Clear cell carcinoma of minor salivary gland of the tongue.

The case of a clear cell carcinoma of a minor salivary gland, at the basis of the tongue, is described, which represents 1% of malignant tumours of salivary glands. The biological behaviour is not very aggressive and development, which is very slow, is usually asymptomatic, and, indeed, the tumour often reaches considerable dimensions before being diagnosed. There are rare cases of local recurrence and distant metastases. Cases of salivary glands which have become sites of secondary localization of a clear cell tumour, originating in the kidneys, have been described. The interest in the form described here stems from the slow evolution and the considerable dimensions reached by the tumour before being diagnosed, despite development in a breathing or digestive area such as the oralpharyngeal tract. In the present case, computed axial tomography and nuclear magnetic resonance were used to reach the diagnosis. The patient was submitted to surgical treatment. In the differential diagnosis, it is necessary, from a pathological point of view, to take into consideration other neoplastic formations, such as acinar cell adenocarcinoma, epithelial-myoepithelial carcinoma, clear cell oncocytoma, sebaceous adenoma and sebaceous carcinoma.

[Nuclear DNA in neoplastic pathology of the thyroid gland]. / Il DNA nucleare nella patologia neoplastica della tiroide.

We have analysed the nuclear DNA content in a series of 33 thyroid tumours (18 carcinomas and 15 adenomas) and, for comparison, in 189 nodular strumas and 17 tissue samples of normal thyroids, calculating cell cycle parameters and presence of aneuploid DNA. Cell suspensions were prepared for each of three tissue fragments taken for different areas of the surgical specimens. Cell subpopulations with aneuploid DNA content were present in 39% of carcinomas, 27% of adenomas, 20% of strumas, but were absent in the samples from normal thyroids. The presence of hyperdiploid DNA was much more frequent than that of hypodiploid DNA in all pathologic tissues. The mean proliferation index was 14.1 in the carcinomas, 6.6 in the adenomas, 7.1 in the strumas and 6.1 in normal thyroid tissues. The percent of histograms with a coefficient of variation of the G0-G1 peak greater than 5 was highest in the carcinomas (26%). The significance and implications of the reported data are discussed for the interpretation of thyroid neoplastic pathologies.