recurrence was observed at 1 year post-surgery. DISCUSSION: The treatment of mandibular UA remains controversial, ranging from conservative approaches to aggressive interventions. In the current case, marsupialization was highly effective in reducing the volume of the lesion, thereby facilitating a minimally invasive secondary surgery to preserve function. The intact periosteum, which has the potential to differentiate into various cell types, may be associated with the regeneration of new bone after marsupialization. CONCLUSION: Marsupialization remains a successful strategy for managing mandibular UA. Even the huge lesions causing facial deformity can be treated with marsupialization combined with secondary surgery, avoiding the aesthetic and functional disruptions associated with radical treatment.

Evaluation of Paxillin Expression in Odontogenic Cysts and Tumors.

Statement of the Problem: Paxillin (PXN) is one of the proteins involved in cell adhesion. PXN and integrins constitute a key site for the focal adhesion between the cell and extracellular matrix. Several studies have shown that PXN is a factor in tumor formation, progression, invasion, and metastasis. Purpose: This study evaluated PXN expression in four types of odontogenic lesions with different aggressive behaviors. Materials and Method: In this retrospective cross-sectional study, PXN expression was immunohistochemically assessed in 68 paraffin-embedded tissue samples from patients with the confirmed diagnosis of four types of odontogenic lesions, including 14 dentigerous cysts (DC), 20 odontogenic keratocyst (OKC), 16 unicystic ameloblastoma, and 18 solid ameloblastoma. The PXN expression in these samples were scored based on the percentage and intensity of immunoreactivity, and compared among the groups by Chi-square test. Results: The PXN marker was detected in the cytoplasm of tumor cells (unicystic and solid ameloblastoma) and the epithelial layer of cysts (DC and OKC). The intensively stained marker of PXN was observed in 9 cases (64.3%) of the DC, 14 cases (70%) of OKC, 12 cases (75%) of unicystic ameloblastoma, and 13 cases (72.2%) of solid ameloblastoma. However, there was not statistical difference of PXN protein expression between DC and OKC (p Value = 0.51) and unicystic and solid ameloblastoma (p = 0.58), also the same was true for cysts and tumors (p = 0.37). Conclusion: The expression of PXN is not related to the biological behaviors of odontogenic lesions.

Unicystic ameloblastoma appeared as a massive multilocular entity: A case report with long-term follow-up.

INTRODUCTION: Unicystic ameloblastomas are a rare variant of ameloblastomas, which are characterized by slow growth and being relatively locally aggressive, with the main site of origin being the posterior portion of the mandible, it also refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst. PRESENTATION OF CASE: A 27-year-old female patient presented with a chief complaint of extensive mass of mandible along with severe swelling and numbness of right lips and chin. The oral examination revealed a swelling in the molar region of the right mandible with buccal plate expansion. The radiographic and histopathologic features were consistent with the diagnosis of unicystic ameloblastoma. Consequently, the lesion was surgically removed, and no clinical or radiological recurrence was detected during 5 years post-operative follow-up. DISCUSSION: While previous reports of unicystic ameloblastoma in the posterior portion of the jaw showed favorable prognosis lesions appeared as a unilocular entity, this case reports multilocular appearance and aggressive behavior of expansive unicystic ameloblastoma. Furthermore, while some studies linked the unilocular appearance of unicystic ameloblastoma to impacted tooth, our case suggests a possible traumatic link of preexisting lesion into multilocular unicystic ameloblastoma related to impacted tooth. CONCLUSIONS: This case presents a rare multilocular unicystic ameloblastoma appearance, notably with impacted tooth involvement. It also indicates the potential transformation of solid ameloblastoma into unicystic ameloblastom.

Extremely rare maxillary unicystic ameloblastoma causing double vision: First case report in the Middle East.

INTRODUCTION AND IMPORTANCE: Unicystic ameloblastomas are less aggressive than solid (multicystic) variant, unfortunately this subtypes mimics clinically and radiographically more gentle lesions: like odontogenic cysts, so are misdiagnosed unless a histological study is carried out. Moreover, it is clinically silent and normally discovered accidentally. CASE PRESENTATION: 60-year-old male patient, suffering from a pain and swelling located in the left maxillary region; the patient came with double vision and that was the main compliment. Radiographs showed uniocular radiolucent lesion in the left sinus that contained an impacted third molar. Patient asked for minimal aggressive surgical intervention, and a curettage was preformed along with third impacted molar extraction. Final diagnosis was obtained from histological study, the result was intraluminal unicystic ameloblastoma plexiform subtype. Healing went eventually, patient recovered double vision in one month period and six years follow up showed no recurrence. CLINICAL DISCUSSION: Unicystic ameloblastoma is a rare odontogenic lesion, with clinical, radiographic and gross features of jaw cysts. The lesion histologically shows typical ameloblastomatous epithelium lining part of the cyst cavity with or without and/or mural tumor growth. Unicystic ameloblastoma usually presents in posterior mandibular ramus region, while it is rare and atypical in posterior maxillary region. Unicystic ameloblastomas with orbital invasion cases are 4 worldwide and this case reports represents the first case in the Middle East. CONCLUSION: Thorough examination is recommended when unilocular radiolucency of the jaw is detected. Likewise, orbital surgeons are highly advised to take into account the biological behaviors of maxillary odontogenic tumors.

Unicystic ameloblastoma - A case series.

Ameloblastoma is a benign, locally aggressive neoplasm that constitutes about 1-3% of the tumors of the jaw. Wide surgical excision with adequate safe margin is the most common treatment of choice. The study aimed to manage cases with unicystic ameloblastoma while preserving the continuity of the mandible (without resection). This article presents a series of cases ranging from 18 to 40 years old patients of both sexes with unicystic ameloblastoma, especially in the mandible showing more male predilection than female. All the cases presented in this article were treated by enucleation and curettage. None of the patients presented post-operative paresthesia. None of the cases went in for resection. Post-operative recovery was uneventful in all the patients. All the patients were followed up for a period of 3.5-5 years. None of the cases reported recurrence at the date of publication.

Conservative Management of Unicystic Ameloblastoma of Mandible Evolving from Dentigerous Cyst in a Paediatric Patient: A Case Report.

Massive cystic lesions involving a mandible always present a diagnostic and treatment challenge. Unicystic ameloblastoma (UA) is a variant of ameloblastoma encompassing about 6% of ameloblastomas. They represent cystic lesions that reveal clinical and radiographic features of a cyst, but the histopathological features demonstrate a typical ameloblastomatous epithelium lining the cyst. It is a variant of ameloblastoma, usually having clinical and radiographic similarities with dentigerous cysts, hence posing preoperative diagnostic difficulties. Adult treatment protocol cannot be applied to the pediatric population since resection may cause an alteration in craniofacial development leading to functional and esthetical damage, which can directly affect their quality of life. A more conservative approach of enucleating the lesion seems to be a promising treatment modality of UA in the pediatric age group. We present a case of mural variant of UA arising from dentigerous cyst in an 8-year-old male patient.

Unicystic Ameloblastoma Associated with Primary Mandibular Second Molar: A Case Report.

Background: Unicystic ameloblastoma is a rare, benign, locally invasive odontogenic neoplasm of young age that shows clinical, radiographic, or gross features of an odontogenic cyst but histologically shows typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor growth. Aim: To report a case of an asymptomatic unicystic ameloblastoma in a 12-year-old child, along with its management and follow-up. Case description: A 12-year-old boy presented with swelling with respect to the left body of the mandible. The orthopantomogram (OPG) and computed tomography scan revealed a large unilocular radiolucency in the left mandible associated with the primary second mandibular molar. Complete enucleation of the cyst and extraction of the associated primary teeth and underlying permanent teeth were done under general anesthesia. Carnoy's solution was applied in the bone cavity for 3 minutes with cotton applicators. Postoperative healing was uneventful. Prosthetic rehabilitation was done during the follow-up period. Conclusion: Unicystic ameloblastoma is rarely seen in younger children, so a pediatric dentist must be cautious while diagnosing an intraoral swelling. Timely intervention and conservative surgical treatment, along with a proper follow-up, improved the treatment outcome and prevented potential complications in the future. Clinical significance: This report highlights the salient features of unicystic ameloblastoma to be able to accurately diagnose and manage the lesion. How to cite this article: Peter J, Emmatty TB, Jose B, et al. Unicystic Ameloblastoma Associated with Primary Mandibular Second Molar: A Case Report. Int J Clin Pediatr Dent 2023;16(S-3):S335-S338.

Unicystic Ameloblastoma (UA): A Case Series.

Ameloblastomas are true benign tumors of odontogenic epithelial origin mostly seen in the mandible. After odontoma, it is the second most commonly seen odontogenic neoplasm. Ameloblastomas comprise several clinical, radiological, and histological varieties, making them the most significant odontogenic neoplasm. Unicystic ameloblastomas (UAs) refer to those cystic lesions that show clinical, radiographic, or gross features of jaw cysts but on histologic examination, they show a typical ameloblastomatous epithelium lining the cysts' cavities, with or without luminal and/or mural tumor proliferation. UAs are a less encountered variant of ameloblastomas and are believed to be less aggressive. As this tumor shows considerable similarities with dentigerous cysts, both clinically and radiographically the biological behavior of this tumor group was reviewed.

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.

Ameloblastoma uniquístico patrón mural: Reporte de un caso / Unicystic mural ameloblastoma: A case report

El ameloblastoma es un tumor odontogénico agresivo que se clasifica en uniquístico, extraóseo/periférico y metastatizante. Una mujer de 42 años acudió al Servicio de Cirugía Oral y Maxilofacial por aumento de volumen hemifacial izquierdo de 6 meses de evolución. Al examen se observó aumento de volumen de la región parotídea y submandibular izquierda, abombamiento tablas óseas mandibulares y movilidad dental. La tomografía axial computarizada reveló una lesión de aspecto quístico en la región mandibular. Se realizó la biopsia incisional y el tratamiento quirúrgico conservador. El diagnóstico histopatológico fue ameloblastoma uniquístico patrón mural. Luego de seis meses de descompresión, se realizó una nueva biopsia incisional, curetaje óseo y se aplicó solución de Carnoy. Once meses posteriores a la primera intervención, se constató radiográficamente aposición ósea de la lesión. El tratamiento de estos ameloblastomas continúa siendo controversial por lo que cada caso se debe abordar de manera única.

Ameloblastoma is an aggressive odontogenic tumor classified as unicystic, extraosseous / peripheral, and metastasizing. A 42-year-old woman was attended at the Oral and Maxillofacial Surgery Service due to a 6-month facial asymmetry. Clinically, we observed a volume increase of the left parotid and submandibular region, bulging of the mandibular bone tables and dental mobility. Computed Tomography revealed a cystic-like lesion in the mandibular region. An incisional biopsy and conservative surgical treatment were performed. The histopathological diagnosis was unicystic ameloblastoma, mural pattern. After six months of decompression, a new incisional biopsy and bone curettage were performed, and Carnoy's solution was applied. Eleven months after the first intervention, bone apposition was observed in the x-ray. The treatment of these ameloblastomas continues to be controversial, so every case should be approached in a unique manner.

Expression level and proteolytic activity of MMP-2 and MMP-9 in dental follicles, dentigerous cysts, odontogenic keratocysts and unicystic ameloblastomas.

Matrix metalloproteinases (MMPs) are involved in remodeling the extracellular matrix, but also participate in the development of physiopathologic processes. As they are overexpressed in different types of epithelial cancers, it has been suggested that their level expression could explain the different biological behavior between odontogenic cysts and tumors. Here, we compared the expression level and proteolytic activities of MMP-2 and MMP-9 in dental follicles, dentigerous cysts, odontogenic keratocysts and unicystic ameloblastomas. We found similar expression of MMP-2 in all tissues, but a higher activity in cystic and tumor lesions than follicles. On the other hand, MMP-9 expression and activity was greater in cysts and ameloblastoma than in follicles. However, no differences were found in expression or activity of both MMPs between cystic and tumor injuries, suggesting that they could participate in the growth of these lesions, but they cannot define their different biological behavior.

Unicystic ameloblastoma in a 9-year-old child treated with a combination of conservative surgery and orthodontic treatment: A case report.

Unicystic ameloblastoma (UAM) in the pediatric population is a rare clinical entity that has not been well addressed in the literature. Radical approaches affect a growing young patient's physical and psychological development, so conservative approaches are widely used for management in children. This report describes the case of a 9-year-old girl with UAM of the mandible, which also involved the impaction of the first and second premolars. Marsupialization with orthodontic treatment was performed to shrink the lesion and upright the first premolar involved in the tumor. Ten months after marsupialization, the lesion had healed entirely. The combination of conservative surgery and orthodontic treatment effectively shrank the lesion, preserving mandibular growth, preserving the involved first and second premolars, and promoting the eruption of the teeth.

A meta-analysis on the presentation of Unicystic Ameloblastoma in the jaws and the consequences for their treatment.

INTRODUCTION: This meta-analysis provides reliable data on the prevalence of unicystic ameloblastomas (UA's) among solid/multicystic ameloblastomas (SMA's), as well the ratio of their presence in the maxilla and mandible and in the tooth-bearing area versus the posterior regions of the mandible, including the third molar region and ascending ramus. MATERIAL AND METHODS: A systematic review and meta-analysis was performed according to PRISMA guideline using the strategy ((unicystic ameloblastoma) OR (((ameloblastoma) OR (solid ameloblastoma)) OR (multicystic ameloblastoma))) NOT ((((systematic review) OR (literature review)) OR (case report)) OR (Immunohistochemical)). DISCUSSION: The study included 3856 SMA's and 1537 UA's, which amounted to 28.5% UA's. Of the 380 cases of UA from twelve articles that mentioned the involved jaws, 355 were in the mandible and 25 in the maxilla. The preponderance for the mandible is much higher than reports from previous studies of smaller series. Only five articles mentioned the location within the mandible. The vast majority was in the posterior area. CONCLUSION: The consequences for treatment were discussed, with an emphasis on the approach to unicystic lesions in the posterior part of the mandible for which a protocol is suggested.

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.

Dredging: A conservative surgical approach for treatment of large cystic lesions of the jaws.

Background: Treatment modalities of odontogenic cystic lesions of the jaws range from conservative to radical. "Dredging" may be considered the "middle path" between conservative and radical treatment options. It comprises three entities-decompression, followed by repeated scraping of the lesion, and finally, peripheral ostectomy providing margin clearance but without significant morbidity. Aim: To evaluate the outcome of "dredging" in the management of large cystic lesions of the jaws, without major resections and maintaining normal functions. Methodology: This prospective study was conducted on 30 patients. Inclusion criteria were odontogenic cystic lesions at least 2 cm in size either in the proximity of vital structures or in children with developing tooth germs or so large that upon enucleation, can result in pathological fracture. All underwent decompression followed by dredging performed at every 2 to 3 months intervals. Results: Drastic decrease in size of the lesion as measured on Cone Beam Computed Tomography (CBCT) and new bone formation was evident in all patients. The total Reduction Rate (RR) of the cystic lesions was 88.79% in 9.2 months. RR was highest in Calcifying epithelial odontogenic cyst (CEOC) followed by Unicystic Ameloblastoma (UA), Odontogenic Keratocysts (OKC), Dentigerous cyst (DC), and Radicular Cyst (RC) in CBCT. The mean speed of shrinkage was fastest in CEOC, followed by OKC, UA, RC, and DC after dredging. Shrinkage was higher in patients below 20 years of age (P 0.012) and patients with large cystic lesions (P 0.00447). Conclusion: The results suggest that dredging with regular, long-term follow-up can be a successful treatment method for large cystic lesions in young adults. This method includes the benefits of both conservative and radical treatment methods but lacks the disadvantages of either.

Use of Marsupialisation for a Conservative Approach to Huge Cystic Lesions of the Jaws - A Report of three Cases.

Rationale: The management of cystic lesions of the jaws presents a challenge to the surgeon. Marsupialisation, one of the conservative management options, has been used as a single or combined surgical treatment modality for the cystic lesions of the jaws. Patient Concerns: All patients presented with a complaint of a firm swelling of the face with one of the patients presenting with paraesthesia in the affected area. Diagnosis: Clinical and radiographic examination was carried out followed by aspiration cytology. All lesions were provisionally diagnosed with odontogenic cystic lesions. Treatment: Marsupialisation under general anaesthesia was carried out for all patients. Postoperatively, a customised obturator was fabricated. Outcomes: All the patients showed good radiological ossification postoperatively. Take-Away Lessons: The approach to larger cysts remains controversial. The long-term results following the marsupialisation of extensive cysts of this report may help surgeons to opt for a conservative approach to such lesions before aggressive options.