No abstract

Nine cases with glandular odontogenic cysts (GOC's) are presented bringing the total number reported in the literature to 54. Our study confirmed that most GOC's occur in the mandible, whereas maxillary lesions present only in the globulo-maxillary region. The radiological features were found to be non-distinctive and presented as well-defined radiolucencies with uni- and multilocular appearances. Most of the mandibular GOC's were unilocular, involved the symphysis region and only one extended into the ramus. All GOC's larger than 6 cm in diameter showed perforated margins radiologically. Our two multilocular GOC's demonstrated microscopic features supporting their infiltrative radiological appearance. The invasive clinical and radiological features of GOC support the notion of a possible histo-pathologic overlap between GOC and low-grade central mucoepidermoid carcinoma of the jaw.

Two cases of peripheral odontogenic myxoma with a verifiable location in gingival soft tissue and without bone involvement were compared with those reported in the literature. This study showed that they form a distinct albeit rare clinical entity with a potential to grow into large disfiguring lesions. The probability that small peripheral odontogenic myxomas are interpreted as edematous irritation fibromas may contribute to the small number of peripheral odontogenic myxomas recorded in the literature. The differential diagnosis of soft tissue myxoid proliferations is discussed.

Owing to the unique population demographics of South Africa, odontogenic tumours in the first two decades of life comprise a larger percentage of the total number of cases than in other communities. The frequency of the different odontogenic tumour types generally follows the pattern of those reported in Africa, China and parts of South America. Radiographic examination is indispensable in establishing an accurate diagnosis.

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. Two ameloblastomas contained eosinophilic granules in all tumor cells and melanocytes were diffusely present in another. One case exhibited a focus of mucous cell metaplasia. Two polycystic ameloblastomas showed diffuse interstitial ossification. One mandibular tumor was diagnosed as a desmoplastic ameloblastoma and another as an odontoameloblastoma. This study demonstrated that although ameloblastomas are regarded as a fairly homogeneous group of neoplasms, detailed investigations prove clinicopathologic diversity in a significant number of lesions.