Ameloblastoma with stromal multinucleated giant cells

Unicystic ameloblastoma with stromal giant cells: A case series of a rare entity

Ameloblastoma is a locally aggressive, benign epithelial odontogenic neoplasm currently classified to include conventional, unicystic, and extraosseous/peripheral subtypes. Giant cells have been reported in various malignancies but rarely in odontogenic neoplasms. To date, only a single case of unicystic ameloblastoma with stromal giant cells has been reported in the literature. We report two new cases with histologic features compatible with unicystic ameloblastoma with stromal giant cells. CD68 immunohistochemical staining of the giant cells supported a histiocytic origin. Further research is needed to better understand the origin and nature of these giant cells.

Clinicopathologic and Molecular Characteristics of Familial Cherubism with Associated Odontogenic Tumorous Proliferations

Cherubism is a rare autosomal dominant condition affecting the jaws and caused by mutations in the gene encoding for the adapter protein SH3BP2 that maps to chromosome 4p16.3. Cherubism is characterized by symmetrically developing bone lesions in the maxilla and mandible. The lesions have been radiographically and histopathologically well-described. Here, we present a family with cherubism with two of its members featuring odontogenic tumorous proliferations in association with persistent central giant cell lesions (CGCL). Specifically, the proband, a 25-year-old male, developed a radiolucent lesion characterized histologically by central odontogenic fibroma-like proliferation in association with a CGCL component, while his mother, at age 57, was diagnosed with primary intraosseous odontogenic carcinoma with areas of benign fibro-osseous lesions. In both patients the lesions occurred in the anterior mandible and presented with clinical enlargement. The son underwent incisional biopsy and did not have additional treatment. His mother underwent extensive mandibulectomy due to widespread tumor. The son has two affected children with classic cherubism while a third child at age 5, had not shown any features of the disease. Mutation analysis of three affected members resulted in the identification of a heterozygous mutation in SH3BP2 (c.1244G>C; p.Arg415Pro). To the best of our knowledge, association of cherubism with odontogenic neoplastic lesions has hitherto not been reported in the literature, thus suggesting a relationship between cherubism with disturbed odontogenesis.

A peripheral giant cell granuloma with extensive osseous metaplasia or a hybrid peripheral giant cell granuloma-peripheral ossifying fibroma: a case report

INTRODUCTION

Peripheral giant cell granuloma and peripheral ossifying fibroma are clinicopathologically distinct gingival lesions. Both are included in clinical differential diagnoses of common benign and reactive gingival epulides in humans. It is often impossible to make a clinical distinction between the two entities, thereby making definitive diagnosis dependent on histopathologic features. While our search of the English literature revealed several reports of peripheral giant cell granuloma with 'bone formation', we were unable to identify any reports of hybrid peripheral ossifying fibroma-peripheral giant cell granulomas.

CASE PRESENTATION

We report a case of a 44-year-old Caucasian man presenting with a three-month history of swelling of his right posterior mandible, related to an area of previous dental implant restoration. A clinical examination revealed modest extraoral facial swelling of his right posterior mandible, while an intraoral examination showed a 45 × 25 × 15 mm sessile, lobular soft tissue mass of the right posterior mandibular gingiva. The mucosal covering of the lesion exhibited focal surface ulceration. A panoramic radiograph showed two implants at the vicinity of the lesion with no other significant findings. An excisional biopsy of the lesion followed by histopathologic examination of the biopsy specimen revealed salient and distinctive features of peripheral giant cell granuloma and of peripheral ossifying fibroma, estimated at near equal proportions. This raises the possibility of a hybrid odontogenic lesion.

CONCLUSION

The presentation of this lesion, with areas of peripheral giant cell granuloma along with a distinct area of extensive osseous formation and stroma reminiscent of a peripheral ossifying fibroma, justifies consideration of this as a possible hybrid lesion. Although the biologic behavior of a combined lesion is not anticipated to deviate significantly from that of either of the single entities, this case resurrects an enduring debate as to whether peripheral giant cell granuloma and peripheral ossifying fibroma are simply parts of a disease spectrum, or whether some of these lesions represent true hybrid lesions. It is therefore recommended that more cases with histopathologic features similar to the lesion in our case be reported in the literature to further elucidate the histogenesis of these lesions.

So-called hybrid central odontogenic fibroma/central giant cell lesion of the jaws. A report on seven additional cases, including an example in a patient with cherubism, and hypotheses on the pathogenesis

BACKGROUND

Central odontogenic fibroma (COF) is characterized by poor to cellular fibroblastic proliferation and a variable odontogenic epithelial (OE) component. Central giant cell lesions (CGCL) are osteolytic fibroblastic proliferations characterized by osteoclast-like multinucleated giant cells (MGC). Rare examples of hybrid COF/CGCL have been described. Two pathogenetic theories prevail based on clinicopathologic characteristics. One regards the CGCL component as reactive to the COF, while the other regards the CGCL as inductive of a COF-like proliferation. The possibility of colliding tumors seems unlikely.

METHODS AND MATERIALS

Seven patients with hCOF/CGCL, among them one with cherubism, were studied. Immunohistochemistry for cytokeratin 19 was applied to better appreciate the epithelial component.

RESULTS

Six patients were males and one female and their age ranged from 15 to 73 years old. All lesions occurred in the premolars and molars of the mandible and presented as radiolucencies with primarily well-delineated borders. All patients underwent surgical excision and recurrences have not been reported to this date in 6 out of 7 patients (mean follow-up 60.6+/-36.25 months). The COF component predominated in 3 cases and the CGCL component in 3. Zones of collagen fibers featuring a whorling pattern and containing multiple nests of OE were present. In four cases there were hyalinized deposits in OE, while some foci of MGC contained few OE.

CONCLUSIONS

Gender predilection in our series is in contrast with previously published reports. However, when all previously reported cases are reviewed there is still female predilection. The predominant site, as previously reported, is the tooth-bearing areas of the posterior mandible. This is the first report of hCOF/CGCL in cherubism. The pathogenesis of hCOF/CGCG remains obscure and molecular interactions would be of interest to be investigated.

The spectrum of giant cells in tumours of the salivary glands: an analysis of 11 cases

In view of the different terminology for salivary gland tumours with giant cells, eleven cases were analysed by histopathology and immunocytochemistry. Four cases (three pleomorphic adenomas, one carcinosarcoma in a pleomorphic adenoma) were classified as having a foreign-body giant cell reaction, and five cases (two mucoepidermoid carcinomas, one acinic cell carcinoma, two carcinomas in pleomorphic adenomas) as having a sarcomatoid osteoclast-like giant cell reaction. In two further cases a giant cell tumour and a giant cell granuloma were associated with carcinomas in pleomorphic adenomas. All giant cells showed characteristic expression of CD68 as a typical marker for histiocytes and macrophages with their origin in mononuclear haematopoetic stem cells. There was no evidence for an epithelial origin of the giant cells because all those examined had a negative reaction to cytokeratin. Foreign-body cells were characterized by cytoplasmic vacuoles and irregularly dispersed nuclei. They showed a focally circumscribed reaction mostly outside the connective tissue pseudocapsule of the tumours. The sarcomatoid osteoclast-like giant cell reactions in carcinomas were distinctly intermingled with the carcinomatous patterns. In contrast, the associated osteoclast-like giant cell tumour was distinctly separate from the salivary gland tumour tissue and was composed of numerous larger osteoclast-like giant cells with a greater number of nuclei (more than 20); these giant cells were uniformly distributed throughout the tumour tissue. The giant cell granuloma was also separate from the carcinoma and was composed of nests of smaller, more irregularly distributed giant cells.