Malignant odontogenic tumors

Abstract

Odontogenic tumors are represented by a clinically, radiographically and biologically diverse group of neoplasms of the jaws and surrounding soft tissues. They are derived from the epithelial, ectomesenchymal and/or mesenchymal elements of tooth forming tissues or their remnants. These tumors are uncommon, accounting for approximately 1 to 4% of all specimens processed in oral and maxillofacial pathology laboratories worldwide. In 2005 the World Health Organization updated their classification of benign and malignant odontogenic tumors. Based on this updated classification and a review of the international literature, odontogenic tumors are noted to be nearly exclusively cytologically benign tumors with an estimated incidence of malignant tumors in approximately 1 to 6% of all odontogenic tumors. An appreciation for odontogenic tumors as a whole, therefore, is incomplete without an understanding of the malignant odontogenic tumors. An historical perspective on these rare odontogenic malignancies permits this understanding with the recognition of their clinical, radiographic and histologic nuances. The following annotated references provide this very information. 1.Eversole LR. Malignant epithelial odontogenic tumors. Sem Diagn Path 16: 317-324, 1999. This paper provides a review of malignant epithelial odontogenic tumors prior to the establishment of the 2005 reclassification of odontogenic tumors by the World Health Organization. The authors refined the 1972 World Health Organization's classification of malignant neoplasms derived from odontogenic epithelium, and in so doing, developed an operational nosologic approach to these tumors in this paper. 2.Goldenberg D, Sciubba J, Koch W, Tufano RP. Malignant odontogenic tumors: a 22-year experience. Laryngoscope 114: 1770-1774, 2004. The authors of this paper reviewed 20 malignant odontogenic tumors among a series of 341 odontogenic tumors diagnosed during a 22 year time period between 1981 and 2002. Upon re-review of these 20 cases, the authors confirmed the presence of 9 cases of malignant odontogenic tumors including 4 cases of metastasizing ameloblastoma, 2 cases of ameloblastic carcinoma, and 1 case each of malignant Pindborg tumor, odontogenic ghost cell carcinoma, and squamous cell carcinoma arising in a keratocyst. The authors concluded that a pathologist with expertise in evaluating odontogenic neoplasms is essential to provide the proper diagnosis of these neoplasms. 3.Hall JM, Weathers DR, Unni KK. Ameloblastic carcinoma: an analysis of 14 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 103: 799-807, 2007. A clinicopathologic study of 14 cases of ameloblastic carcinoma of the jaws was provided among a series of 193 ameloblastomas diagnosed at the Mayo Clinic from 1902 to 2005. Eight cases were located in the mandible and 6 were located in the maxilla. The long-term findings in this study support the approach that surgical resection provides the best chance for survival compared to conservative surgical management with curettage in which case persistence of tumor inevitably occurred. 4.Kumaran PS, Anuradha V, Gokkulakrishnan S, Thambiah L, Jagadish AK, Satheesh G. Ameloblastic carcinoma: a case series. J Pharm Bioallied Sci Jul 6: S208-S211, 2014. A series of 6 cases of ameloblastic carcinoma of the jaws diagnosed by the authors from 2007-2012 is discussed. These cases were diagnosed among 71 cases of ameloblastoma during this time period. Two patients demonstrated cervical lymph node metastases. The authors recommended aggressive surgical resection of the ameloblastic carcinoma, including neck dissection, and reported that the utility of radiation therapy and chemotherapy is inconclusive. 5.Li J, Du H, Li P, Zhang J, Tian W, Tang W. Ameloblastic carcinoma: an analysis of 12 cases with a review of the literature. Oncology Letters 8: 914-920, 2014. The authors provided a review of 12 cases of ameloblastic carcinoma of the jaws. Eleven cases were located in the mandible and 1 case in the maxilla. The authors recommended aggressive surgical resection for proper management of these malignancies and indicated that postoperative radiation therapy is required. The requirement for cervical lymph node dissection for the ameloblastic carcinoma, however, remains unclear. 6.Martinez MM, Mosqueda-Taylor A, Carlos R, Delgado-Azanero W, de Almedia OP. Malignant odontogenic tumors: a multicentric Latin American study of 25 cases. Oral Diseases 20: 380-385, 2014. The authors reported the clinicopathologic features of 25 cases of malignant odontogenic tumors out of a total 2,142 odontogenic tumors diagnosed among 65,547 oral pathology specimens in Latin America. Nineteen cases were carcinomas including 8 cases of ameloblastic carcinoma and 5 cases of primary intraosseous carcinoma. Six cases were sarcomas, all of which were ameloblastic fibrosarcoma. 7.Slater LJ. Odontogenic malignancies. Oral Maxillofacial Surg Clin N Am 16: 409-424, 2004. This paper provided a review of odontogenic malignancies in preparation for the release of the 2005 World Health Organization reclassification of odontogenic tumors. In particular, the term metastasizing ameloblastoma was offered to appropriately substitute for the ambiguous term malignant ameloblastoma. 8.Slootweg PJ, Muller H. Malignant ameloblastoma or ameloblastic carcinoma. Oral Surg 57: 168-176, 1984. The authors recommended the use of the term malignant ameloblastoma to be applied to those lesions, that, in spite of a seemingly innocuous histology, have given origin to metastatic growths, while the term ameloblastic carcinoma be utilized as a term for lesions that combine features of an ameloblastoma with a less-differentiated histology that defines malignant disease. Two cases were reviewed to describe these concepts. 9.Van Dam SD, Unni KK, Keller EE. Metastasizing (malignant) ameloblastoma: review of a unique histopathologic entity and report of Mayo Clinic experience. J Oral Maxillofac Surg 68: 2962-2974, 2010. The authors reviewed 98 cases of metastasizing, malignant, or atypical ameloblastoma from the international literature of which 24 cases were classified as metastasizing ameloblastoma. To these cases the authors added 3 cases of metastasizing ameloblastoma from the Mayo Clinic files for a total of 27 cases. Eighty-one percent of cases originated in the mandible, recurring on average 4 times before metastasis. The lungs were the initial site of metastasis in 78% of cases of which 71% were bilateral. The average time from diagnosis of the primary tumor to metastasis was 18 years. 10.Woolgar JA, Triantafyllou A, Ferlito F, Devaney KO, Lewis JS, Rinaldo A, Slootweg PJ, Barnes L. Intraosseous carcinoma of the jaws: a clinicopathologic review. Part III: primary intraosseous squamous cell carcinoma. Head Neck 35: 906-909, 2013. This paper represents the third in a series of three papers reviewing the clinicopathologic features of intraosseous carcinoma of the jaws. This paper specifically deals with primary intraosseous squamous cell carcinoma of the jaws, including the histopathologic features, diagnostic difficulties, histogenesis and areas of uncertainty of this diagnosis.