The diagnostic value of thyroglobulin concentration in fine-needle aspiration of the cervical lymph nodes in patients with differentiated thyroid cancer

INTRODUCTION: Recurrent differentiated thyroid cancer generally occurs first in the neck. Ultrasound is sensitive in detecting enlarged cervical lymph nodes but is not specific enough. Ultrasound-guided fine-needle biopsy increases the specificity but still may fail to detect a recurrence of the disease in the cystic metastatic lymph nodes. The aim of the study was to estimate the value of Tg concentration in the needle washout after fine-needle aspiration of suspicious lymph nodes. MATERIAL AND METHODS: The 105 patients studied had presented one or more enlarged suspicious cervical lymph nodes. All had undergone total thyroidectomy and (131)I ablative therapy. Serum thyroglobulin (Tg) concentration was within the 0.15-711.5 ng/ml range (mean 22.24 ng/ml) and Tg recovery range 94-100%. The positive Tg washout concentration cut-off value was established as equal to the mean plus two standard deviations of the Tg washout concentration of patients with negative cytology. RESULTS: Lymph node involvement was diagnosed by cytology in 15 patients and in 28 lymph nodes. Positive Tg washout concentration was found in 22 patients and in 48 lymph nodes. All the lymph nodes which turned out to have positive cytology had a positive Tg washout concentration. All lymph nodes with positive cytology were positive in pathology. Seven patients and 20 lymph nodes with negative cytology were positive in the Tg washout concentration test. All but one patients and all but two lymph nodes with a positive Tg washout concentration had positive pathology. CONCLUSIONS: 1. Ultrasound-guided fine-needle biopsy is not sensitive enough to detect all metastatic lymph nodes. 2. The Tg washout concentration test is 100% sensitive in the detection of metastatic lymph nodes. 3. Cytology in ultrasound- guided fine-needle biopsy is 100% specific. 4. The Tg washout concentration test carries a risk of false-positive results. 5. Both methods should be used for early detection of metastatic lymph nodes in patients with differentiated thyroid cancer.     

Hyperprolactinemia: causes, diagnosis, and treatment

The basic data on hyperprolactinemia (i.e. an excess of PRL above a reference laboratory's upper limits), the most common endocrine disorder of the hypothalamic-pituitary axis are given in this review. The following issues are discussed: regulation of prolactin (Prl) secretion, definition of hyperprolactinemia, its etiology and pathogenesis as well as its symptoms, diagnosis, and treatment (including medical and surgical therapy). It should be stressed that finding of elevated PRL serum concentrations constitute the beginning of diagnostic procedure and, after exclusion of physiologic, pharmacologic, and other organic causes of increased PRL levels, should be followed by detailed diagnosis including MRI. In patients in whom hyperprolactinemia has been confirmed the treatment with dopamine agonists (with prevalence of cabergoline, followed by quinagoline) is currently considered first-choice therapy. Surgery should be performed only in the patients resistant or intolerant to these agents, or in patients who refuse long-term therapy.     

Pheochromocytoma - chromaffin cell tumor

Pheochromocytoma is a rare tumor derived from chromaffin cells, which produces catecholamins. The presence of this tumor is considered a cause of secondary hypertension, arrhythmias, sweating and also, but very rarely, mental disorders. Update diagnostic methods of pheochromocytoma are summarized in this article. Pheochromocytoma also coexists with endocrinological syndroms, e.g. multiple endocrine neoplasia type 2 (MEN 2). Studies confirm genetic background of pheochromocytoma occurrence.     

A Vaccination Model for a Multi-City System

A modelling approach is used for studying the effects of population vaccination on the epidemic dynamics of a set of n cities interconnected by a complex transportation network. The model is based on a sophisticated mover-stayer formulation of inter-city population migration, upon which is included the classical SIS dynamics of disease transmission which operates within each city. Our analysis studies the stability properties of the Disease-Free Equilibrium (DFE) of the full n-city system in terms of the reproductive number R (0). Should vaccination reduce R (0) below unity, the disease will be eradicated in all n-cities. We determine the precise conditions for which this occurs, and show that disease eradication by vaccination depend on the transportation structure of the migration network in a very direct manner. Several concrete examples are presented and discussed, and some counter-intuitive results found.