BRAF(V600E) mutation in Turkish patients with papillary thyroid cancer: strong correlation with indicators of tumor aggressiveness.

Papillary thyroid cancer (PTC) constitutes more than 90% of the thyroid cancers. MAP kinase/ERK pathway plays an important role in the development of several cancers. BRAF which is a member of Raf-kinase family activates this way. BRAF gene activating mutations lead to neoplastic transformation in thyroid follicle cells. In PTC, this mutation itself is a poor prognostic sign independent of other clinicopathological characteristics. We evaluated BRAF(V600E) mutation and clinical-pathological characteristics in Turkish population with PTC. We assessed 109 patients with PTC (88 female, 21 male). The average age was 38.7 ± 9.9 (17-71). BRAF(V600E) mutation was detected using polymerase chain reaction and fluorescent melting curve analysis. The results show that BRAF(V600E) mutation rate was found in 39.45% of our patients. We observed that BRAF(V600E) mutation was significantly higher in men, in tumors larger than 1 cm in size, and in patients with classical PTC. Moreover, statistically significant correlations of BRAF(V600E) with indicators of tumor aggressiveness such as thyroid capsular invasion, multifocality, lymph node metastasis, and extrathyroidal spread were found. Patient groups below and over the age of 45 did not differ in mutation frequency. Patients with micro-PTC were evaluated separately, it was found that BRAF(V600E) mutation was more frequent in the classic type and that lymph node metastasis rate significantly increased when the mutation was present. We concluded that BRAF(V600E) was correlated with indicators of tumor aggressiveness in our study population. This fact is taken into consideration in treatment and follow-up of our patients with PTC and positive BRAF(V600E) mutation.

Parathyroid changes after high dose radioactive iodine in patients with thyroid cancer.

OBJECTIVE: The study aimed to investigate the effect of high dose radioactive iodine (RAI) on parathyroid function in patients with differentiated thyroid cancer. METHODS: Nineteen patients (8 men/11 women, age 46.5 +/- 13.2 years) undergoing RAI for thyroid remnant ablation were enrolled in the study. The biochemical parameters related to parathyroid function [serum calcium (Ca), phosphate (P), creatinine (Cr), alkaline phosphatase (ALP), intact parathyroid hormone (iPTH), urinary Ca, cAMP concentrations and the maximum tubular capacity for phosphate per unit volume of glomerular filtrate (TmP/GFR)] were evaluated at baseline and at the 1st, 3rd, 6th and 12th months of RAI administration. SPSS 15.0 was used for statistical analysis. RESULTS: For all patients, thyroid-stimulating hormone levels were >30 U/ml at baseline and <0.1 U/ml at the following visits. Serum iPTH levels were decreased significantly at the 6th month and reached basal levels at the 12th month (baseline vs. 6th p = 0.027, 1st vs. 6th p = 0.011, 3rd vs. 6th p = 0.047, 3rd vs. 12th p = 0.014, 6th vs. 12th p = 0.001). At the 6th month, P and TmP/GFR levels were higher (p = 0.036, 0.017, respectively), and urinary cAMP measurements were lower (p = 0.020) compared to those of the 1st month. No difference was detected concerning the other parameters. Serum Ca levels decreased below 2.1 mmol/l in several patients (n = 5 at 1st month, n = 4 at 3rd month, n = 8 at 6th month and n = 3 at 12th month) without clinical symptoms. CONCLUSIONS: The study indicated a transient decline in PTH levels at the 6th month following RAI therapy. Although this decrease did not cause symptoms in any of the present cases, this pattern might be important especially in individuals with diminished parathyroid background.

Co-secretion of aldosterone and cortisol by an adrenocortical carcinoma.

We report a rare case of adrenocortical carcinoma. A 26-year-old woman presented with hypokalemia and hypertension due to hyperaldosteronism. She had no signs of Cushing's syndrome. Endocrinological data showed excess of aldosterone production and nonsupressible cortisol production on 2 mg of dexamethasone. Magnetic resonance imaging showed left adrenal tumor. Transabdominal left adrenalectomy was performed and histopathological diagnosis was adrenocortical carcinoma. Her blood pressure and hypokalemia returned to normal after adrenalectomy. There is no recurrence after 36 months. We want to emphasis the importance of adrenal tests before the operation even if there are no signs of excess cortisol production.