Rare giant granular cell ameloblastoma: a case report and an immunohistochemical study

Unusual Variant of Unicystic Ameloblastoma with CEOT-Like Areas: A Rare Case Report with Review of Literature

Ameloblastoma is an epithelial odontogenic neoplasm with clinical and histological diversity. They are locally invasive tumors with 3 clinical variants such as solid, unicystic, and peripheral ameloblastomas, and the unicystic variant constitutes only 13%. Histologically, it shows diverse microscopic patterns that may occur isolated or in combination with other patterns. The granular cell variant accounts for 3.5% of all ameloblastoma cases. The eosinophilic granules seen in the cytoplasm of the tumor are thought to be lysosomes and presumably contribute to the pathogenesis of the tumor. Although such a phenomenon is rare in unicystic ameloblastoma, granular cell differentiation in solid multicystic ameloblastoma is a well-established phenomenon. In this paper, we present a unique case of unicystic ameloblastoma with granular cell differentiation with a brief review.

Unusual Variant of Unicystic Ameloblastoma with CEOT-Like Areas: A Rare Case Report with Review of Literature

Ameloblastoma is an epithelial odontogenic neoplasm with clinical and histological diversity. They are locally invasive tumors with 3 clinical variants such as solid, unicystic, and peripheral ameloblastomas, and the unicystic variant constitutes only 13%. Histologically, it shows diverse microscopic patterns that may occur isolated or in combination with other patterns. The granular cell variant accounts for 3.5% of all ameloblastoma cases. The eosinophilic granules seen in the cytoplasm of the tumor are thought to be lysosomes and presumably contribute to the pathogenesis of the tumor. Although such a phenomenon is rare in unicystic ameloblastoma, granular cell differentiation in solid multicystic ameloblastoma is a well-established phenomenon. In this paper, we present a unique case of unicystic ameloblastoma with granular cell differentiation with a brief review.

Radiographic estimation of the growth rate of initially underdiagnosed ameloblastomas

BACKGROUND

To evaluate the specific growth rate (SGR) of ameloblastoma.

MATERIAL AND METHODS

cases of ameloblastoma initially underdiagnosed (e.g. cases overlooked or diagnosed as reactive lesions) which had adequate radiographic documentation to evaluate their progression were retrospectively selected. Two panoramic radiographs were analyzed to determine the specific growth rate (SGR) of each tumor, defined as the logarithm of the ratio of final tumor area (when the diagnosis of ameloblastoma was made) to the initial tumor area (when the lesion was underdiagnosed), divided by the time interval between the radiographic images. The tumor area was measured using the software ImageJ.

RESULTS

Twelve patients with mandibular ameloblastomas were selected, including 5 males and 7 females, with a mean age of 24.9 years (range: 14-61 years). In four cases, the lesion was associated with the crown of an impacted third molar. In three cases, it was initially diagnosed as a periapical lesion. Three cases were extrafollicular and were not noticed in the initial radiographs. Two cases were initially diagnosed as ameloblastoma, but the surgery was delayed for personal reasons. The mean interval of time between the two radiographic images was 4.3 years (range: 0.4-9 years). Based on our analysis, ameloblastoma grows in average 40.4% per year (range: 14.9-88.7%).

CONCLUSIONS

Ameloblastoma is a progressively growing tumor, but its growth rate seems to be smaller than initially reported in the literature. Better understanding the radiographic progression of ameloblastoma might improve its early diagnosis, management, and prognosis.

Ameloblastoma with distinctive granular cell pattern: an 8 case study

Ameloblastoma with granular cell pattern (AGC) is classified as an unusual histological subtype of solid/multicystic ameloblastoma, characterized by granular changes in stellate-like cells located within the inner portion of the epithelial follicles. Studies have revealed that lysosomal overload causes cytoplasmic granularity; however, the mechanism involved remains poorly understood. Here we report on eight cases of granular cell ameloblastoma, in the posterior region of the mandible. The age of the patients included in this case series ranged from 35 -64 years old and 87.5% of cases occurred in non-Caucasians, with a slight gender predilection for men (62.5%). There was no evidence of recurrence, and the majority of the cases were treated with surgical resection (87.5%). All tumors displayed histopathological features consistent with the diagnosis of ameloblastoma with granular cell pattern.

Granular cell ameloblastoma

A 42-year-female patient presented with a swelling on the left side of the face for the past 10 years. The radiograph shows multilocular radiolucency with evidence of root resorption. Histopathology reveals fibrous connective tissue exhibiting numerous odontogenic epithelial islands with peripheral tall columnar cells showing a reversal of polarity. The center of the island shows stellate reticulum like cells. The connective tissue also shows the presence of extensive coarse granular eosinophilic cells distributed throughout the section.

Mandible ameloblastoma with lung metastasis: a rare case report

BACKGROUND

The ameloblastoma is the most common odontogenic epithelial tumor, which belong to benign neoplasms that present a painless course, and usually occur in the oromaxillo-facial region. Although the histopathological manifestation of ameloblastoma is benign, it has unique biological behavior, for example local invasion and recurrence repeatedly. A few case of ameloblastoma was locally aggressive growth, and rarely metastasis to other tissue, for example the lungs, lymph nodes, and spine.

CASE REPORT

A 64-year-old Chinese man, diagnosed with metastatic ameloblastoma, was treated with palliative chemotherapy consisting of cyclophosphamide, doxorubicin, and cisplatin for six cycles, and radiotherapy for 50 Gy after the last cycle chemotherapy. During the surveillance CT scan after the therapy, the tissues of the tumor were nearly complete response.

CONCLUSION

The purpose of this study was to report a case of a patient with a right mandible ameloblastoma that recurred repeatedly and metastasized into bilateral lung. After the chemotherapy and radiotherapy, the tissues of the tumor were nearly complete response. This case is interesting because it investigated the diagnosis and treatment of the malignancy ameloblastoma, as this may help diagnose and treatment for clinician to the metastatic ameloblastoma.

Establishing the natural history and growth rate of ameloblastoma with implications for management: systematic review and meta-analysis

Background

Ameloblastoma is the second most common odontogenic tumor, known to be slow-growing, persistent, and locally aggressive. Recent data suggests that ameloblastoma is best treated with wide resection and adequate margins. Following primary excision, bony reconstruction is often necessary for a functional and aesthetically satisfactory outcome, making early diagnosis paramount. Despite earlier diagnosis potentially limiting the extent of resection and reconstruction, an understanding of the growth rate and natural history of ameloblastoma has been notably lacking from the literature.

Method

A systematic review of the literature was conducted by reviewing relevant articles from PubMed and Web of Science databases. Each article’s level of evidence was formally appraised according to the Centre of Evidence Based Medicine (CEBM), with data from each utilized in a meta-analysis of growth rates for ameloblastoma.

Results

Literature regarding the natural history of ameloblastoma is limited since the tumor is immediately acted upon at its initial detection, unless the patient voluntarily refuses a surgical intervention. From the limited data, it is derived that the highest estimated growth rate is associated with solid, multicystic type and the lowest rate with peripheral ameloblastomas. After meta-analysis, the calculated mean specific grow rate is 87.84% per year.

Conclusion

The growth rate of ameloblastoma has been demonstrated, offering prognostic and management information, particularly in cases where a delay in management is envisaged.

Massive granular cell ameloblastoma with dural extension and atypical morphology

Ameloblastomas are rare histologically benign, locally aggressive tumors arising from the oral ectoderm that occasionally reach a gigantic size. Giant ameloblastomas are a rarity these days with the advent of panoramic radiography in routine dental practice. Furthermore, the granular cell variant is an uncommon histological subtype of ameloblastoma where the central stellate reticulum like cells in tumor follicles is replaced by granular cells. Although granular cell ameloblastoma (GCA) is considered to be a destructive tumor with a high recurrence rate, the significance of granular cells in predicting its biologic behavior is debatable. However, we present a rare case of giant GCA of remarkable histomorphology showing extensive craniofacial involvement and dural extension that rendered a good prognosis following treatment.

Unusual histological patterns and hyaline ring granulomas in a unicystic ameloblastoma

BACKGROUND

Unicystic ameloblastoma (UA) is a distinct variant of ameloblastoma displaying a large cystic cavity lining by ameloblastomatous epithelium and can present a wide variety of histologic patterns.

CASE REPORT

We herein reported an unusual UA occurring in the mandible of a 23-year-old male patient who exhibited luminal, intraluminal and mural patterns, as well as acanthomatous, basal cells and granular cell variants. In addition, hyaline ring granulomas, an extraordinary finding in ameloblastoma, were found. The nature of several microscopic variants in this tumor and the possible significance of their presence have also been discussed.

CONCLUSIONS

We believe this to be the first case reported in which a UA displayed multiplicity of histopathological patterns in a single lesion.