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Biomedical subjects

R J Melrose

Publications and source records attributed to R J Melrose.

At least 19 recordsLinked to original sources
PubMed2001

Premalignant oral mucosal diseases.

A premalignant phase in the development of oral cancer is predicted by the classic model of experimental epithelial carcinogenesis. Virtually all oral squamous cell carcinomas arise from a premalignant precursor, but it is difficult to specifically define the term premalignant. Oral pathologists use the term epithelial dysplasia to indicate microscopic features in a biopsy specimen that are associated with a risk of malignant change and then assign a grade of severity. There is good correlation between higher grades of dysplasia and increasing risk of cancer but less so with the lower grades. The clinical appearances manifested by oral epithelial dysplasia and early oral cancer include leukoplakia, erythroplakia, and speckled leukoplakia. This paper discusses and illustrates these clinical lesions, their associated risk factors, their relationship to epithelial dysplasia, and the associated risk of evolution into oral cancer.

Carcinoma, Squamous Cell↗
PubMed2001

Oral cancer: a self-assessment quiz.

This article consists of a quiz on oral cancer knowledge. The goals of the quiz are to reinforce known cancer information and present new information. Photographs are used to bring a sense of the practical problems that clinical pathology presents. Also, a number of real-life case situations are presented with their corresponding illustrations so that the readers may use their clinical judgment and experience in choosing an answer.

Adult↗
PubMed1999

Benign epithelial odontogenic tumors.

Teeth are formed from a complex interaction of primitive ectoderm and ectomesenchymal tissues. Because humans develop 2 sets of teeth (deciduous and permanent), odontogenesis is a prolonged biologic process. Residues of odontogenic tissues are present in most humans- both during and after odontogenesis. These elements may be found in either bone or soft tissue of the jaws and may contribute to the formation of odontogenic tumors in these sites. Further, the mixture of epithelium and mesenchyme necessary for tooth formation allows for the development of tumors composed of either element or for mixed neoplasms. This article discusses 4 of the 5 benign odontogenic neoplasms that are of epithelial origin and offers an agreed on classification scheme, which includes important clinicopathological subtypes. Specifically discussed are ameloblastoma, calcifying epithelial odontogenic tumor (Pindborg tumor), adenomatoid odontogenic tumor, and squamous odontogenic tumor. A brief history of each tumor is given along with a discussion of demographic data, clinical findings, radiographic features, and gross features where useful. A thorough discussion is presented of diagnostic histopathology including histologic variants. Generally accepted modes of therapy and follow-up recommendations are discussed.

Ameloblastoma↗
PubMed1997

Cancer awareness.

Explore the source record for details and available documents.

Education, Dental, Continuing↗
PubMed1992

Human ameloblastoma tumors express the amelogenin gene.

Instructive signals are responsible for the regulation of the expression of gene products characteristic of many cell lineages during normal development and potentially during neoplasia. The odontogenic origin of ameloblastomas is based largely on the similarity in histologic appearance between the tumor and the developing tooth organ. A pathognomonic pattern for odontogenic tissue-specific gene expression in ameloblastomas has not been previously shown. In these studies, the gene expression parameters for human ameloblastomas have been characterized with the techniques of messenger RNA phenotyping in combination with Northern and in situ hybridization analysis of messenger RNA. The results of these studies confirm that amelogenin, a gene transcribed solely by differentiated ameloblasts, was expressed by epithelial cells from human ameloblastomas. This observation suggests that the instructive signals required for ameloblast differentiation are shared during normal development and tumorigenesis of odontogenic epithelium.

Ameloblastoma↗
PubMed1991

Central odontogenic fibroma: clinicopathologic features of 19 cases and review of the literature.

The odontogenic fibroma is a benign neoplasm infrequently reported in the literature (20 cases). Nineteen additional examples are reported. This lesion occurs most frequently in the maxilla anterior to the molars and displays a striking female predilection. On occasion, it may be associated with an unerupted mandibular third molar. Histomorphologically, it is not encapsulated. A spectrum of fibrous connective tissue stroma is present: from myxoid to densely hyalinized and from relatively acellular to cellular. Calcification may or may not be present. It is distinguished by the presence of sparse cords and islands of inactive odontogenic epithelium. Enucleation or surgical curettage is appropriate therapy and recurrence is low. As there appears to be no correlation of histologic pattern with clinical behavior, it seems unnecessary to try to separate the tumor into two variants.

Adolescent↗
PubMed1990

Segmental odontomaxillary dysplasia. Report of eight cases and comparison with hemimaxillofacial dysplasia.

We report an analysis of eight cases with features as described for hemimaxillofacial dysplasia and compare our cases with those of that original report by Miles and associates. Patients were young and had bone and/or gingival enlargement, dental abnormalities, and unique radiographic and histologic features. Osseous and dental abnormalities were confined to the maxillary alveolus extending from the canine region to the tuberosity. Ipsilateral facial hypertrichosis was not observed. The condition seems to remain stable without significant progression and is hypothesized to be a developmental abnormality. We propose the term segmental odontomaxillary dysplasia (SOD) as a more precise descriptor for the constellation of features observed.

Adolescent↗
PubMed1990

Solid adenoid cystic carcinoma of the maxilla.

Seven cases of solid variant of adenoid cystic carcinoma of the maxilla are reported. Clinical and radiographic characteristics suggest origin within the maxillary alveolar bone. Swelling was minimal and disproportionate to the extensive, diffuse bone destruction universally present. Histologic features were typical of this neoplasm occurring in other sites and consisted of diffusely infiltrating islands of small, closely packed monomorphous cells with sparse cytoplasm, indistinct borders, and small hyperchromatic nuclei. Four of five patients with follow-up data died of their disease. This confirms the lethality of the solid variant. Rationale is presented for considering these malignancies to be of primary intraosseous origin.

Adult↗