ABSTRACT
The preoperative diagnostics of medullary thyroid carcinoma (MTC), including the measuring of the blood calcitonin level, has a number of limitations. Particular focus has recently been placed on the role of miRNAs in the development of various malignant tumors; a comparative analysis of accuracy of the existing methods for MTC diagnosis with a novel diagnosis method, evaluation of the miRNA-375 expression level, was performed in this study. The expression level of miRNA-375 in cytology samples from 555 patients with the known histological diagnosis, including 41 patients with confirmed postoperative diagnosis of MTC, was assessed. The diagnostic parameters of the basal calcitonin level, calcitonin in wash-out fluid from the FNAB needle, and miRNA-375 were compared. An assessment of the miRNA-375 expression level made it possible to detect all the MTC samples with a 100% accuracy among all the 555 cytology specimens, as well as in non-informative FNAB specimens, and specimens from the ipsilateral thyroid lobe. Parameters such as sensitivity, specificity, PPV, and NPV were 100%. The miRNA-375 level, unlike calcitonin, does not correlate with tumor volume, so it does not have the so-called "gray zone". An assessment of the miRNA-375 expression allows one to accurately distinguish MTC from other malignant and benign thyroid tumors.
ABSTRACT
Manifestations of pheochromocytoma have some specific features in children. The aim of this study was to explore epidemiologic differences of the disease course in children and adults, the principal causes of pheochromocytoma recurrence, and the optimal extent of an operative intervention in a group of patients with initial manifestation of their tumor during childhood. A total of 520 patients with pheochromocytoma underwent surgery from 1957 to 2001. The mean age of the patients was 39.3 +/- 9.2 years; 50 patients (9.6%) were 16 years or under (children's group). There were 213 males (41%) in the general group and 32 males (62%) in the children's group. Bilateral adrenal lesions were present in 68 patients (13.1%), including 16 of the 50 children (32%). The tumors were extraadrenal in 36 patients (6.9%), including 9 of the 50 children (18%). The combination of pheochromocytoma and a hereditary syndrome was present in 36 cases (6.9%). Follow-up was obtained in 260 patients, including 46 children. Length of follow-up varied from 4 to 25 years (average 8.4 +/- 1.9 years). The pheochromocytoma recurred in 49 patients (18.8% of surveyed patients), with a true recurrence (a tumor in the region of the primary operation or metastases) in 16 patients (6.15%). A true pheochromocytoma recurrence was noted in 6 of the 50 children (12.0%). Organ-sparing tactics for multicentric adrenal lesions was a principal cause of the true recurrence. Therefore we believe it is necessary to perform a radical operation, which includes adrenalectomy and removal of the tumor, in patients with a high risk of recurrence.
