An unusual clinical and histopathologic presentation of a maxillofacial ameloblastoma: a literature review and case report.

The objectives of this article are to describe an unusual clinical and histopathologic presentation of an ameloblastoma affecting the right maxilla, maxillary sinus, and nasal cavity and to discuss the difficulty of establishing a clinical classification based on the most recent edition of Head and Neck Tumours in the WHO Classification of Tumours series (2022). A 74-year-old man presented with a 6 × 6-cm expansile, ulcerated mass on the right lateral palate. A clinical diagnosis of squamous cell carcinoma was rendered. A biopsy was performed, and the specimen showed multiple histologic patterns of ameloblastoma inconclusive of odontogenic or sinonasal origin. Cone beam computed tomographic imaging demonstrated a well-defined unilocular mass in the right maxilla extending up to the nasal cavity. A surgical resection was performed and confirmed the diagnosis of maxillary ameloblastoma with extension into the nasal cavity. This dilemma in delayed diagnosis led to a literature search for similar maxillary ameloblastoma cases with extension into vital structures. In 45 cases previously reported in the literature, the median age of patients with maxillary ameloblastoma was 50 years, and there was extensive involvement of adjacent vital structures. The nasal cavity/sinonasal region (24/45), orbit/orbital floor (12/45), multiple fossae (5/45), and base of the skull (4/45) were the most common extensions of maxillary ameloblastoma. Fifteen patients had lesions with multiple extensions, and 1 patient showed lung metastasis. The most common histologic presentation was the follicular pattern, followed by the plexiform pattern or mixed follicular and plexiform patterns. Surgical interventions were performed on most patients, with the majority undergoing maxillectomy. Differentiating primary sinonasal ameloblastoma from gnathic ameloblastoma with sinonasal extension is challenging, and this article discusses subtle radiographic criteria and symptoms that aid in the distinction of both types. The authors suggest that variants of maxillary ameloblastoma with extensive involvement of the sinonasal region, orbit, or base of the skull be classified with a clinical diagnosis of maxillofacial ameloblastoma, regardless of the tumor origin.

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.

[Komplexes Odontom im Unterkieferfrontzahnbereich bei einer 16-jährigen Patientin - Diagnostik, Therapie und Nachsorge].

Odontome gelten zusammen mit den Amelo- blastomen als die häufigsten odontogenen Tumoren. Sie entstehen während der embryo- nalen Zahnkeimentwicklung durch fehlerhaft differenziertes Keimgewebe und werden daher auch als Hamartome bezeichnet. Somit sind sie also strenggenommen keine klassischen Neoplasien.

Osteosarcoma with widespread metastasis in a 1-year-old crossbred rabbit.

A 14-month-old female spayed, small crossbred rabbit presented for assessment of a small, hard subcutaneous nodule in the right axilla. Serum biochemistry showed markedly increased serum ALP activity. A whole-body CT revealed an aggressive, monostotic osteolytic, and productive lesion within the left alveolar process of the maxilla, with erosion of the alveolar bone and secondary premolar depression. Innumerable metastatic osseous masses were present throughout the body, including cerebral, pulmonary, hepatic, subcutaneous, and skeletal muscular metastases. Postmortem findings confirmed widespread, metastatic osteosarcoma, with the primary lesion within the left maxilla.

Maxillary Cystic Ameloblastic Fibroma in a Dalmatian Mix.

A 6-month-old intact male Dalmatian mix puppy was presented for the evaluation of left maxillary swelling due to a suspected cyst and an unerupted left maxillary canine tooth. Removal of the unerupted left maxillary canine tooth (204) and enucleation of the cyst was performed, followed by histological analysis, which identified the maxillary swelling to be a cystic ameloblastic fibroma. Ameloblastic fibromas are rare in companion animals, and to the best of the authors' knowledge, this is the first cystic variant reported in dogs. The clinical, radiographic, cone beam computed tomography, and histological findings of this case are discussed and compared with the findings of previously documented human and domestic animal cases.

Chondromyxoid fibroma affecting the maxilla in a 1-year-old child: Immunohistochemical analysis and literature review.

Chondromyxoid fibroma (CMF) is a benign chondroid/myxoid matrix-producing tumor that often develops in the long bones of young adults. CMF is rarely reported in the craniofacial skeleton, with most cases presenting with bone erosion or destruction, which may lead to a misdiagnosis. To date, approximately 129 cases of CMF in the craniofacial region have been reported, with only three cases in patients aged less than 1 year. Of these 129 cases, only 34 affected the jaws. A 1-year-old boy presented with a mass in the left anterior maxilla, extending and compressing the ipsilateral nasal cavity. After surgical excision of the lesion, microscopy revealed spindle-to-stellate tumor cells surrounded by a predominant myxoid stroma containing focal slit-like vascular channels and hemorrhagic areas. Immunohistochemistry showed positivity for vimentin, CD10, and α-SMA (focal). The Ki-67 labeling index was 6%. CFM should be included in the differential diagnosis when assessing maxillary tumors in pediatric patients.

Jaw osteosarcoma and pregnancy: a rare coexistence

Osteosarcoma of the jaw represents less than 1% of all head and neck malignancies. This malignancy in pregnant women occurs in one per 1000 deliveries. We report a case of a 29-year-old woman, in the 33rd week of gestation, who presented with an expansive tumor destroying the maxillary alveolar bone, histologically composed of pleomorphic, round, spindle, or epithelioid cells and osteoid/chondroid matrix. Upon final diagnosis of osteosarcoma, the lesion was excised. To the best of our knowledge, only 10 cases of jaw osteosarcoma in pregnant women have been reported to date in the English language literature. The use of ancillary examinations, malignancy diagnosis, and cancer treatment can be challenging during pregnancy. Knowledge about jaw osteosarcoma in pregnancy can increase healthcare providers' awareness, avoid delays and misdiagnosis and potentially improve maternal and neonatal outcomes.

Long-term Effect of Individualized Titanium Mesh in Orbital Floor Reconstruction After Maxillectomy.

OBJECTIVE: The aim of this study was to determine the clinical outcomes and long-term stability of individualized titanium mesh combined with free flap for orbital floor reconstruction after maxillectomy and to identify the risk factors for titanium mesh exposure. MATERIAL AND METHODS: The data of 66 patients who underwent maxillectomy and orbital floor defect reconstruction by individualized titanium mesh in Peking University School and Hospital of Stomatology between 2011 and 2019 were retrospectively reviewed. Postoperative ophthalmic function and success of aesthetic restoration were assessed. Titanium mesh exposure was recorded and the risk factors were identified. RESULTS: Mean follow-up was for 24.8 months (range, 6-92 months). Ophthalmic function was successfully restored in 63/66 patients. Aesthetic restoration was not considered satisfactory by 10 patients. Titanium mesh exposure occurred in six patients (exposure rate, 9.1%). Preoperative radiotherapy was identified as an independent risk factor for mesh exposure (OR = 28.8, P = 0.006). Previous surgery, postoperative radiotherapy, pathological type of the primary lesion, the type of tissue flap applied, and the use of intraoperative navigation were not significant risk factors. Six patients with titanium mesh exposure underwent second surgery, but mesh exposure recurred in two patients due to insufficient soft tissue coverage. CONCLUSION: Individualized titanium mesh with free flap can effectively restore maxilla-orbital defects. Preoperative radiotherapy is an independent predictor of postoperative titanium mesh exposure. Adequate soft tissue coverage of the mesh may reduce the risk of mesh exposure. LEVEL OF EVIDENCE: 4 (case-control study) Laryngoscope, 131:2231-2237, 2021.

Clear Cell Odontogenic Carcinoma: First Report of Novel EWSR1-CREM Fusion Gene in Case of Long-Term Misdiagnosis.

Clear Cell odontogenic Carcinomas (CCOC) are rare, aggressive malignant odontogenic tumours which are often misdiagnosed as benign odontogenic tumours due to the non-specific histologic appearance, and benign early clinical presentation. However, due to their propensity to metastasize, the best outcomes are experienced with they are diagnosed early and treated aggressively. In this paper, we present a case of a CCOC misdiagnosed as a clear cell calcifying epithelial odontogenic tumour which was only found to be a CCOC after cervical node metastasis. The original diagnosis was questioned and confirmed to be a CCOC by identification of the chromosomal translocation EWSR1 on fluorescence in situ hybridization. This has recently been described in CCOC and a wide variety of other mesenchymal and epithelial neoplasms. Previous reports have demonstrated EWSR1-ATF1 and EWSR1-CREB1 fusions in CCOC. Next generation sequencing of this case demonstrated the EWSR1-CREM fusion gene which has not been previously reported for CCOC. CREM fusion proteins have only recently been found in several tumour types including the closely associated hyalinizing clear cell carcinoma of salivary glands. This is discussed in this paper, and the role of the discovery of the CREM fusion protein in CCOC adds to your understating of the role of CREM in oncogenesis, and the possible link between CCOCs and hyalinizing clear cell carcinomas.

Myoepithelial Carcinoma Ex Pleomorphic Adenoma of the Maxillary Sinus: A Case Report and Review of Literature.

Myoepithelial carcinoma ex pleomorphic adenoma is defined as a malignant epithelial neoplasm arising from a primary or recurrent benign pleomorphic adenoma. This type of tumor comprises 3.6% of all salivary gland tumors and 12% of malignant ones. Clinically, it most commonly presents as a firm mass in the parotid gland. The development of this neoplasm in the sinonasal and nasopharyngeal regions is extremely rare and only few cases are reported in the literature. The prognosis of myoepithelial carcinoma is variable. Marked cellular pleomorphism, high mitotic rate, and high proliferative activity correspond to a poor prognosis. In this article, the authors report the histopathological features of a clinical case of a 64-years-old patient with a large median maxillary neoplasm diagnosed as myoepithelial carcinoma/ex-pleomorphic adenoma. The tumor was resected and subjected to secondary reconstruction using a revascularized free fibula flap. The myoepithelial derivation of neoplastic cells was demonstrated by immunohistochemical positivity for S-100 protein (strong and diffuse), cytokeratin 14 (strong and diffuse), and GFAP (focal).

Giant cell tumor of the maxilla: an unusual neoplasm.

Giant cell tumors (GCT) of the bone are uncommon primary bone neoplasms that occur mainly in the epiphyses of long bones. Their incidence in craniofacial skeleton is rare, particularly in the maxilla. We report a case of a 12-year-old patient with a GCT of the left maxilla, who underwent a surgical excision of whole mass, and showed no recurrence one year after intervention.

Hemangiopericytoma of meningo-fronto-naso-orbito-maxillary complex.

Hemangiopericytoma (HPC) is a rare vascular tumour and difficult to diagnose clinically. Incidence is reported in fourth to fifth decade of life.With female predominance, 3%-5% cases affect the oral cavity, sinus lining and meninges. The patient presented with 8×6 cm swelling on her face, evaluation reported it to be HPC. Bilateral maxillary artery embolisation, wide local excision of the lesion, preserving the left eye and its function, was done. No recurrence is reported at 1-year follow-up. Response of such lesions to radiotherapy is questionable; with no lymphadenopathy and adequate encapsulation, embolisation of feeder vessel followed by a wide local excision of the lesion seems to be a fairly good option of treatment.

Odontogenic myxoma: ambiguous pathology of anterior maxilla.

Swellings in the anterior maxilla are uncommon and if present can be deemed as paradoxical conundrums presenting diagnostic and therapeutic dilemmas. Odontogenic myxoma is a rare, locally aggressive lesion that is primarily seen affecting the mandibular posterior region in association with an impacted tooth. It is found to be associated with odontogenesis. Treatment is usually surgical, with extent varying from curettage to resection. This report describes a rare case of odontogenic myxoma of the anterior maxilla in a 14-year-old boy, with an emphasis on its epidemiology, clinical presentation, histopathology, diagnosis and treatment planning.

A Rare Case of an Aggressive Clear Cell Variant of Calcifying Epithelial Odontogenic Tumor in the Posterior Maxilla.

A clear cell variant of calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm, accounting for 33 cases described in the literature. In this article, we report a challenging example of clear cell variant of calcifying epithelial odontogenic tumor of the posterior maxilla in a 45-year-old female patient showing locally aggressive growth and recurrence. Microscopically, islands of polyhedral cells containing abundant cytoplasm, well-developed intercellular bridges blended with clear cells were observed. The nuclei were frequently pleomorphic and permeated by hyaline calcified material. Immunohistochemistry revealed positivity for pan-cytokeratin (AE1/AE3), cytokeratins (CK-14 and CK-19), Bcl-2, p53, and p63. The Ki-67 proliferative index was ~10%. As odontogenic tumors are rare, when a significant clear cell component is observed, the differential diagnosis with other lesions of the jaws with similar morphology, including other odontogenic tumors with prominent clear cell component, clear cell odontogenic carcinomas, and metastatic tumors, is difficult.

Oral amelanotic malignant melanoma: a case report.

Amelanotic malignant melanoma is an extremely rare and aggressive oral tumor. Herein we report the case of a 42-year-old woman presented with a painful growth in anterior maxillary region. Intra-oral examination showed a non-pigmented exophytic mass occupying the anterior maxillary sector. Incisional biopsy with immunohistochemistry examination revealed a malignant melanoma as it strongly expressed melan A and S-100. Facial computed tomography showed extension to the maxillary bone and hard palate. After thoraco-abdominal computed tomography revealing absence of metastasis, tumor resection was performed respecting 2cm security margin. Oral localization of malignant melanoma is rare especially its amelanotic variant. Lack of pigmentation makes the diagnosis more difficult, usually resulting in treatment delay and making the prognosis even worse. Early detection by histological and immunochemistry examination combined to wide resection are the keys to improving the survival for patients with oral amelanotic melanoma.

Molecular findings in maxillofacial bone tumours and its diagnostic value.

According to the WHO, mesenchymal tumours of the maxillofacial bones are subdivided in benign and malignant maxillofacial bone and cartilage tumours, fibro-osseous and osteochondromatous lesions as well as giant cell lesions and bone cysts. The histology always needs to be evaluated considering also the clinical and radiological context which remains an important cornerstone in the classification of these lesions. Nevertheless, the diagnosis of maxillofacial bone tumours is often challenging for radiologists as well as pathologists, while an accurate diagnosis is essential for adequate clinical decision-making. The integration of new molecular markers in a multidisciplinary diagnostic approach may not only increase the diagnostic accuracy but potentially also identify new druggable targets for precision medicine. The current review provides an overview of the clinicopathological and molecular findings in maxillofacial bone tumours and discusses the diagnostic value of these genetic aberrations.

Rhabdomyosarcoma involving maxilla mimicking gingival enlargement: A diagnostic challenge.

Rhabdomyosarcoma (RMS) is a rare, rapidly growing, highly aggressive malignant neoplasm, originating from undifferentiated mesenchymal cells that retain their ability to differentiate into skeletal muscle. It mainly affects children, accounts for <1% of all adult malignancies and has varied clinical presentations. The head and neck region accounts for 35%-40% of all RMS cases, of which 10%-12% cases involve the oral cavity. This report deals with a case of RMS in a 40-year-old woman, primarily involving maxillary gingiva for which she underwent excision with subsequent recurrences. The uniqueness of this case is that it reminds us of the essential clinical dictum that 'every growth we encounter, no matter how benign it appears clinically, should be looked upon with suspicion'. Hence, proper integration of history, clinical examination and investigation is required to reach a correct diagnosis enabling early treatment, thereby preventing functional and aesthetic loss and psychological trauma.

Ameloblastic carcinoma: Clinicopathological analysis of 18 cases and a systematic review.

OBJECTIVES: Exploring the clinicopathological features of ameloblastic carcinoma (AC) and reviewing the literature to improve the diagnosis and treatment of the disease. MATERIALS AND METHODS: Clinical data and pathological features of 18 cases of AC were retrospectively analyzed. A systematic review was carried out by searching PubMed and Medline databases using the MeSH terms "ameloblastic" and "carcinoma." RESULTS: In the systematic analysis, 125 cases of AC from 81 eligible original studies and 18 cases of AC from this research were included. The male-to-female ratio was 2.58:1, and the mandible-to-maxilla ratio was 1.80:1. Mean age of patients was 45.3 years. Thirty-seven cases of recurrence and 27 cases of metastasis were recorded. CONCLUSION: AC is a rare neoplasm of the odontogenic epithelium. A systematic review indicates that diagnoses at the early phase and a close periodic assessment for recurrence and metastasis are necessary.

Lack of efficacy of neoadjuvant chemotherapy in adult patients with maxillo-facial high-grade osteosarcomas: A French experience in two reference centers.

INTRODUCTION: Neoadjuvant chemotherapy (neo-CT) for osteosarcomas is the standard of care. Management of maxillo-facial osteosarcomas (MFOS) is challenging. In this rare disease, we collected a large cohort of patients with the aim to report the histological and radiological local response rates to neo-CT. PATIENTS AND METHODS: All consecutive adult patients treated between 2001 and 2016 in two French sarcoma referral centers (Pitié-Salpêtrière Hospital, APHP, RESAP France and Gustave Roussy Institute France), for a histologically proved MFOS were included. Clinical, histological and radiological data were independently reviewed. Tumor response to neo-CT was assessed clinically, radiologically with independent review using RECIST v1.1 criterion and pathologically (percentage of necrosis). Multivariate analysis was done for outcomes, tumor response and disease-free survival (DFS). RESULTS: A total of 35 high grade MFOS were collected. The clinical tumor response was 4% (1/24 receiving neo-CT), the radiological response was 0% (0/18 with available data) and the pathological response was 5% (1/20 with available data). Three patients (12.5%) initially resectable became unresectable due to clinical and radiological progression during neo-CT. Tumor size and R0 (clear margins) surgical resections were significantly associated with DFS. CONCLUSION: MFOS is a rare disease. This large retrospective cohort of MFOS indicates the lack of benefit and potentially deleterious effects of neo-CT. We suggest privileging primary surgery in initially localized resectable MFOS. The benefit of adjuvant chemotherapy should be prospectively studied.