DNA cytophotometry of acinic cell carcinoma and its relation to prognosis

Clear cell neoplasms in salivary glands: clearly a diagnostic challenge

Although infrequent, salivary gland tumors with a dominant population of clear staining cells present problems in differential diagnosis. Mucoepidermoid carcinoma, acinic cell adenocarcinoma, "clear cell" oncocytoma, epithelial-myoepithelial carcinoma, clear cell adenocarcinoma, and metastatic renal cell carcinoma are considered in the differential diagnosis. This review focuses on this heterogenous group of clear cell neoplasms and attempts to clarify some of the features that help distinguish one neoplasm from another.

Quantitative multivariate analysis of myoepithelioma and myoepithelial carcinoma

The nuclear DNA content and morphologic data of 30 surgical samples (eight normal parotid gland, 12 myoepithelioma, and 10 myoepithelial carcinoma) were analyzed by the IBAS II analysis system. The results suggest that there are relationships between tumor ploidy distribution and prognosis, and that correct pathologic diagnosis can be obtained by the IBAS image system.

DNA flow cytometry of reclassified subtypes of malignant salivary gland tumors

Malignant salivary gland tumors are rare, constitute a heterogeneous group and are often difficult to diagnose histologically. This is borne out by the fact that in the present study 43.2% of 118 salivary gland tumors originally diagnosed as mucoepidermoid, acinic cell and adenoid cystic carcinomas had their original diagnosis altered upon reclassification. Patients with confirmed adenoid cystic carcinomas had a much worse prognosis than those with mucoepidermoid and acinic cell carcinomas. DNA flow cytometry showed that very few of the above mentioned three types of malignant neoplasms revealed aneuploid DNA stemlines, indicating that this is not a relevant prognostic tumor marker within the groups. However, several of the tumors that had their diagnosis changed, mostly to undifferentiated adeno- or squamous cell carcinomas, showed aneuploid DNA stemlines. The survival time of patients with aneuploid tumors was considerably reduced compared to those with diploid tumors. Among confirmed acinic cell, mucoepidermoid and adenoid cystic carcinomas the S-phase fraction was a significant prognostic factor, as it was among all tumors examined. This indicates that DNA aneuploidy and S-phase fractions are potential prognostic factors for malignant salivary gland tumors, and that DNA flow cytometry may assist the characterization of such tumors.

Cell proliferation correlates with prognosis in acinic cell carcinomas of salivary gland origin. Immunohistochemical study of 30 cases using the MIB 1 antibody in formalin-fixed paraffin sections

Immunohistochemical staining with the MIB 1 antibody was used to assess cell proliferation in 30 cases of acinic cell carcinoma of salivary glands. Until now, no prognostic factors have been available for these rare tumours. The MIB 1 monoclonal antibody recognizes the Ki-67 antigen in formalin-fixed, paraffin-embedded tissues. A MIB 1 index was developed as a means of expressing the percentage of MIB 1-positive tumour cell nuclei, and the tumours were scored without prior information of clinical behaviour. The staining results were then compared with the clinical outcome of the patients. All eight patients who developed tumour recurrences had MIB 1 indices higher than 5 per cent. Tumour recurrences could be predicted even in cases of bland morphology and low mitotic rate. Three patients died of their recurrent tumours, and had MIB 1 indices of 56.2, 12.7, 7.8 per cent in their primary tumours. Five of seven patients with MIB 1 indices higher than 10 per cent had unfavourable outcomes. None of the 17 patients with MIB 1 indices lower than 5 per cent developed recurrences during follow-up periods up to 30 years. The present results indicate that MIB 1 staining appears to be a significant prognostic factor in acinic cell carcinomas of salivary gland origin.

Evaluation of malignant grade of salivary gland tumors: studies by cytofluorometric nuclear DNA analysis, histochemistry for nucleolar organizer regions and immunohistochemistry for p53

Investigations were carried out in 109 surgically resected salivary gland tumors, 46 adenomas and 63 carcinomas for nuclear DNA content by cytofluorometry, nucleolar organizer regions (AgNOR) by histochemistry and nuclear p53 accumulation by immunohistochemistry. The mean nuclear DNA content and the incidence of aneuploidy as well as the mean number of the AgNOR in carcinomas were significantly higher than those in adenomas. In the DNA histogram pattern, the aneuploidy frequently appeared in high grade carcinoma groups (adenocarcinoma, salivary duct carcinoma, carcinoma in pleomorphic adenoma and oncocytic carcinoma). Immunohistochemical nuclear p53 accumulation was observed in 15 tumors, of which ten showed DNA aneuploidy. In high grade carcinomas, DNA aneuploidy was closely related to p53 immunoreactivity. This study revealed that combined cytofluorometric nuclear DNA analysis, histochemical AgNOR count and immunoreactivity for p53 might be quite useful for evaluating the malignant grade of salivary gland tumors.

Heterogeneity of salivary gland tumors studied by flow cytometry

Intratumor DNA heterogeneity was investigated by flow cytometric analysis of multiple samples taken from different sites of 8 benign and 16 malignant primarily resected salivary gland tumors. All benign tumors had diploid DNA content. The overall incidence of DNA diploidy in 16 malignant cases examined was 50%. Intratumor differences in DNA ploidy were observed in four malignant tumors (25%); 2 of these 4 heterogeneous tumors contained both aneuploid and diploid cell clones. The remaining 12 tumors showed a homogeneous DNA content in the different specimens; 8 were diploid, 3 aneuploid, and 1 was polypoid. The DNA nondiploid tumors were clinically more advanced than the DNA diploid ones (p < 0.01). The tumor proliferation rate (fraction of cells in S-phase) was higher in DNA nondiploid samples than in diploid ones (p < 0.01). The DNA nondiploid tumors seemed to recur more often than DNA diploid ones did. The data emphasize the usefulness of DNA measurements for the characterization of malignant salivary gland tumors but also the importance of adequate sampling in assessing their DNA ploidy.

Histopathologic grading of salivary gland neoplasms: II. Acinic cell carcinomas

Acinic cell carcinomas display varied cytoarchitectural patterns of growth that should allow for formulation of histopathologic grading. Grading of these carcinomas may serve to identify subsets whose biologic behavior is more aggressive than the usually accepted low-grade behavior of acinic cell carcinomas as a group. To that end, a three-level histopathologic grading scheme is presented.

DNA flow cytometry of acinic cell carcinomas of major salivary glands

Fifteen acinic cell carcinomas from an equal number of patients were analysed for their DNA content and proliferative (S-phase) index by flow cytometry from archival tissues. Seven of the carcinomas manifested a diploid DNA content. None of the patients with diploid acinic cell carcinomas died of their carcinomas and none developed metastases in follow-up periods extending for 10 or more years. Four of eight patients with aneuploid acinic cell carcinomas have died because of their malignancies within a 10 year period after the first surgical removal of the carcinoma. Five of the eight patients exhibited metastases. Although the number of cases does not permit strong correlations between histopathological features, abnormalities in DNA content and outcome of patients, it was noted that carcinomas with prominent necrosis, tubuloductal differentiation and 'dedifferentiated' areas displayed more aggressive biological courses.

Acinic cell carcinoma of the salivary glands: the prognostic relevance of DNA cytophotometry in a retrospective study of long duration (1965-1987)

Acinic cell carcinomas of the Salivary Gland Registry, Institute of Pathology, University of Hamburg, West Germany, from 1965 to 1980 (n = 55) were evaluated retrospectively with respect to histologic, cytophotometric, and clinical data. The majority of the tumors (92.8%) were located in the parotid gland. Two thirds of the patients were female; one third were male. Mean age at primary diagnosis was 55.4 years. The tumors were graded into highly differentiated (76%) or less differentiated forms (24%) according to classic histologic and cytologic criteria. The clinical course was characterized by no recurrence in 15 cases; in 17 cases, recurrences developed, and 12 patients died of their tumor, some as late as 240 months after primary diagnosis. Differentiation showed a weak correlation with the clinical course. In 35 cases, nuclear DNA content of tumor cells was assessed cytochemically. The tumors were "diploid" or "near-diploid" in 34 cases; DNA content showed no correlation to the clinical course. As a result of long-term follow-up, it becomes evident that acinic cell carcinoma is prone to develop recurrences and metastases. Complete tumor removal during the primary operation seems to be important for controlling the disease inasmuch as the ostensible prognostic predictors evaluated here proved to be unreliable.

The relationship between nuclear DNA content in salivary gland tumors and prognosis. Comparison of mucoepidermoid tumors and acinic cell tumors

Differences in prognosis between salivary gland mucoepidermoid tumors and acinic cell tumors were compared by means of conventional histopathological grading and nuclear DNA content which was assessed cytochemically by a scanning cytophotometric procedure. The mucoepidermoid tumors were found to show a stronger correlation between histopathological grading and prognosis than did the acinic cell tumors. By using DNA quantification, valuable additional information could be obtained for predicting the behavior of the mucoepidermoid tumors, whereas there was no correlation between DNA content and prognosis for the acinic cell tumors. Regarding the relatively "benign" clinical course of most mucoepidermoid tumors, the term "tumor"--as proposed by the World Health Organization's classification--seems appropriate. In contrast, the more severe clinical courses of the acinic cell tumors justify the use of the term "carcinoma" instead.

Epithelial-myoepithelial duct carcinoma of salivary glands: a follow-up and cytophotometric study of 21 cases

The Salivary Gland Registry provided 21 cases of epithelial-myoepithelial duct carcinoma of salivary glands from 1965-1980 which were evaluated retrospectively for clinical follow-up and cytophotometric data; 81% were localized in the major, 19% in the minor salivary glands. The male:female ratio was 1:1.1, 10 patients (47.6%) being men and 11 (52.4%) women. The youngest patient was 27, the oldest 91 y old. The mean age was 59.3 y (overall), 57.9 y (women) and 61.0 (men). The clinical course was characterized by lymph node metastases present at initial diagnosis and local recurrences in 23.5%. No patient died of the tumor. In 12 cases, cytochemical assessment of nuclear DNA by means of single cell scanning cytophotometry yielded diploid histograms. According to clinical and cytophotometrical data, epithelial-myoepithelial duct carcinoma of salivary glands can be regarded as a proper tumor entity of low grade malignancy.