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At least 73 records · Page 4Linked to original sources
PubMed1989

Histogenesis of salivary gland neoplasms: a postulate with prognostic implications.

In a continually renewing cell population, stem cells can be regarded as a reservoir of cells with a high capacity for self renewal that give rise to all differentiated progeny. They are the primary source for the generation and maintenance of cellular diversity and tissue homeostasis. In general, neoplasms manifest differentiation pathways similar to those found in the development and renewal of the normal tissues from which they arise. This feature serves as a basis for classification schemes of neoplasms and, as in the normal tissues, there is usually an inverse correlation between proliferative capacity and differentiation within the neoplasms. In our postulate of the histogenesis of salivary gland neoplasia, we evoke the stem cell model to account for the considerable phenotypic heterogeneity seen with these neoplasms. We further consider the neoplasms and, in particular, their myoepithelial constituencies to be manifestations of escape from normal regulatory mechanisms that determine differentiation pathways which a stem cell and its progeny can take. Clinical and basic scientific evidence are presented to support the postulate and also to point to the mitigating role that myoepithelial differentiation has in the biological course of salivary gland neoplasms.

Cell Differentiation↗
PubMedDate not supplied

Pathology consultation. Metastatic patterns of salivary gland neoplasms.

Long-term follow-up of salivary gland carcinomas allows a better evaluation of their biologic malignancy than the traditional five-year period. Metastases (distant and local) are possible over the entire lifetime of a patient and are dependent upon histologic grade, persistence of neoplasm and clinical stage. Distant metastases to bone and lungs are manifested by nearly every carcinoma. Metastases to regional lymph nodes vary according to histologic type and it appears that the adenoid cystic carcinoma has the lowest incidence of that event.

Carcinoma↗
PubMed1985

A role for electron microscopy in salivary gland neoplasms.

Undoubtedly, electron microscopy has a specific role to play in the diagnosis of a select group of salivary gland neoplasms. However, this tool has a current central role, along with immunohistochemical techniques, in elucidating morphogenetic processes in salivary gland tumors. New information gained from ultrastructural surveys of these tumors can be applied to improving classification and the diagnostic problems that are not infrequent for the surgical pathologist with salivary gland lesions.

Adenoma↗
PubMed1986

Intra-oral salivary gland neoplasms: a retrospective study of 98 cases.

The findings of a retrospective study of 98 minor salivary neoplasms are reported. The patient's ages ranged from 13-79 years and there was an equal sex distribution. Sixty-one of the lesions were benign, 53 being pleomorphic adenomas and 8 monomorphic adenomas. Of the malignant tumors, 19 were muco-epidermoid tumors, 12 adenoid cystic carcinomas, 4 adenocarcinomas, 1 carcinoma ex-pleomorphic adenoma and 1 epidermoid carcinoma. One striking finding was the difference in age at the time of presentation for patients with muco-epidermoid tumors compared with those with adenoid cystic carcinomas. Seventy-four percent of the patients with muco-epidermoid tumors were under 50 years of age, but 75% of those with adenoid cystic carcinomas were over 50 years.

Adenoma, Pleomorphic↗
PubMed1999

Quantitative study on expression of p16 multiple tumor suppressor gene in salivary gland neoplasm.

The expression of p16 gene in normal salivary acini, benign tumors and carcinomas were microscopically and quantitatively observed by using immunohistochemical method LSAB and CMIASWIN methods. The expression of p16 gene were found in all 3 groups. The positive unit (PU) was higher in tumor group and cancer group than that in normal group (P < 0.01). Furthermore, the PU of p16 was stronger in cytoplasm than in nucleus. Malignant tumors and acini surrounding the tumor revealed strong positives and weak positives respectively. The PU of p16 gene was higher in deep lobe of recurrent parotid neoplasm with incomplete capsule than that in shallow lobe of primary parotid neoplasm with complete capsule. The findings suggests that p16 gene plays an equally important role in the salivary gland tumors and tumors in other part of the body.

Adenoma, Pleomorphic↗
PubMed1998

Tyrosine-rich crystals associated with oncocytic salivary gland neoplasms.

OBJECTIVE: Crystalloids have been identified ultrastructurally within the epithelial cells of Warthin's tumors, but there have been no studies characterizing crystals or crystalloids in Warthin's tumors by light microscopy. The finding of abundant needle-shaped crystals in a fine-needle aspirate of a cystadenoma of the parotid prompted us to examine the prevalence of crystals and crystalloids in oncocytic salivary gland neoplasms. DESIGN: Ninety-seven oncocytic neoplasms (93 Warthin's tumors, 3 cystadenomas, and 1 oncocytoma) excised at our institution between 1950 and 1996 were examined, to identify crystals. Neoplasms with crystals were further characterized by means of a variety of histochemical stains and electron microscopy. Ninety-nine pleomorphic adenomas were similarly reviewed. RESULTS: Seven cases with crystals were identified. Five of these were Warthin's tumors, 1 was a cystadenoma, and 1 was an oncocytoma. The crystals were noted within tumor cysts but were not limited to the neoplasms. The crystals were predominantly either needle-shaped or tabular, but some cases contained mixtures of both as well as intermediate forms. They stained pink with hematoxylin-eosin, although the tabular forms also exhibited a focal yellow hue. The crystals were not discernible under polarized light. They stained a red-brown color with Millon's reagent, which indicated the presence of tyrosine. Trichrome, periodic acid-Schiff stain with diastase, alcian blue (pH 2.5), and Congo red stains were negative. Electron microscopy revealed sharply defined, elongate, electron-dense structures with periodicity, both extracellular and within epithelial cells. No crystals or crystalloids were identified in any of 99 pleomorphic adenomas reviewed. CONCLUSIONS: The findings indicate that tyrosine-rich crystals associated with several oncocytic salivary gland neoplasms are morphologically, histochemically, and ultrastructurally distinct from previously described tyrosine-rich crystalloids and collagenous crystalloids of pleomorphic adenomas. Although the crystals appear to form by the assembly of small units within epithelial cells, the exact mode of formation remains unclear.

Adenolymphoma↗
PubMed2000

Objective biologic parameters and their clinical relevance in assessing salivary gland neoplasms.

This review summarizes research advances of cytometric, proliferation, cytogenetic, and molecular "objective" measurable parameters, as additional aids to prognostic information of salivary gland tumors provided by classical clinicopathologic indicators. Flow cytometric DNA ploidy and S-phase fraction seem to be of value as predictors of tumor behavior, aneuploidy, and high S-phase identifying an unfavorable clinical evolution of salivary gland neoplasms. Cell proliferation markers assessed by immunohistochemistry (e.g., PCNA, Ki-67) also appear to have predictive significance, but some conflicting results, in part related to technical procedures, limit their routine clinical application. Silver-stained methods (AgNORs) show a scarce value in estimating prognosis of salivary gland malignancies. p53 and c-erbB-2 as well as karyotyping, are of disputable benefit for clinical use, but the biologic information they provide give a better understanding on the molecular mechanisms involved in the development and progression of tumors. Further studies, with large databases, long follow-up information, uniformized histologic classification, and standardized methodologies, are needed to establish how these "objective" parameters would be of truly beneficial for the treatment of patients with salivary gland tumors.

Biomarkers, Tumor↗
PubMed1983

Amylase as an additional marker of salivary gland neoplasms. An immunoperoxidase study.

The presence of amylase in normal and neoplastic salivary gland tissue was investigated by immunoperoxidase techniques. Apart from normal and inflamed parotid glands, different kinds of tumours were studied with regard to amylase: acinic cell tumours, adenocarcinomas, adenoidcystic carcinomas, salivary duct carcinomas, mucoepidermoid tumours and squamous cell carcinomas. Amylase could be seen in acinic cell tumours, but not in other neoplasms. The results were discussed with respect to the diagnostic implications.

Adenocarcinoma↗
PubMed2006

Immunohistochemical localization of the NM23 protein in salivary gland neoplasms with distinct biological behavior.

The NM23 protein was shown to be associated with metastasis suppression in human malignancies with various tissue origins. However, its association with the metastatic phenotype of salivary gland neoplasms (SGN) remains unknown. To evaluate the role of NM23 in SGN, the expression patterns of NM23 in the following were compared: benign (pleomorphic adenoma) vs malignant (adenoid cystic carcinoma and mucoepidermoid carcinoma) SGN, and primary malignancies with/without evidence of metastasis vs their metastatic implants (MI). The lesions were studied immunohistochemically. NM23 protein was found in the cytoplasm of 75% of benign SGN, 73.3% of primary SGN malignancies with no evidence of metastasis, 86.6% of primary SGN malignancies with evidence of metastasis, and 60% of MI. There was no statistically significant difference in the frequency of NM23-positive cells between benign and primary malignant tumors (p = 0.79), nor between primary malignancies with/without evidence of metastasis and MI (p = 0.51). However, nuclear NM23 protein was restricted to primary SGN malignancies with evidence of metastasis and MI. The presence of nuclear NM23 protein may be a good marker for predicting the metastatic potential of SGN malignancies.

Humans↗
PubMed1978

[Methodological problems on the preparation and realization of multicientric field studies on mouth and salivary gland neoplasms].

The objectives of multicentric field trials are to provide a base for future revisions of the TNM system in order to ameliorate the existing classifications or to create new ones. The data are collected in a prospective and standardized manner and their evaluation is centralized. Therapy and follow-up in each case are registered at regular intervals and individual treatment is reported according to a standardized and flexible procedure. The particular methodological problem lies in the necessity of aligning the volume and quality of the desired information with the practicability of data collection.

Follow-Up Studies↗
PubMedDate not supplied

Adenoid cystic carcinoma: a third type of human salivary gland neoplasms characterized cytogenetically by reciprocal translocations.

Using G-banding technique, the chromosomes were studied in four consecutive preparations from cultured material from a human adenoid cystic carcinoma of the submandibular gland. The results indicated that the carcinoma had originated with a normal diploid stemline, and that reciprocal translocations played a predominant role in development of an abnormal stemline. The propensity of developing variant cells, as well as an abnormal stemline, characterized by various types of reciprocal translocations, was found to be a property shared by two other types of salivary gland neoplasms studied by banding techniques, namely the pleomorphic adenoma and the acinic cell tumour. The tissue of origin is suggested to be the crucial determinant responsible for this important cytogenetical similarity between different types of salivary gland tumours.

Adenocarcinoma↗
PubMed1983

An unusual parotid tumor with histogenetic implications for salivary gland neoplasms.

This case report describes an unusual parotid salivary gland tumor in which major proliferating elements arise in relation to well-differentiated, branching ducts. Both light and electron microscopic examination indicates that these ducts are formed by two distinct cell layers, an inner row of luminal epithelial cells and an outer layer of modified myoepithelial cells. It is from this outer layer of cells that discrete clusters of uniform basaloid cells develop. Although the majority of basaloid nests were relatively compact, a few showed a small number of clear, slightly widened, intercellular spaces which, ultrastructurally, were lined with basal lamina. Particularly in one area of the lesion, clusters of basaloid cells showed increasing numbers and sizes of these intercellular spaces with the gradual formation of an adenoid cystic pattern of differentiation. Even in this situation, however, luminal epithelial cells forming ducts could still be identified. The bidirectional cellular differentiation, the origin of basaloid clusters in relation to modified myoepithelial cells, and the mode of development of intercellular spaces resulting in an adenoid cystic pattern all have important implications for the histogenesis of salivary gland tumors.

Adenoma↗
PubMed1994

Staging of salivary gland neoplasms: role of histopathologic and molecular factors.

Cancer is a disease of altered cellular genes. These altered genes, in turn, produce the malignant phenotype by inducing changes in proliferation and differentiation during the cell cycle. The changes can be assessed by techniques to measure proliferation and by histologic grading to distinguish levels of differentiation. Since proliferation factors and differentiation end points reflect the net effect of genetic damage and include, therefore, the accumulated changes in genes, they more aptly qualify as potential prognostic indicators than do individual oncogene alterations. By using mucoepidermoid carcinoma of the major salivary glands as the test model, I strongly suggest that a reproducible (three-tiered) grading system and measurements of proliferation (nuclear markers: proliferating cell nuclear antigen and, possibly, Ki-67; and proliferation fraction as determined by flow cytometry) can serve as cellular/molecular factors worthy of inclusion in existing clinical staging systems of salivary gland neoplasms.

Biomarkers, Tumor↗