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The gastrointestinal system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Sharon J. White, Francis A. Carey
Odontogenic tumours are uncommon lesions derived from various tissue components involved in tooth development. Most are benign although malignant types do very rarely occur. The most frequently seen benign odontogenic tumours are odontomas and ameloblastoma. Odontomas are the most common odontogenic tumours and typically arise in childhood, when they often impede the eruption of a permanent tooth, and early adulthood. These tumours are hamartomatous lesions containing enamel and dentine and sometimes cementum. A complex odontoma consists of a disorganized mass of dental tissues, whereas a compound odontoma consists of numerous small tooth-like structures. Ameloblastoma is the second most common odontogenic tumour. It is derived from odontogenic epithelium and has a distinct histological appearance (Figure 10.5). Ameloblastoma most frequently arises in the molar region of the mandible. It is locally aggressive, often producing extensive bone destruction. The majority of ameloblastomas have been found to possess mutations in MAPK pathway genes.
Bone
Published in Joseph Kovi, Hung Dinh Duong, Frozen Section In Surgical Pathology: An Atlas, 2019
INCIDENCE: Ameloblastoma is a relatively rare lesion, and it represents about 1% of all tumors and cysts of the jaws. The tumor appears to be comparatively common in Africans; ameloblastoma constituted 29% of all tumors of the mandible and maxilla in Ghana.256
Cysts of the jaws, face and neck
Published in John Dudley Langdon, Mohan Francis Patel, Robert Andrew Ord, Peter Brennan, Operative Oral and Maxillofacial Surgery, 2017
One diagnostic and treatment dilemma for oral and maxillofacial surgeons involves the clinical and radiographic distinction between a dentigerous cyst and an enlarged dental follicle. This distinction becomes clinically significant when the surgeon considers whether to submit tissue removed with an impacted third molar for histopathologic examination as opposed to clinical designation as a follicle that may be discarded without microscopic analysis. The radiographic distinction becomes somewhat arbitrary; however, any pericoronal radiolucency that is larger than 4–5 mm is considered a cyst and should be submitted for microscopic examination. It is noteworthy that pathologists also struggle with the distinction between dental follicles associated with developing teeth and odontogenic lesions.3, 4 It seems that odontogenic cysts, odontogenic fibroma and odontogenic myxoma are the lesions most often incorrectly offered as diagnoses for follicles by surgical pathologists owing to a general unfamiliarity with the normal process of odontogenesis.3 Of perhaps even greater concern in terms of proper diagnosis and treatment is the large unilocular radiolucency. Although most commonly classified radiographically as dentigerous cysts, it is incumbent upon the surgeon to section these excised specimens in the operating room and to consider frozen-section analysis. This exercise is important so as to rule out the existence of a unicystic ameloblastoma that would at least require an aggressive curettage with curative intent.
Pulmonary resection for multiple lung metastasis from ameloblastoma: a rare case report and literature review
Published in Postgraduate Medicine, 2021
Guochao Zhang, Liang Zhao, Xuefei Wang, Bingzhi Wang, Wei Tang, Qi Xue
Ameloblastoma is a benign odontogenic epithelial neoplasm located mainly within the mandible and maxilla, accounting for nearly 1% of all odontogenic tumors [1]. The 4th edition of the World Health Organization (WHO) classification of odontogenous tumors has reclassified the terminology of ameloblastoma [2]. Metastasizing ameloblastoma is categorized as a type of benign epithelial odontogenic tumors in the new edition, whereas it was classified as a type of malignant ameloblastoma in the previous edition of the WHO classification [3]. Although they are always regarded as benign tumors, ameloblastomas could metastasize to other organs even following treatment with complete resection because of their locally aggressive behavior. The lung is the most likely metastatic site of ameloblastoma [4]. Due to its relative rarity, metastasizing ameloblastoma has become a controversial topic and has received much attention. Here, we report a rare case of multiple lung metastases from a mandibular ameloblastoma.
Ameloblastoma: a retrospective single institute study of 34 subjects
Published in Acta Odontologica Scandinavica, 2019
Jetta Kelppe, Jaana Hagström, Timo Sorsa, Anna Liisa Suominen, Satu Apajalahti, Caj Haglund, Hanna Thorén
Ameloblastoma is a benign, slowly growing, but locally aggressive odontogenic tumours originating from dental lamina and affecting primarily the jawbones. The risk of recurrence of ameloblastoma is high, reaching from 50% up to 90%. It affects equally men and women of all age groups, peaking in the fourth and fifth decades of life [1,2]. Ameloblastomas are divided into solid/multicystic, unicystic and peripheral ameloblastomas, and based on their histological growth pattern into follicular, plexiform, acanthomatous, granular cell, basal cell and desmoplastic ameloblastomas [2]. Signs or symptoms are subtle at the early stage, sometimes even non-existent but emerge progressively as the tumour grows. The treatment methods vary widely from conventional (enucleation, curettage, or surgical excision with peripheral osteotomy or adjuvant therapy) to radical (bone resection with 1 cm to 1.5 cm margins) [3]. The optimal treatment procedures remain a subject of debate [3,4].
Ameloblastoma: clinical presentation, multidisciplinary management and outcome
Published in Case Reports in Plastic Surgery and Hand Surgery, 2021
Abelardo Medina, Ignacio Velasco Martinez, Benjamin McIntyre, Ravi Chandran
We collected relevant demographics (i.e. age, gender, race, etc.), comorbidities and their therapeutic interventions, alcohol consumption, tobacco/marijuana use and body mass index (BMI). Characteristics of ameloblastoma clinical presentation (location, size, symptoms, histology, previous surgeries, etc.) were also reviewed. In addition, we compiled information on preoperative assessment (i.e. imaging studies, virtual surgical planning, blood tests, etc.), types of ablative and reconstructive surgeries, antibiotics and deep venous thrombosis (DVT) prophylaxes and nutritional assistance as well as operative complications, length of stay, secondary rehabilitation procedures and long-term outcomes.