Intraosseous squamous cell carcinoma arising in association with a squamous odontogenic tumour of the mandible

Squamous Cell Carcinoma Arising in a Squamous Odontogenic Tumor of the Maxilla: Case Report and Review of the Literature

Squamous odontogenic tumor (SOT) is an exceedingly rare, benign epithelial odontogenic tumor showing squamous differentiation. It is composed of variably sized and shaped islands of cytologically bland, mature squamous epithelium within a fibrous stroma. In this report, we present a rare transformation of a squamous odontogenic tumor (SOT) of the maxilla into a well-differentiated squamous cell carcinoma (SCC) with involvement of the pterygoid plates. To the best of our knowledge, only two cases of malignant transformation of SOT has been reported in the literature. Herein, we seek to report this extremely rare occurrence to raise awareness of oral and maxillofacial surgeons and pathologists of this unusual, but serious event and perform a literature review of squamous odontogenic tumors.

Exceptional Evolution of a Squamous Odontogenic Tumor in the Jaw: Molecular Approach

A squamous odontogenic tumor (SOT) is an epithelial locally benign neoplasia derived from the periodontium of the jaws. It is considered a lesion of low incidence. Predominantly, it affects the mandible, although both jaw bones may be involved. Here, we discuss the malignant clinical evolution of an SOT lesion in an 80-year-old female patient. The patient exhibited an expansive triangular lesion at the inferior right quadrant. Surgery was performed and an SOT was diagnosed (2019). Two years after, the lesion grew, and the analysis of the biopsy revealed SOT malignization with pleomorphic atypical squamous cells, characteristics of a squamous cell carcinoma (2021). Massive DNA sequencing of formalin-fixed-paraffin-embedded specimens of the initial and relapsed tumors indicated pathogenic mutations in RET and POLE genes in both tumors, loss of ALK, and gain of CDKN1B and MAP2K in the relapse. In addition, the clinical, radiographic, and microscopic features of this neoplasm are discussed and compared with those already published. The case presented contributes to the better understanding of this SOT tumor entity and to indicates its malignant evolution, together with its biological behavior and its histologic, clinical, and radiographic features. Also, it aims to stress the importance of deeper genetic analyses in rare diseases to uncover mutations that help to select a personalized treatment.

Squamous Odontogenic Tumor: Review of the Literature and Report of a New Case

PURPOSE

Squamous odontogenic tumor (SOT) is a rare, benign, locally infiltrative odontogenic tumor of the gnathic bones. It is composed of islands of bland, well-differentiated squamous epithelium of varying shape and size. Because of histologic overlap, SOT has often been overdiagnosed as ameloblastoma and squamous cell carcinoma. It thus becomes important to understand the clinical, radiologic, histopathologic, and treatment characteristics of this tumor.

MATERIALS AND METHODS

Using the PubMed and Google Scholar databases, we searched for reported cases of SOT published in the English-language literature. We were able to retrieve 49 acceptable cases and perform a comprehensive literature review of the intraosseous SOTs, with emphasis on their clinical, radiographic, and pathologic characteristics, as well as treatment strategies. In addition, we present an additional case of SOT affecting the posterior mandible in a 44-year-old female patient.

RESULTS

The tumor in the posterior mandible in our patient was accompanied by acute pain and treated by enucleation. Histopathologic evaluation showed variably sized islands of benign squamous epithelium scattered in a fibrous stroma, consistent with the diagnosis of an SOT. Uneventful healing was noted at the 1-month postoperative appointment. However, the patient was lost to long-term follow-up. Our literature review showed that the average age at the time of diagnosis of SOT is 34.2 years. Men and women are equally affected, and the tumor does not show a predilection for either jaw bone. The most common locations are the anterior maxilla and posterior mandible. Most SOTs are treated conservatively by enucleation or curettage, whereas aggressive or recurrent tumors require radical resection.

CONCLUSIONS

Careful evaluation of the excised specimen, with immunohistochemical investigations, may prove rewarding in differentiating an SOT from other odontogenic neoplasms and thus minimize the patient's chances of undergoing an unnecessary aggressive intervention.

Squamous odontogenic tumor and squamous odontogenic tumor-like proliferations in odontogenic cysts: An updated analysis of 170 cases reported in the literature

PURPOSE

To integrate the available data published on squamous odontogenic tumors (SOT) and squamous odontogenic tumor-like proliferations in odontogenic cysts (SOT-LPOC) into a comprehensive analysis of their clinical/radiologic features.

MATERIALS AND METHODS

An electronic search was undertaken in January 2017. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm a definite diagnosis.

RESULTS

A total of 74 publications reporting 110 SOTs (102 central, 8 peripheral) and 60 SOT-LPOC were included. Compared to SOT-LPOC, SOT showed lower mean age, no preference regarding maxilla or mandible localization, significant association with cortical bone perforation, multilocular radiographic appearance, and mobility of the tooth/teeth associated with the lesion. While 5 recurrent SOT were reported after enucleation, no recurrent SOT-LPOC was found.

CONCLUSIONS

SOT shows a more aggressive biologic behavior than SOT-LPOC, which supports the hypothesis that the two lesions are distinct clinicopathological conditions.

Surgical Management of an Aggressive Multifocal Squamous Odontogenic Tumor

Squamous odontogenic tumor is a rare benign epithelial odontogenic tumor of the jaw. Most are solitary lesions, although rare multifocal lesions have been described. Maxillary lesions have more aggressive behavior. Because of their benign character, these lesions are usually treated using a conservative surgical approach with curettage and surgical enucleation. This report describes the case of a 29-year-old woman with multifocal lesions who was initially treated with conservative surgical therapy. Early recurrence 6 months after surgery prompted more aggressive resection. This case is discussed in the context of current evidence related to the epidemiology, etiology, diagnosis, and therapy of squamous odontogenic tumors.

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.

Multicentric Squamous Odontogenic Tumor: A Case Report and Review of the Literature

Squamous odontogenic tumor (SOT) is a rare benign epithelial odontogenic neoplasm of the jaws. Both intraosseous and peripheral SOTs have been described in the English language literature. While most intraosseous SOTs occur as solitary lesions, a multicentric variant has also been previously described. Although the radiographic and microscopic features are identical for both solitary and multicentric clinical presentations, there are three significant differences between them. More specifically, multicentric SOT presents at an earlier age (third decade of life), has a slightly higher male to female ratio than the solitary type and has a marked predilection for African-Americans. Here we document the eighth reported case of multicentric SOT, which was diagnosed in a 43-year-old African-American male. In addition, we feature focal sebaceous metaplasia, a heretofore unknown microscopic feature of SOT. Clinical, radiological, and histopathological findings are discussed. The differential diagnosis, biological behavior and management modalities for SOT are also addressed.

Odontogenic Cysts and Tumors

This article presents various odontogenic cysts and tumors, including periapical cysts, dentigerous cysts, odontogenic keratocysts, orthokeratinized odontogenic cysts, lateral periodontal cysts, glandular odontogenic cysts, ameloblastomas, clear cell odontogenic carcinomas, adenomatoid odontogenic tumors, calcifying epithelial odontogenic tumors, squamous odontogenic tumors, ameloblastic fibromas, ameloblastic fibro-odontomas, odontomas, calcifying cystic odontogenic tumors, and odontogenic myxomas. The authors provide an overview of these cysts and tumors, with microsopic features, gross features, differential diagnosis, prognosis, and potential diagnostic pitfalls.

Recurrent squamous odontogenic tumor: A case report and review of the literature

Squamous odontogenic tumors (SOTs) are benign, locally infiltrative neoplasms that localize to the periodontium. In total, <50 cases have been reported since the first description of SOTs in 1975. Although the exact etiology of SOTs is unknown, the tumors are considered to derive from the epithelial cell rests of Malassez. SOTs are characterized by radiological and clinical signs and symptoms, including pain with increased sensitivity in the affected area, bone expansion and increased tooth mobility. The present study describes the case of a patient that experienced numerous SOT recurrences and also discusses recommendations for treatment. A locally invasive mandibular SOT was identified in a Caucasian 41-year-old female patient. The treatment involved recommended conservative surgery, including local curettage. In addition, 49 cases published in the literature were reviewed to assess the treatment strategies. The present patient experienced two recurrences of the tumor during the 6-year follow-up period. Ultimately, the vitality of the adjacent teeth was compromised. An apicoectomy with a small amount of resection of the marginal bone was necessary. In >50% of the reported cases of SOT in the literature the adjacent teeth were extracted. The present case of SOT and the associated literature were also discussed. It was concluded that the treatment of choice appears to be a conservative surgical removal, but the successful management of SOTs often requires the removal of the adjacent teeth.

Squamous Odontogenic Tumor: Literature Review Focusing on the Radiographic Features and Differential Diagnosis

Since its first publication in 1975, the squamous odontogenic tumor remains the rarest odontogenic lesion, with around 50 cases in the English-language literature in which the microscopic characteristics are frequently very well demonstrated. However, articles which discuss the radiographic aspects are scarce, especially with emphasis on the differential diagnosis. The present treatise proposes an assessment of jaw lesions with the same radiographic characteristics of the squamous odontogenic tumor to clarify the main findings for dental clinicians during routine diagnosis.

Squamous odontogenic tumor: A case report and review of literature

The squamous odontogenic tumor (SOT) is a rare, benign, locally infiltrative neoplasm of the jaws that appears to originate from the rests of Malassez, gingival surface epithelium or from remnants of the dental lamina. SOT was first described by Pullon et al. (1975). Since then there has been paucity in the number of reported cases, especially in the Indian subcontinent. The tumor is often asymptomatic, although it can present with symptoms of pain and tooth mobility. The characteristic radiographic appearance is that of a triangular-shaped unilocular radiolucency associated with the roots of erupted, vital teeth and has a predilection for the anterior maxilla and the posterior mandible. Histologically, the tumor is characterized by the formation of variably sized nests and cords of uniform, benign-appearing, squamous epithelium with occasional vacuolization and keratinization. We report a case of SOT occurring in a 58-year-old male in the anterior mandible with unusual localization and appearance.

Solid-type primary intraosseous squamous cell carcinoma of the mandible: a case report with histopathological and imaging features

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor arising from odontogenic epithelial remnants within the jawbones. PIOSCC is histopathologically divided into 3 types: solid-type carcinoma, carcinoma derived from a keratocystic odontogenic tumor, and carcinoma derived from an odontogenic cyst. In this article, we report a case of solid-type PIOSCC involving reactive bone formation in the mandible in a 60-year-old female patient together with its histopathological and imaging findings.

Potential pitfalls in diagnostic oral pathology: a review for the general surgical pathologist

Oral developmental, reactive, benign neoplastic and malignant neoplastic conditions, many odontogenic in origin, may not be seen routinely by the general surgical pathologist and therefore may present a diagnostic dilemma. This article describes odontogenic and nonodontogenic conditions with little or no destructive potential along with the more aggressive conditions that resemble them clinically and histologically. The importance of clinical and radiographic correlation as an adjunct to tissue diagnosis is highlighted. Additionally, a brief summary of odontogenesis is presented with attention given to odontogenic embryologic remnants and the developmental and pathologic processes that may arise from them.

Squamous odontogenic tumor: diagnosis and management

The squamous odontogenic tumor (SOT) is a rare, benign, locally infiltrative neoplasm of the jaws that appears to originate from the rests of Malassez. It has been confused with other pathologic entities such as ameloblastomas, carcinomas, and fibromas and clinically may resemble localized periodontal disease. The tumor is often asymptomatic, although it can present with symptoms of pain and tooth mobility. A characteristic radiographic appearance is that of a triangular-shaped or semi-circular lucency associated with the roots of erupted teeth. Histologically, the tumor is characterized by the formation of variably sized nests and cords of uniform, benign-appearing, squamous epithelium with occasional vacuolization and keratinization. Treatment of SOT by conservative surgical excision is normally curative with rare episodes of recurrence reported. Since the clinical presentation of SOT may mimic more common pathologic entities, this case report reinforces the need for careful histologic evaluation of all lesions found in the periodontium.