keratoameloblastoma

The term keratoameloblastoma has been used to describe a histologically heterogeneous group of ameloblastoma variants which have in common the formation of keratin by the ameloblastomatous epithelium. The English language literature contains reports of only 12 cases of keratoameloblastoma, of which 4 cases exhibited a papilliferous component. We report a unique tumor that we believe falls within the broad histopathologic spectrum of keratoameloblastoma. We review the key clinical and histopathologic features of the previously reported cases of keratoameloblastoma and present an additional case that presented as an expansile, radiolucent lesion with internal opacification between the roots of teeth in the left anterior maxillary alveolar ridge of a 45-year-old white male...

A case of an unusual lesion from the maxilla is presented. Macroscopically, the lesion was solid and histologically consisted of 'multiple separate keratocysts' of varying size that infiltrated into the surrounding bone and soft tissues. Panoramic image and CT scans showed a multilocular honeycomb ill-defined radiolucency with infiltration into the maxillary sinus and floor of orbit. This lesion should be differentiated from similar odontogenic lesions, such as keratoameloblastoma and papilliferous keratoameloblastoma...

We report a fourth case of papilliferous keratoameloblastoma, with a 6-year follow-up. A 62-year-old man underwent resection of a right mandibular neoplasm infiltrating bone and soft tissues. Microscopically, there were cysts lined by papillary projections and containing necrotic debris. Cribriform, solid, and tubular patterns were also present. No regional or distant metastases were found. A local recurrence, developed 3 years later, showed a predominance of the lesser differentiated patterns and focal granular cell ameloblastomatous features...

Keratoameloblastoma is an extremely rare variant of ameloblastoma, and a review of the English language literature yields only several documented cases of ketatoameloblastoma. This paper reports a keratoameloblastoma showing unique histological architecture. The patient was a 76-year-old Japanese man with a multilocular radiolucent lesion of the mandible extending from the left canine to the second molar area. Microscopically, the lesion was characterized by multicystic spaces lined by papillary projections of proliferating odontogenic epithelium with extensive surface parakeratinization in a lamellar accumulation of keratin...

The keratoameloblastoma is a rare histologic variant of the ameloblastoma. Review of the English language literature revealed five case reports of keratoameloblastoma. We report the sixth case of this tumor. The tumor developed in the right posterior maxilla of a 26-year-old African-American man and demonstrated aggressive clinical behavior, analogous to conventional ameloblastoma. The initial biopsy specimen showed extensive cyst formation, which histologically resembled odontogenic keratocyst. However, the lining epithelium varied in thickness and there was separation and edema between the basal cells and the rest of the epithelium...

One hundred and eight ameloblastomas diagnosed in a rural black Africa population were analysed for clinicopathologic findings other than those classically described. One patient had a polycystic ameloblastoma adjacent to an ameloblastic fibroma. Two other polycystic ameloblastomas showed aneurysmal bone cyst formation and one mandibular tumour was diagnosed as a keratoameloblastoma. Microscopic changes resembling an adenomatoid odontogenic tumour were present in association with two unicystic ameloblastomas and a HPV18-positive verrucous lesion occurred in the lining of a cystic space of a polycystic ameloblastoma...

An unusual case of ameloblastoma which depicts cystic follicles containing orthokeratin, parakeratin, desquamated epithelium and necrotic material with dystrophic calcification is presented. The presence of ameloblast-like cells confirms the diagnosis of an ameloblastoma. However, certain features resembled those of the keratoameloblastoma and others, less convincively, the papilliferous keratoameloblastoma. The extensive keratinisation in this tumour and in the aforementioned neoplasms raises the question whether they represent variants of the acanthomatous ameloblastoma...

A case of papilliferous keratoameloblastoma is reported which is only the second ever documented. The patient was a 76-yr-old black woman with a large expansile multilocular radiolucency of the body, angle and ramus of the mandible. Histologically the lesion consisted of sheets of cystic follicles filled with necrotic debris and sometimes parakeratin. The vast majority of the follicles were lined by a papilliferous epithelium consisting of large rounded cells with centrally placed nuclei. True papillary projections with cores of connective tissue were also present...

In the "WHO histological typing of odontogenic tumors, jaw cysts and allied lesions", the authors recognize five distinct histologic types of ameloblastoma. A further histologic variant, the keratoameloblastoma, was first described by PINDBORG. A second case of a keratoameloblastoma is reported. This lesion occurred in the maxilla of a 28-year-old Caucasian male.