Ultrastructural criteria of malignancy of adrenal medullary tumor.

Histological analysis and electron microscopy of 12 benign pheochromocytomas and 9 malignant pheochromoblastomas showed that there are no reliable histological differences between cells of benign and malignant tumor of the adrenal medulla. The ratio of ultrastructurally differentiated and undifferentiated cells in the tumor can reflect their maturity; the more ultrastructurally undifferentiated and less differentiated cells in the tumor, the higher is the malignant potential of this tumor.

[Immunomorphological characteristics of the infiltrative growth in well differentiated thyroid carcinoma]. / Immunomorfologicheskaia kharakteristika infil'trativnogo rosta vysokodifferentsirovannykh kartsinom shchitovidnoi zhelezy.

An immunomorphological study of 52 samples of normal thyroid tissue, 10 adenomas, 42 well differentiated carcinomas and 2 metastases has been performed using markers of the epithelium, extracellular matrix and angiogenesis. Basal keratin N 17 of the compound epithelium occurred only in malignant tumors. The highest number of the keratin N 17-positive cells was registered in sclerosing A-cell cancer, medullary and mixed C-cell cancer which is very aggressive. These cells locate in the foci of proliferation of tumor structures and in the regions of infiltrative growth. Multiple defects of basal membranes and prevalence of capillaries marked by antibodies to CD-31 over those identified by the antibodies to factor VIII were found in the areas of strong expression of keratin 17. Thus, the above markers detect foci of aggressive growth even in well differentiated thyroid carcinomas. This fact may be of prognostic value in oncomorphological practice.

[Expression of argyrophilic proteins from the nucleolar organizer regions as an index of maturity degree of benign and malignant adrenal tumors]. / Ekspressiia argirofil'nykh belkov oblastei iadryshkovogo organizatora kak pokazatel' stepeni zrelosti dobrokachestvennykh i zlokachestvennykh opukholei nadpochechnika.

Expression of APNOR was studied in 26 benign and malignant tumors of adrenal cortex and medulla. The histochemical method with silver nitrate was used. Expression of APNOR argyrophilic proteins in adrenocortical carcinomas was 4.59 times higher than in adrenocortical adenomas and 2.63 times higher in pheochromoblastomas than in pheochromocytomas. This index may be recommended as an additional method for differential diagnosis of benign and malignant adrenal tumors, particularly in difficult border line cases as well as determination of prognosis and metastatic potential of these tumors. Cytospecificity of APNOR expression in different types of adrenal cells was established.

[Neuroendocrine tumors of pancreas (clinicomorphological, immunohistochemical and electron microscopic study)]. / Neiroéndokrinnye opukholi podzheludochnoi zhelezy (kliniko-morfologice, immunogistokhimicheskoei élektronno-m ikroskopicheskoe issledovanie)

Neuroendocrine tumors of the pancreas were studied by histology, immunohistochemistry and electron microscopy. Tumors associated with organic hyperinsulinism showed heterogeneity in their ultrastructure, functional and proliferation activity. More than half of these tumors are multihormonal and 15% of them developed from polypotent cells which are capable for several types of differentiation.

Effects of low level radiation from the Chernobyl accident in a population with iodine deficiency.

UNLABELLED: To determine the effects of low dose radiation from 131I and 137Cs resulting from the Chernobyl disaster on the expression of endemic goiter in children, we studied children in regions with and without evidence of radiocontamination but comparable iodine insufficiency. We included 89 children in the study (radiocontaminated) region (SR) and 116 in the control region (CR) because they were either fetuses, infants, or pre-adolescents at the time of exposure. We evaluated thyroid dimensions by clinical examination and ultrasound; thyroid function by hormonal levels, and thyroglobulin measurement; histology of the thyroid by fine needle aspiration; and thyroid autoimmunity. SR subjects had 5 times the frequency of thyroid enlargement as those from CR, greatest in the younger patients. There were no instances of clinically apparent thyroid dysfunction. Antithyroid microsomal and antithyroglobulin antibodies were present in a markedly greater percentage of SR subjects. Fine needle biopsy demonstrated greater cellular proliferation in samples from SR. CONCLUSIONS: We have demonstrated findings of autoimmune thyroid disease at markedly increased frequency in a population of children with poor iodine nutriture who were exposed to low level radiation, compared to a more iodine deficient population not so exposed. These results suggest that low level radiation may induce thyroid gland changes in children who have inadequate iodine intake nutriture and reinforce the importance of adequate dietary iodine.