Squamous Odontogenic Tumor in the Posterior Region of Maxilla.

Squamous odontogenic tumor (SOT) is a rare benign but locally infiltrative tumor often misdiagnosed as other entities, such as ameloblastoma and squamous cell carcinoma, due to overlapping morphological findings. We document here the clinicopathological and imaging findings of an aggressive intraosseous SOT in the posterior left region of the maxilla in a 25-year-old male patient. On intraoral examination, the tumor extended from the region of the left lateral incisor to the upper left premolar and was covered by reddish mucosa, with discrete areas of ulceration. Imaging exams revealed an osteolytic lesion causing thinning, erosion, and buccal and lingual cortical plate perforation associated with an impacted canine. Microscopically, the tumor showed a proliferation of islands of well-differentiated squamous epithelium in a variably collagenized background. The peripheral cells of the islands were flat or slightly cuboidal and did not exhibit nuclei with peripheral palisade and reverse polarization. The diagnosis of SOT was rendered. The patient underwent surgical resection and has been under clinical follow-up for approximately 12 months with no signs of recurrence. A careful morphological evaluation is essential to avoid misdiagnosis and ensure a satisfactory treatment approach.

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.

The first parent-child diagnosis of a multifocal squamous odontogenic tumor: A case report.

Squamous odontogenic tumors (SOT) are rare, benign, odontogenic neoplasms of the jaws. The sporadically reported cases with multifocal SOTs seem to have a marked predilection for younger African American patients. In this case report a 14-year-old Caucasian male presented with swelling of the vestibular alveolar process, slight tooth divergence, and mobility. A multifocal squamous odontogenic tumor was diagnosed and subsequently treated twice with surgical enucleation. Two and a half years earlier his mother was diagnosed and treated for a similar multifocal SOT. Next-Generation-Sequencing targeted resequencing mutational analysis of the maternal surgical specimens was performed. No potential causal mutation could be identified. Postoperative follow-up of the patient showed no recurrence of the SOT after 2 years. This case report substantiates the possibility of a familial relationship in (multifocal) SOT, possibly changing current ideas concerning the etiology and treatment of these neoplasms.

Diagnosis and Treatment of an Odontogenic Epithelial Tumor in a Dog With Features of Squamous Odontogenic Tumor.

A 9-year-old standard poodle presented for a comprehensive oral health assessment and treatment, at which time a left rostral mandibular swelling was recognized. The mass was biopsied and eventually excised by a left rostral mandibulectomy en bloc resection. Histopathology supported the diagnosis of a benign, intraosseous, epithelial tumor that was otherwise unclassified. The clinical, radiological, and histological features of this case are similar to those reported for squamous odontogenic tumor (SOT) in humans. This case study relays the diagnosis, treatment, and follow-up of the first SOT-like tumor in a dog.

Review of 109 cases of primary malignant orofacial lesions seen at a Nigerian Tertiary Hospital.

BACKGROUND: Orofacial malignancy is a growing health issue common in developing regions of the world. Presentation patterns are myriad with geographic variations. Advanced stage owing to late presentation constitutes a significant public health burden. The site and type of the lesions are valuable in diagnosis and patient management. AIM: This study aims to review cases of primary orofacial malignancies at the OAUTHC Dental Hospital. OBJECTIVES: The objective of the study was to determine the prevalence of histologically diagnosed orofacial malignancies, the relative frequencies, types and site of distribution. MATERIALS AND METHODS: Records of patients with orofacial malignancies at the OAUTHC, Dental Hospital over a period of 10 years (January 2008-December 2017) were reviewed, demographic data (age, gender and site), history of tobacco use were retrieved and entered into a pro forma. The data obtained were analysed with STATA 11. Statistical significance was set at P < 0.05. RESULTS: Of 375, 109 cases of neoplasms seen were primary malignant tumours, with prevalence rate of 29.1%. There were 71 (65.1%) males and 38 (34.9%) females (male:female ratio of 1.87:1), mean age (48.7 ± 19.3 years) and range (4-94 years). Affected sites were mandible (41, 37.6%), maxilla (39, 35.8%), palate (17, 15.6%) and others. Lesions were mainly squamous cell carcinomas (SCC: 46, 42.2%), salivary gland adenocarcinomas (SGAs, 25, 22.9%) including 8 (32%) cases of adenoid cystic carcinoma (ACC). Others were odontogenic carcinoma (18, 16.5%) and lymphoma (8, 7.3%). Most specimen analysed were hard tissues (n = 63, 57.8%). Thirty-four (73.9%) cases of SCC and 66 (60.6%) cases of primary malignancies were in the 5th-9th decades of life. This was statistically significant at P = 0.000. CONCLUSION: SCC was more prevalent than salivary and odontogenic carcinomas. ACC and mucoepidermoid carcinoma were two most common SGAs. Metastatic tumours to the jaws are rare.

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.

A squamous odontogenic tumor following an orthodontic micro-screw: A rare case report and review of the literature.

We reported a very rare case of squamous odontogenic tumor(SOT) in a 23-year-old female. The tumor arose after an implanting operation of an orthodontic micro-screw, and was definitely diagnosed by the histopathological examination. Based on the case report and a review of the literature, we discussed about the general features, differential diagnosis and pathogenesis of SOT.

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.

Clear cell odontogenic carcinoma, diagnostic difficulties. A case report.

INTRODUCTION: Clear cell odontogenic carcinoma (COCC) is a rare tumor described by Hansen et al. in 1985. The clinical and radiological manifestations are multiple and the diagnosis is histological. OBSERVATION: A 64-year-old patient consulted us for a right mandibular osteolytic lesion associated to a homolateral labial hypoesthesia. A biopsy was performed under local anesthesia. Histology was consistent with a metastatic lesion of clear kidney cell carcinoma, COCC, or odontogenic squamous tumor. Additional tests eliminated a metastatic lesion. A wide excision of the lesion by hemi-mandibulectomy associated with lymph node dissection and reconstruction by a fibula osteoseptocutaneous flap was performed. Presence of a fission of the EWSR1 gene on the histological examination of the surgical specimen made the diagnosis of COCC. DISCUSSION: Our observation illustrates the difficulty of diagnosing COCC. The new contribution of the cytogenetic techniques such as FISH-type techniques makes possible the improvement of the diagnosis.

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.

Prognostic Factors of Primary Intraosseous Squamous Cell Carcinoma (PIOSCC): A Retrospective Review.

OBJECTIVES: To delineate clinical and pathological features and determine the prognostic factors of primary intraosseous squamous cell carcinoma (PIOSCC). MATERIALS AND METHODS: Patients diagnosed with PIOSCC, attending the department of oral and maxillofacial surgery, Nanjing stomatological hospital between 2005 and 2015, were identified and retrospectively reviewed for clinical and pathological characteristics. Therapeutic modalities were measured and related follow-up data recorded, in order to determine prognostic factors of PIOSSC. RESULTS: A total of 77 patients with PIOSCC were included in the study. Mean age at diagnosis was 58.8 years, (range, 37-81 years). Of the 77 patients, there were 58 men and 19 women. The most common location of disease was the mandible (71.42%), particularly the posterior mandible. The common presenting symptoms included jaw swelling (79.2%) and ulceration (42.65%). The estimated 2-year and 5-year overall survival were 68.9% and 38.8%, respectively. Univariate analysis identified the following as negative prognostic factors: histological grade, N classification, nodal status and treatment modalities. However, multivariate analysis determined positive nodal status, high histological grade and advanced N classification as the independent significant prognostic factors. CONCLUSION: Our results demonstrate several clinical and pathological features of PIOSCC and identify important prognostic factors associated with overall survival in PIOSCC. These prognostic factors include nodal status, histological grade, N classification, and treatment modalities, all of which are important for patient counseling and may be useful for the development of new treatment approaches.

The large intracellular loop of ptch1 mediates the non-canonical Hedgehog pathway through cyclin B1 in nevoid basal cell carcinoma syndrome.

Mutations in the transmembrane receptor patched homolog 1 (Homo sapiens) (ptch1) are responsible for nevoid basal cell carcinoma syndrome (NBCCS), an autosomal dominant disorder that causes developmental abnormalities and predisposes the affected individuals to cancer. Many of these mutations, including mutations in the C-terminus of the large intracellular loop (ICL) of ptch1 (p.C727VfsX745 and p.S733IfsX736), result in the premature truncation of the protein. The ptch1­C727VfsX745 and ptch1-S733IfsX736 mutations have been identified in patients with NBCCS­associated keratocystic odontogenic tumors (KCOTs). In the present study, we found that the molecular mechanisms regulated by the non-canonical Hedgehog (Hh) signaling pathway through cyclin B1 are involved in the pathogenesis of NBCCS-associated KCOTs. In contrast to wild-type ptch1, ptch1-C727VfsX745 and ptch1­S733IfsX736 clearly exhibited reduced binding to cyclin B1. Moreover, the cells expressing these two mutations demonstrated an increase in cell cycle progression and these two mutation constructs failed to inhibit cell proliferation. In addition, the mutants enhanced the activity of glioma-associated oncogene family zinc finger 1 (GLI1), a downstream reporter of Hh signaling. Thus, our data suggest that the non-canonical Hh pathway mediated through ptch1 and cyclin B1 is involved in the pathogenesis of NBCCS-associated KCOTs. The C-terminus of ICL in ptch1 may also be a potential therapeutic target in the treatment of this disease.

Intraosseous pseudocarcinomatous hyperplasia associated with chronic osteomyelitis of the mandible: report of two cases.

Pseudocarcinomatous hyperplasia (PH) is a marked proliferation of benign squamous epithelium lacking cytologic atypia and pleomorphism in response to chronic stimuli, such as inflammation, infection, irradiation, or an underlying neoplastic reaction. Intraosseous PH is a rare complication of chronic osteomyelitis and mimics squamous cell carcinoma and other squamous neoplasms. This report describes 2 cases of intraosseous PH arising in the mandible.

Metallothionein immunoexpression in selected benign epithelial odontogenic tumors.

BACKGROUND: Odontogenic tumors exhibited variable biologica behaviors. Metallothionein (MT) is correlated with the cellular homeostasis of essential metals, cellular differentiation, and proliferation. The core goals of this study are (i) to report and to compare MT expression among benign epithelial odontogenic tumors; (ii) to correlate MT with cellular proliferation index; and (iii) to evaluate the influence of the inflammatory infiltrate on MT expression. MATERIALS AND METHODS: Ten cases of solid ameloblastomas (SABs), 4 squamous odontogenic tumors (SOTs), 5 adenomatoid odontogenic tumors (AOTs), and 3 calcifying epithelial odontogenic tumors (CEOTs) were subjected to immunohistochemical to anti-MT, anti-Ki-67, and anti-PCNA. Statistical analysis was performed using BioEstat(®) 4.0. RESULTS: Metallothionein staining was found to be the highest in the SABs (93.1%), followed by SOTs (52.9%), AOTs (38.4%), and CEOTs (0%). MT staining exhibited statistically significant differences between the SABs and the SOTs (P = 0.0047) and the AOTs (P = 0.0022). A weak-to-strong positive correlation between IMT and IK or IP was observed in SABs and SOTs, whereas a strong negative correlation was observed in AOTs. No differences in IMT, IK, and IP were observed between inflammation groups A and B. CONCLUSIONS: The increased MT expression observed in the SABs might be correlated with clinical behavior (local invasiveness and high rate of recurrence). In the SABs and SOTs, MT plays a role in the stimulation of cellular proliferation. In contrast, MT can inhibit cellular proliferation in the AOT. The IMT, IK, and IP are not affected by inflammation.

The diagnostic and surgical management of a multifocal calcifiyng epithelial odontogenic tumor in the mandible and maxilla associated with a squamous odontogenic tumor: first reported case in the literature.

The calcifiyng epithelial odontogenic tumor (CEOT) and the squamous odontogenic tumor (SOT) are rare and benign odontogenic tumors that affect the jaw. This article describes the diagnostic and surgical management of a multifocal CEOT in the mandible and maxilla associated with an SOT. This case is the first to demonstrate that there may be a multifocal variant of CEOT associated with an SOT that has not been previously recognized. Clinical, radiographic, and histologic signs are reported. Treatment modality, oral rehabilitation, and long-term follow-up are shown. Because of the rarity of this kind of simultaneous pathologic association, it is of paramount, and indeed obvious, importance to prospective reviewers that published reports are produced meticulously, including all clinically, radiographically, and histologically relevant data.

A clinicopathological study of malignant odontogenic tumours.

AIMS: Malignant odontogenic tumours (MOTs) are rare neoplasms occurring primarily within the jaw. The objective of this study was to determine the incidence, demographics and clinicopathological features of the MOTs from two institutions. METHODS AND RESULTS: The records of the Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand and the Department of Oncology and Diagnostic Sciences, Dental School, University of Maryland, Baltimore, USA were searched from 1991 to 2010; we identified 17 cases of previously diagnosed MOTs. All cases were reviewed independently of the previous diagnosis by two blinded oral pathologists and reclassified based on the 2005 World Health Organization classification of head and neck tumours. In this study we describe in detail these 17 cases which presented with an average age of 50.29 years and a male to female ratio of 2.4:1. These cases included five ameloblastic carcinomas, four atypical ameloblastomas, three primary intraosseous squamous cell carcinomas, three intraosseous mucoepidermoid carcinomas and two clear cell odontogenic carcinomas. All cases were treated by surgical resection and one patient with ameloblastic carcinoma received postoperative radiotherapy. CONCLUSIONS: Malignant odontogenic tumours are considered rare central odontogenic lesions. Awareness of their existence, rapid diagnosis and successful treatment using surgery, radiation and/or chemotherapy is critical to patient survival.